BJT Amplifier Circuits

Size: px
Start display at page:

Download "BJT Amplifier Circuits"

Transcription

1 JT Amplifier ircuits As we have developed different models for D signals (simple large-signal model) and A signals (small-signal model), analysis of JT circuits follows these steps: D biasing analysis: Assume all capacitors are open circuit. Analyze the transistor circuit using the simple large signal mode as described in pp A analysis: 1) Kill all D sources 2) Assume coupling capacitors are short circuit. The effect of these capacitors is to set a lower cut-off frequency for the circuit. This is analyzed in the last step. 3) Inspect the circuit. If you identify the circuit as a prototype circuit, you can directly use the formulas for that circuit. Otherwise go to step 3. 3) eplace the JT with its small signal model. 4) Solve for voltage and current transfer functions and input and output impedances (nodevoltage method is the best). 5) ompute the cut-off frequency of the amplifier circuit. Several standard JT amplifier configurations are discussed below and are analyzed. For completeness, circuits include standard bias resistors and. For bias configurations that do not utilize these resistors (e.g., current mirror), simply set =. ommon ollector Amplifier (mitter Follower) D analysis: With the capacitors open circuit, this circuit is the same as our good biasing circuit of page 91 with c = 0. The bias point currents and voltages can be found using procedure of pages c V A analysis: To start the analysis, we kill all D sources: V = 0 c c 60L Lecture Notes, Spring

2 We can combine and into (same resistance that we encountered in the biasing analysis) and replace the JT with its small signal model: c v _ i r π β i i r o c i r π r o β i The figure above shows why this is a common collector configuration: collector is shared between input and output A signals. We can now proceed with the analysis. Node voltage method is usually the best approach to solve these circuits. For example, the above circuit will have only one node equation for node at point with a voltage : r π 0 r o β i 0 = 0 ecause of the controlled source, we need to write an auxiliary equation relating the control current ( i ) to node voltages: i = r π Substituting the expression for i in our node equation, multiplying both sides by r π, and collecting terms, we get: [ ( 1 (1 β) = 1 β r π 1 )] [ = 1 β r ] π r o r o Amplifier Gain can now be directly calculated: A v = 1 r π 1 (1 β)(r o ) Unless is very small (tens of Ω), the fraction in the denominator is quite small compared to 1 and A v 1. To find the input impedance, we calculate i i by KL: i i = i 1 i = r π 60L Lecture Notes, Spring

3 Since, we have i i = / or i i i = Note that is the combination of our biasing resistors and. With alternative biasing schemes which do not require and, (and, therefore ), the input resistance of the emitter follower circuit will become large. In this case, we cannot use. Using the full expression for from above, the input resistance of the emitter follower circuit becomes: i i i = [r π ( r o )(1 β)] and it is quite large (hundreds of kω to several MΩ) for. Such a circuit is in fact the first stage of the 741 OpAmp. The output resistance of the common collector amplifier (in fact for all transistor amplifiers) is somewhat complicated because the load can be configured in two ways (see figure): First,, itself, is the load. This is the case when the common collector is used as a current amplifier to raise the power level and to drive the load. The output resistance of the circuit is o as is shown in the circuit model. This is usually the case when values of o and A i (current gain) is quoted in electronic text books. V V c c = L L is the Load Separate Load c r π c r π i β i i β i r o r o L o o Alternatively, the load can be placed in parallel to. This is done when the common collector amplifier is used as a buffer (A v 1, i large). In this case, the output resistance is denoted by o (see figure). For this circuit, JT sees a resistance of L. Obviously, if we want the load not to affect the emitter follower circuit, we should use L to be much 60L Lecture Notes, Spring

4 larger than. In this case, little current flows in L which is fine because we are using this configuration as a buffer and not to amplify the current and power. As such, value of o or A i does not have much use. When is the load, the output resistance can be found by killing the source (short ) and finding the Thevenin resistance of the two-terminal network (using a test voltage source). c i r π r o β i i T v T o KL: i T = i v T r o β i KVL (outside loop): r π i = v T Substituting for i from the 2nd equation in the first and rearranging terms we get: o v T i T = (r o ) r π (1 β)(r o ) r π (r o) r π (1 β)(r o ) = r π (1 β) r π β = r e where we have used the fact that (1 β)(r o ) r π. When is the load, the current gain in this amplifier can be calculated by noting i o = / and i i / as found above: A i i o i i = In summary, the general properties of the common collector amplifier (emitter follower) include a voltage gain of unity (A v 1), a very large input resistance i (and can be made much larger with alternate biasing schemes). This circuit can be used as buffer for matching impedance, at the first stage of an amplifier to provide very large input resistance (such in 741 OpAmp). As a buffer, we need to ensure that L. The common collector amplifier can be also used as the last stage of some amplifier system to amplify the current (and thus, power) and drive a load. In this case, is the load, o is small: o = r e and current gain can be substantial: A i = /. Impact of oupling apacitor: Up to now, we have neglected the impact of the coupling capacitor in the circuit (assumed it was a short circuit). This is not a correct assumption at low frequencies. The coupling capacitor results in a lower cut-off frequency for the transistor amplifiers. In order to find the cut-off frequency, we need to repeat the above analysis and include the coupling capacitor 60L Lecture Notes, Spring

5 impedance in the calculation. In most cases, however, the impact of the coupling capacitor and the lower cut-off frequency can be deduced be examining the amplifier circuit model. onsider our general model for any amplifier circuit. If we assume that coupling capacitor is short circuit (similar to our A analysis of JT amplifier), v i =. V i c V i i o AV i Voltage Amplifier Model When we account for impedance of the capacitor, we have set up a high pass filter in the input part of the circuit (combination of the coupling capacitor and the input resistance of the amplifier). This combination introduces a lower cut-off frequency for our amplifier which is the same as the cut-off frequency of the high-pass filter: ω l = 2π f l = 1 i c Lastly, our small signal model is a low-frequency model. As such, our analysis indicates that the amplifier has no upper cut-off frequency (which is not true). At high frequencies, the capacitance between,, layers become important and a high-frequency smallsignal model for JT should be used for analysis. You will see these models in upper division courses. asically, these capacitances results in amplifier gain to drop at high frequencies. PSpice includes a high-frequency model for JT, so your simulation should show the upper cut-off frequency for JT amplifiers. I o Vo Z L ommon mitter Amplifier D analysis: ecall that an emitter resistor is necessary to provide stability of the bias point. As such, the circuit configuration as is shown has as a poor bias. We need to include for good biasing (D signals) and eliminate it for A signals. The solution to include an emitter resistance and use a bypass capacitor to short it out for A signals as is shown. c V Poor ias c V b Good ias using a by pass capacitor For this new circuit and with the capacitors open circuit, this circuit is the same as our good biasing circuit of page 91. The bias point currents and voltages can be found using procedure of pages L Lecture Notes, Spring

6 A analysis: To start the analysis, we kill all D sources, combine and into and replace the JT with its small signal model. We see that emitter is now common between input and output A signals (thus, common emitter amplifier. Analysis of this circuit is straightforward. xamination of the circuit shows that: = r π i = ( c r o ) β i A v = β r π ( c r o ) β r π c = c r e c i β i r r π o i = r π o = r o The negative sign in A ndicates 180 phase shift between input and output. The circuit has a large voltage gain but has a medium value for input resistance. As with the emitter follower circuit, the load can be configured in two ways: 1) c is the load. Then o = r o and the circuit has a reasonable current gain. 2) Load is placed in parallel to c. In this case, we need to ensure that L c. Little current will flow in L and o and A i values are of not much use. Lower cut-off frequency: oth the coupling and bypass capacitors contribute to setting the lower cut-off frequency for this amplifier, both act as a low-pass filter with: ω l (coupling) = 2π f l = 1 i c ω l (bypass) = 2π f l = 1 b o where (r e β ) In the case when these two frequencies are far apart, the cut-off frequency of the amplifier is set by the larger cut-off frequency. i.e., ω l (bypass) ω l (coupling) ω l = 2π f l = 1 i c ω l (coupling) ω l (bypass) ω l = 2π f l = 1 b When the two frequencies are close to each other, there is no exact analytical formulas, the cut-off frequency should be found from simulations. An approximate formula for the cut-off frequency (accurate within a factor of two and exact at the limits) is: ω l = 2π f l = 1 i c 1 b 60L Lecture Notes, Spring

7 ommon mitter Amplifier with mitter resistance A problem with the common emitter amplifier is that its gain depend on JT parameters A v (β/r π ) c. Some form of feedback is necessary to ensure stable gain for this amplifier. One way to achieve this is to add an emitter resistance. ecall impact of negative feedback on OpAmp circuits: we traded gain for stability of the output. Same principles apply here. c V D analysis: With the capacitors open circuit, this circuit is the same as our good biasing circuit of page 91. The bias point currents and voltages can be found using procedure of pages A analysis: To start the analysis, we kill all D sources, combine and into and replace the JT with its small signal model. Analysis is straight forward using node-voltage method. v r π v β i v r o = 0 v r o β i = 0 i = v r π (ontrolled source aux. q.) 1 v _ i r π β i i r o vo Substituting for i in the node equations and noting 1 β β, we get: v β v r π v r o v r o = 0 β v r π = 0 Above are two equations in two unknowns (v and ). Adding the two equation together we get v = ( / ) and substituting that in either equations we can find. Alternatively, we can find compact and simple solutions by noting that terms containing r o in the denominator are usually small as r o is quite large. In this case, the node equations simplify to (using r π /β = r e ): ( 1 v 1 ) = r e = r e (v ) = r e v = r e r e ( ) 1 r e = r e 60L Lecture Notes, Spring

8 Then, the voltage gain and input resistance can be easily calculated from the above equations: A v = = i = [β( r e )] r e As before the minus sign in A ndicates a 180 phase shift between input and output signals. Note the impact of negative feedback introduced by the emitter resistance. The voltage gain is independent of JT parameters and is set by and as r e (recall OpAmp inverting amplifier!). The input resistance is increased dramatically. To find o, we need to follow the procedure similar to that of page 107 to get: o = r o 1 1 β 1 r π r π r o 1 1 r π Assuming r o and r π, the above equation simplifies to: ( ) o r o 1 r e Lower cut-off frequency: The coupling capacitor together with the input resistance of the amplifer lead to a lower cut-off freqnecy for this amplifer (similar to emitter follower). The lower cut-off freqncy is geivn by: ω l = 2π f l = 1 i c 60L Lecture Notes, Spring

9 A Possible iasing Problem: The gain of the common emitter amplifier with the emitter resistance is approximately /. For cases when a high gain (gains larger than 5-10) is needed, may be become so small that the necessary good biasing condition, V = I > 1 V cannot be fulfilled. The solution is to use a by-pass capacitor as is shown. The A signal sees an emitter resistance of 1 while for D signal the emitter resistance is the larger value of = 1 2. Obviously formulas for common emitter amplifier with emitter resistance can be applied here by replacing with 1 as in deriving the amplifier gain, and input and output impedances, we short the bypass capacitor so 2 is effectively removed from the circuit. c V 1 2 b The addition of by-pass capacitor, however, modifies the lower cut-off frequency of the circuit. Similar to a regular common emitter amplifier with no emitter resistance, both the coupling and bypass capacitors contribute to setting the lower cut-off frequency for this amplifier. Similarly we find that an approximate formula for the cut-off frequency (accurate within a factor of two and exact at the limits) is: ω l = 2π f l = 1 i c 1 b where 2 (1 r e β ) 60L Lecture Notes, Spring

10 Summary of JT Amplifiers ommon ollector (mitter Follower): V A v = ( r o )(1 β) r π ( r o )(1 β) 1 c i = [r π ( r o )(1 β)] o = (r o ) r π (1 β)(r o ) r π r π β = r e 2π f l = 1 i c ommon mitter: V A v = β r π ( c r o ) β r π c = c r e i = r π o = r o 2π f l = 1 i c 1 b where (r e β ) c ommon mitter with mitter esistance: b c V = A v = r e i = [β( r e )] and o = r e ( r e 1 2π f l = 1 i c V ) A v = 1 r e 1 i = [β(1 r e )] o = r e ( r e 1 ) ω l = 2π f l = 1 i c 1 b = c 1 2 b where 2 (1 r e β ) If bias resistors are not present (e.g., bias with curent mirror), let. 60L Lecture Notes, Spring

11 xamples of Analysis and Design of JT Amplifiers xample 1: Find the bias point and A amplifier parameters of this circuit (Manufacturers spec sheets give: h fe = 200, h ie = 5 kω, h oe = 10 µs). r π = h ie = 5 kω r o = 1 h oe = 100 kω β = h fe = 200 r e = r π β = 25 Ω D analysis: 9 V eplace and with their Thevenin equivalent and proceed with D analysis (all D current and voltages are denoted by capital letters): 18k 0.47 µ F = 18 k 22 k = 9.9 kω V = = 4.95 V KVL: V = I V 10 3 I I = I 1 β = I ( ) = I 10 3 I = 4 ma I, KVL: I = I β V = V 10 3 I = 20 µa V = = 5 V D ias summary: I I = 4 ma, I = 20 µa, V = 5 V 22k V I V 1k 9 V I V 1k A analysis: The circuit is a common collector amplifier. Using the formulas in page 113, A v 1 i = 9.9 kω o r e = 25 Ω f l = ω l 2π = 1 2π c = 1 = 36 Hz 2π L Lecture Notes, Spring

12 xample 2: Find the bias point and A amplifier parameters of this circuit (Manufacturers spec sheets give: h fe = 200, h ie = 5 kω, h oe = 10 µs). r π = h ie = 5 kω r o = 1 h oe = 100 kω β = h fe = 200 r e = r π β = 25 Ω D analysis: 15 V eplace and with their Thevenin equivalent and proceed with D analysis (all D current and voltages are denoted by capital letters). Since all capacitors are replaced with open circuit, the emitter resistance for D analysis is = 510 Ω. 4.7 µ F 34 k 1 k = 5.9 k 34 k = 5.0 kω V = = 2.22 V k µ F KVL: V = I V 510I I = I 1 β = I ( ) = I 510 1k 15 V I = 3 ma I, KVL: I = I β = 15 µa V = 1000I V 510I V = 15 1, = 10.5 V D ias: I I = 3 ma, I = 15 µa, V = 10.5 V V I V I V = 510 A analysis: The circuit is a common collector amplifier with an emitter resistance. Note that the 240 Ω resistor is shorted out with the by-pass capacitor. It only enters the formula for the lower cut-off frequency. Using the formulas in page 113: A v = 1 r e = i = 5.0 kω 1, = 3.39 ( ) o r e 1 = 1.2 M Ω r e = 2 (1 r e 5, 000 ) = 240 ( β 200 ) = 137 Ω f l = ω l 2π = 1 1 2π i c 2π = b 60L Lecture Notes, Spring

13 1 2π 5, = 31.5 Hz 6 2π L Lecture Notes, Spring

14 xample 3: Design a JT amplifier with a gain of 4 and a lower cut-off frequency of 100 Hz. The Q point parameters should be I = 3 ma and V = 7.5 V. (Manufacturers spec sheets give: β min = 100, β = 200, h ie = 5 kω, h oe = 10 µs). r π = h ie = 5 kω r o = 1 h oe = 100 kω r e = r π β = 25 Ω V The prototype of this circuit is a common emitter amplifier with an emitter resistance. Using formulas of page 113 (r e = r π /h fe = 25 Ω), c A v = r e = 4 The lower cut-off frequency will set the value of c. We start with the D bias: As V is not given, we need to choose it. To set the Q-point in the middle of load line, set V = 2V = 15 V. Then, noting I I,: V = I V I = ( ) = 2.5 kω V i v _ V _ i v Values of and can be found from the above equation together with the A gain of the amplifier, A V = 4. Ignoring r e compared to (usually a good approximation), we get: = 4 4 = 2.5 kω = 500 Ω, = 2. kω ommercial values are = 510 Ω and = 2 kω. Use these commercial values for the rest of analysis. We need to check if V > 1 V, the condition for good biasing. V = I = = 1.5 > 1, it is OK (See next example for the case when V is smaller than 1 V). We now proceed to find and V. is found from good bias condition and V from a KVL in loop: (β 1) = 0.1(β min 1) = = 5.1 kω KVL: V = I V I V = = 2.28 V 60L Lecture Notes, Spring

15 ias resistors and are now found from and V : = = = 5 kω V V = = = can be found by dividing the two equations: = 33 kω. is found from the equation for V to be = 5.9 kω. ommercial values are = 33 kω and = 6.2 kω. Lastly, we have to find the value of the coupling capacitor: ω l = 1 i c = 2π 100 Using i = 5.1 kω, we find c = F or a commercial values of c = 300 nf. So, are design values are: = 33 kω, = 6.2 kω, = 510 Ω, = 2 kω. and c = 300 nf. xample 4: Design a JT amplifier with a gain of 10 and a lower cut-off frequency of 100 Hz. The Q point parameters should be I = 3 ma and V = 7.5 V. A power supply of 15 V is available. Manufacturers spec sheets give: β min = 100, h fe = 200, r π = 5 kω, h oe = 10 µs. r π = h ie = 5 kω r o = 1 h oe = 100 kω r e = r π β = 25 Ω V The prototype of this circuit is a common emitter amplifier with an emitter resistance. Using formulas of page 113: c A v = r e = 10 The lower cut-off frequency will set the value of c. We start with the D bias: As the power supply voltage is given, we set V = 15 V. Then, noting I I,: V = I V I = ( ) = 2.5 kω 60L Lecture Notes, Spring

16 Values of and can be found from the above equation together with the A gain of the amplifier A V = 10. Ignoring r e compared to (usually a good approximation), we get: = = 2.5 kω = 227 Ω, = 2.27 kω We need to check if V > 1 V which is the condition for good biasing: V = I = = 0.69 < 1. Therefore, we need to use a bypass capacitor and modify our circuits as is shown. For D analysis, the emitter resistance is 1 2 while for A analysis, the emitter resistance will be 1. Therefore: c V D ias: 1 2 = 2.5 kω 1 A gain: A v = 1 = 10 2 b Above are two equations in three unknowns. A third equation is derived by setting V = 1 V to minimize the value of 1 2. V V = (1 2 )I = = Now, solving for, 1, and 2, we find = 2.2 kω, 1 = 220 Ω, and 2 = 110 Ω (All commercial values). We can now proceed to find and V : V i i v v 1 2 (β 1)(1 2 ) = 0.1(β min 1)(1 2 ) = = 3.3 kω KVL: V = I V I V = = 1.7 V ias resistors and are now found from and V : = = = 3.3 kω V V = = 1 15 = L Lecture Notes, Spring

17 can be found by dividing the two equations: = 50 kω and is found from the equation for V to be = 3.6k Ω. ommercial values are = 51 kω and = 3.6k Ω Lastly, we have to find the value of the coupling and bypass capacitors: = 2 (1 r e 3, 300 ) = 110 ( β 200 ) = 77.5 Ω i = 3.3 kω ω l = 1 1 i c = 2π 100 b This is one equation in two unknown ( c and ) so one can be chosen freely. Typically b c as i. This means that unless we choose c to be very small, the cut-off frequency is set by the bypass capacitor. The usual approach is the choose b based on the cut-off frequency of the amplifier and choose c such that cut-off frequency of the i c filter is at least a factor of ten lower than that of the bypass capacitor. Note that in this case, our formula for the cut-off frequency is quite accurate (see discussion in page 109) and is ω l 1 b = 2π 100 This gives b = 20 µf. Then, setting 1 1 i c b 1 1 = 0.1 i c b i c = 10 b c = = 4.7 µf So, are design values are: = 50 kω, = 3.6 kω, 1 = 220 Ω, 2 = 110 Ω, = 2.2 kω, b = 20 µf, and c = 4.7 µf. An alternative approach is to choose b (or c ) and compute the value of the other from the formula for the cut-off frequency. For example, if we choose b = 47 µf, we find c = 0.86 µf. 60L Lecture Notes, Spring

18 xample 5: Find the bias point and A amplifier parameters of this circuit (Manufacturers spec sheets give: β = 200, r π = 5 kω, r o = 100 kω). This is a two-stage amplifier. The first stage (Tr1) is a common emitter amplifier and the second stage (Tr2) is an emitter follower. The two stages are coupled by a coupling capacitor (0.47 µf). D analysis: When we replace the coupling capacitors with open circuits, we see the that bias circuits for the two transistors are independent of each other. ach bias circuit can be solved independently. 33k 4.7 µ F 2k Tr1 6.2k V 0.47 µ F For Tr1, we replace the bias resistors (6.2k and 33k) with their Thevenin equivalent and proceed with D analysis: 18k 22k Tr2 1k = 6.2 k 33 k = 5.22 kω and V 1 = = 2.37 V KVL: V 1 = I 1 V I 1 I 1 = I 1 1 β = I 1 ( ) = I I 1 = 3.17 ma I 1, -KVL: I 1 = I 1 β = 16 µa V = I 1 V 1 500I 1 V 1 = = 7.1 V D ias summary for Tr1: I 1 I 1 = 3.17 ma, I 1 = 16 µa, V 1 = 7.1 V Following similar procedure for Tr2, we get: = 18 k 22 k = 9.9 kω and V 2 = = 8.25 V KVL: V 2 = I 2 V I 2 I 2 = I 2 1 β = I 2 ( ) = I L Lecture Notes, Spring

19 I 2 = 7.2 ma I 2, -KVL: I 2 = I 2 β V = V I 2 = 36 µa V 2 = = 7.8 V D ias summary for T2: I 2 I 2 = 7.2 ma, I 2 = 36 µa, V 2 = 7.8 V A analysis: We start with the emitter follower circuit (Tr2) as the input resistance of this circuit will appear as the load for the common emitter amplifier (Tr1). Using the formulas in page 113: A v2 1 i2 = 9.9 kω f l2 = ω l2 2π = 1 2π c2 = 1 = 34 Hz 2π Since i2 = 9.9 kω is NOT much larger than the collector resistor of common emitter amplifier (Tr1), it will affect the first circuit. Following discussion in pages 106 and 111, the effect of this load can be taken into by replacing in common emitter amplifiers formulas with = L = i2 = 2 k 9.9 kω = 1.66 kω. A v1 = 1.66k 500 = 3.3 i1 = 5.22 kω f l1 = ω l1 2π = 1 2π c1 = 1 = 6.5 Hz 2π The overall gain of the two-stage amplifier is then A v = A v1 A v2 = 3.3. The input resistance of the two-stage amplifier is the input resistance of the first-stage (Tr1), i = 9.9 kω. To find the lower cut-off frequency of the two-stage amplifier, we note that: A v1 (jω) = A v1 1 jω l1 /ω and A v2 (jω) = A v2 1 jω l2 /ω A v (jω) = A v1 (jω) A v2 (jω) = A v1 A v2 (1 jω l1 /ω)(1 jω l2 /ω) From above, it is clear that the maximum value of A v (jω) is A v1 A v2 and the cut-off frequency, ω l can be found from A v (jω = ω l ) = A v1 A v2 / 2 (similar to procedure we used for filters). For the circuit above, since ω l2 ω l1 the lower cut-off frequency would be very close to ω l2. So, the lower-cut-off frequency of this amplifier is 34 Hz. 60L Lecture Notes, Spring

20 xample 6: Find the bias point and A amplifier parameters of this circuit (Manufacturers spec sheets give: β = 200, r π = 5 kω, r o = 100 kω). This is a two-stage amplifier. The first stage (Tr1) is a common emitter amplifier and the second stage (Tr2) is an emitter follower. The circuit is similar to the twostage amplifier of xample 5. The only difference is that Tr2 is directly biased from Tr1 and there is no coupling capacitor between the two stages. This approach has its own advantages and disadvantages that are discussed at the end of this example. 2k I 1 33k I µ F I 1 Tr1 6.2k 500 V 2 15 V Tr2 1k D analysis: Since the base current in JTs are typically much smaller that the collector current, we start by assuming I 1 I 2. In this case, I 1 = I 1 I 2 I 1 I 1 (the bias current I 2 has no effect on bias parameters of Tr1). This assumption simplifies the analysis considerably and we will check the validity of this assumption later. For Tr1, we replace the bias resistors (6.2k and 33k) with their Thevenin equivalent and proceed with D analysis: = 6.2 k 33 k = 5.22 kω and V 1 = = 2.37 V KVL: V 1 = I 1 V I 1 I 1 = I 1 1 β = I 1 ( ) = I I 1 = 3.17 ma I 1, -KVL: I 1 = I 1 β = 16 µa V = I 1 V 1 500I 1 V 1 = = 7.1 V D ias summary for Tr1: I 1 I 1 = 3.17 ma, I 1 = 16 µa, V 1 = 7.1 V To find the bias point of T2, we note: V 2 = V I 1 = = 8.68 V 60L Lecture Notes, Spring

21 -KVL: V 2 = V I = 10 3 I 2 I 2 = 8.0 ma I 2, KVL: V = V I 2 I 2 = I 2 β = 40 µa V 2 = = 7.0 V D ias summary for T2: I 2 I 2 = 8.0 ma, I 2 = 40 µa, V 2 = 7.0 V We now check our assumption of I 1 I 2. We find I 1 = 3.17 ma I 2 = 41 µa. So, our assumption was justified. It should be noted that this bias arrangement is also stable to variation in transistor β. The bias resistors in the first stage will ensure that I 1 ( I 1 ) and V 1 is stable to variation of T1 β. Since V 2 = V 1 1 I 1, V 2 will also be stable to variation in transistor β. Finally, V 2 = V 2 2 I 2. Thus, I 2 ( I 2 ) will also be stable (and V 2 because of -KVL). A analysis: As in xample 5, we start with the emitter follower circuit (Tr2) as the input resistance of this circuit will appear as the load for the common emitter amplifier (Tr1). Using the formulas in page 113 and noting that this amplifier does not have bias resistors ( ): A v2 1 i2 = r π ( r o )(1 β) = = kω Note that because of the absence of the bias resistors, the input resistance of the circuit is very large, and because of the absence of the coupling capacitors, there is no lower cut-off frequency for this stage. Since i2 = kω is much larger than the collector resistor of common emitter amplifier (Tr1), it will NOT affect the first circuit. The parameters of the first-stage common emitter amplifier can be found using formulas of page 113. A v1 2, 000 = 500 = 4 i1 = 5.22 kω f l1 = ω l1 2π = 1 2π c1 = 1 = 6.5 Hz 2π L Lecture Notes, Spring

22 The overall gain of the two-stage amplifier is then A v = A v1 A v2 = 4. The input resistance of the two-stage amplifier is the input resistance of the first-stage (Tr1), i = 9.9 kω. The find the lower cut-off frequency of the two-stage amplifier is 6.5 Hz. The two-stage amplifier of xample 6 has many advantages over that of xample 5. It has three less elements. ecause of the absence of bias resistors, the second-stage does not load the first stage and the overall gain is higher. Also because of the absence of a coupling capacitor between the two-stages, the overall cut-off frequency of the circuit is lower. Some of these issues can be resolved by design, e.g., use a large capacitor for coupling the two stages, use a large 2, etc.. The drawback of the xample 6 circuit is that the bias circuit is more complicated and harder to design. In general, the saturation voltage for the amplifer is smaller compared to two-stage amplifier with a coupling capcitor between staes (such in xample 5). 60L Lecture Notes, Spring

BJT Amplifier Circuits

BJT Amplifier Circuits JT Amplifier ircuits As we have developed different models for D signals (simple large-signal model) and A signals (small-signal model), analysis of JT circuits follows these steps: D biasing analysis:

More information

VI. Transistor amplifiers: Biasing and Small Signal Model

VI. Transistor amplifiers: Biasing and Small Signal Model VI. Transistor amplifiers: iasing and Small Signal Model 6.1 Introduction Transistor amplifiers utilizing JT or FET are similar in design and analysis. Accordingly we will discuss JT amplifiers thoroughly.

More information

Transistor amplifiers: Biasing and Small Signal Model

Transistor amplifiers: Biasing and Small Signal Model Transistor amplifiers: iasing and Small Signal Model Transistor amplifiers utilizing JT or FT are similar in design and analysis. Accordingly we will discuss JT amplifiers thoroughly. Then, similar FT

More information

Lecture 12: DC Analysis of BJT Circuits.

Lecture 12: DC Analysis of BJT Circuits. Whites, 320 Lecture 12 Page 1 of 9 Lecture 12: D Analysis of JT ircuits. n this lecture we will consider a number of JT circuits and perform the D circuit analysis. For those circuits with an active mode

More information

Physics 623 Transistor Characteristics and Single Transistor Amplifier Sept. 13, 2006

Physics 623 Transistor Characteristics and Single Transistor Amplifier Sept. 13, 2006 Physics 623 Transistor Characteristics and Single Transistor Amplifier Sept. 13, 2006 1 Purpose To measure and understand the common emitter transistor characteristic curves. To use the base current gain

More information

Transistor Amplifiers

Transistor Amplifiers Physics 3330 Experiment #7 Fall 1999 Transistor Amplifiers Purpose The aim of this experiment is to develop a bipolar transistor amplifier with a voltage gain of minus 25. The amplifier must accept input

More information

Transistor Characteristics and Single Transistor Amplifier Sept. 8, 1997

Transistor Characteristics and Single Transistor Amplifier Sept. 8, 1997 Physics 623 Transistor Characteristics and Single Transistor Amplifier Sept. 8, 1997 1 Purpose To measure and understand the common emitter transistor characteristic curves. To use the base current gain

More information

Bipolar Transistor Amplifiers

Bipolar Transistor Amplifiers Physics 3330 Experiment #7 Fall 2005 Bipolar Transistor Amplifiers Purpose The aim of this experiment is to construct a bipolar transistor amplifier with a voltage gain of minus 25. The amplifier must

More information

MAS.836 HOW TO BIAS AN OP-AMP

MAS.836 HOW TO BIAS AN OP-AMP MAS.836 HOW TO BIAS AN OP-AMP Op-Amp Circuits: Bias, in an electronic circuit, describes the steady state operating characteristics with no signal being applied. In an op-amp circuit, the operating characteristic

More information

Lecture-7 Bipolar Junction Transistors (BJT) Part-I Continued

Lecture-7 Bipolar Junction Transistors (BJT) Part-I Continued 1 Lecture-7 ipolar Junction Transistors (JT) Part-I ontinued 1. ommon-emitter (E) onfiguration: Most JT circuits employ the common-emitter configuration shown in Fig.1. This is due mainly to the fact that

More information

LM 358 Op Amp. If you have small signals and need a more useful reading we could amplify it using the op amp, this is commonly used in sensors.

LM 358 Op Amp. If you have small signals and need a more useful reading we could amplify it using the op amp, this is commonly used in sensors. LM 358 Op Amp S k i l l L e v e l : I n t e r m e d i a t e OVERVIEW The LM 358 is a duel single supply operational amplifier. As it is a single supply it eliminates the need for a duel power supply, thus

More information

Transistors. NPN Bipolar Junction Transistor

Transistors. NPN Bipolar Junction Transistor Transistors They are unidirectional current carrying devices with capability to control the current flowing through them The switch current can be controlled by either current or voltage ipolar Junction

More information

Common-Emitter Amplifier

Common-Emitter Amplifier Common-Emitter Amplifier A. Before We Start As the title of this lab says, this lab is about designing a Common-Emitter Amplifier, and this in this stage of the lab course is premature, in my opinion,

More information

Lecture 30: Biasing MOSFET Amplifiers. MOSFET Current Mirrors.

Lecture 30: Biasing MOSFET Amplifiers. MOSFET Current Mirrors. Whites, EE 320 Lecture 30 Page 1 of 8 Lecture 30: Biasing MOSFET Amplifiers. MOSFET Current Mirrors. There are two different environments in which MOSFET amplifiers are found, (1) discrete circuits and

More information

Frequency Response of Filters

Frequency Response of Filters School of Engineering Department of Electrical and Computer Engineering 332:224 Principles of Electrical Engineering II Laboratory Experiment 2 Frequency Response of Filters 1 Introduction Objectives To

More information

BJT AC Analysis. by Kenneth A. Kuhn Oct. 20, 2001, rev Aug. 31, 2008

BJT AC Analysis. by Kenneth A. Kuhn Oct. 20, 2001, rev Aug. 31, 2008 by Kenneth A. Kuhn Oct. 20, 2001, rev Aug. 31, 2008 Introduction This note will discuss AC analysis using the beta, re transistor model shown in Figure 1 for the three types of amplifiers: common-emitter,

More information

Common Emitter BJT Amplifier Design Current Mirror Design

Common Emitter BJT Amplifier Design Current Mirror Design Common Emitter BJT Amplifier Design Current Mirror Design 1 Some Random Observations Conditions for stabilized voltage source biasing Emitter resistance, R E, is needed. Base voltage source will have finite

More information

Chapter 12: The Operational Amplifier

Chapter 12: The Operational Amplifier Chapter 12: The Operational Amplifier 12.1: Introduction to Operational Amplifier (Op-Amp) Operational amplifiers (op-amps) are very high gain dc coupled amplifiers with differential inputs; they are used

More information

LAB VIII. BIPOLAR JUNCTION TRANSISTOR CHARACTERISTICS

LAB VIII. BIPOLAR JUNCTION TRANSISTOR CHARACTERISTICS LAB VIII. BIPOLAR JUNCTION TRANSISTOR CHARACTERISTICS 1. OBJECTIVE In this lab, you will study the DC characteristics of a Bipolar Junction Transistor (BJT). 2. OVERVIEW In this lab, you will inspect the

More information

Fig6-22 CB configuration. Z i [6-54] Z o [6-55] A v [6-56] Assuming R E >> r e. A i [6-57]

Fig6-22 CB configuration. Z i [6-54] Z o [6-55] A v [6-56] Assuming R E >> r e. A i [6-57] Common-Base Configuration (CB) The CB configuration having a low input and high output impedance and a current gain less than 1, the voltage gain can be quite large, r o in MΩ so that ignored in parallel

More information

DIGITAL-TO-ANALOGUE AND ANALOGUE-TO-DIGITAL CONVERSION

DIGITAL-TO-ANALOGUE AND ANALOGUE-TO-DIGITAL CONVERSION DIGITAL-TO-ANALOGUE AND ANALOGUE-TO-DIGITAL CONVERSION Introduction The outputs from sensors and communications receivers are analogue signals that have continuously varying amplitudes. In many systems

More information

Using the Impedance Method

Using the Impedance Method Using the Impedance Method The impedance method allows us to completely eliminate the differential equation approach for the determination of the response of circuits. In fact the impedance method even

More information

Lab 7: Operational Amplifiers Part I

Lab 7: Operational Amplifiers Part I Lab 7: Operational Amplifiers Part I Objectives The objective of this lab is to study operational amplifier (op amp) and its applications. We will be simulating and building some basic op amp circuits,

More information

Homework Assignment 03

Homework Assignment 03 Question 1 (2 points each unless noted otherwise) Homework Assignment 03 1. A 9-V dc power supply generates 10 W in a resistor. What peak-to-peak amplitude should an ac source have to generate the same

More information

Design of op amp sine wave oscillators

Design of op amp sine wave oscillators Design of op amp sine wave oscillators By on Mancini Senior Application Specialist, Operational Amplifiers riteria for oscillation The canonical form of a feedback system is shown in Figure, and Equation

More information

Bipolar Junction Transistors

Bipolar Junction Transistors Bipolar Junction Transistors Physical Structure & Symbols NPN Emitter (E) n-type Emitter region p-type Base region n-type Collector region Collector (C) B C Emitter-base junction (EBJ) Base (B) (a) Collector-base

More information

LABORATORY 2 THE DIFFERENTIAL AMPLIFIER

LABORATORY 2 THE DIFFERENTIAL AMPLIFIER LABORATORY 2 THE DIFFERENTIAL AMPLIFIER OBJECTIVES 1. To understand how to amplify weak (small) signals in the presence of noise. 1. To understand how a differential amplifier rejects noise and common

More information

Basic Electronics Prof. Dr. Chitralekha Mahanta Department of Electronics and Communication Engineering Indian Institute of Technology, Guwahati

Basic Electronics Prof. Dr. Chitralekha Mahanta Department of Electronics and Communication Engineering Indian Institute of Technology, Guwahati Basic Electronics Prof. Dr. Chitralekha Mahanta Department of Electronics and Communication Engineering Indian Institute of Technology, Guwahati Module: 2 Bipolar Junction Transistors Lecture-2 Transistor

More information

LAB VII. BIPOLAR JUNCTION TRANSISTOR CHARACTERISTICS

LAB VII. BIPOLAR JUNCTION TRANSISTOR CHARACTERISTICS LAB VII. BIPOLAR JUNCTION TRANSISTOR CHARACTERISTICS 1. OBJECTIVE In this lab, you will study the DC characteristics of a Bipolar Junction Transistor (BJT). 2. OVERVIEW You need to first identify the physical

More information

How To Calculate The Power Gain Of An Opamp

How To Calculate The Power Gain Of An Opamp A. M. Niknejad University of California, Berkeley EE 100 / 42 Lecture 8 p. 1/23 EE 42/100 Lecture 8: Op-Amps ELECTRONICS Rev C 2/8/2012 (9:54 AM) Prof. Ali M. Niknejad University of California, Berkeley

More information

Transistor Biasing. The basic function of transistor is to do amplification. Principles of Electronics

Transistor Biasing. The basic function of transistor is to do amplification. Principles of Electronics 192 9 Principles of Electronics Transistor Biasing 91 Faithful Amplification 92 Transistor Biasing 93 Inherent Variations of Transistor Parameters 94 Stabilisation 95 Essentials of a Transistor Biasing

More information

OPERATIONAL AMPLIFIERS

OPERATIONAL AMPLIFIERS INTRODUCTION OPERATIONAL AMPLIFIERS The student will be introduced to the application and analysis of operational amplifiers in this laboratory experiment. The student will apply circuit analysis techniques

More information

Laboratory 4: Feedback and Compensation

Laboratory 4: Feedback and Compensation Laboratory 4: Feedback and Compensation To be performed during Week 9 (Oct. 20-24) and Week 10 (Oct. 27-31) Due Week 11 (Nov. 3-7) 1 Pre-Lab This Pre-Lab should be completed before attending your regular

More information

Lecture 22: Class C Power Amplifiers

Lecture 22: Class C Power Amplifiers Whites, EE 322 Lecture 22 Page 1 of 13 Lecture 22: lass Power Amplifiers We discovered in Lecture 18 (Section 9.2) that the maximum efficiency of lass A amplifiers is 25% with a resistive load and 50%

More information

Preamble. Kirchoff Voltage Law (KVL) Series Resistors. In this section of my lectures we will be. resistor arrangements; series and

Preamble. Kirchoff Voltage Law (KVL) Series Resistors. In this section of my lectures we will be. resistor arrangements; series and Preamble Series and Parallel Circuits Physics, 8th Edition Custom Edition Cutnell & Johnson Chapter 0.6-0.8, 0.0 Pages 60-68, 69-6 n this section of my lectures we will be developing the two common types

More information

Common Base BJT Amplifier Common Collector BJT Amplifier

Common Base BJT Amplifier Common Collector BJT Amplifier Common Base BJT Amplifier Common Collector BJT Amplifier Common Collector (Emitter Follower) Configuration Common Base Configuration Small Signal Analysis Design Example Amplifier Input and Output Impedances

More information

Application Note SAW-Components

Application Note SAW-Components Application Note SAW-Components Principles of SAWR-stabilized oscillators and transmitters. App: Note #1 This application note describes the physical principle of SAW-stabilized oscillator. Oscillator

More information

11: AUDIO AMPLIFIER I. INTRODUCTION

11: AUDIO AMPLIFIER I. INTRODUCTION 11: AUDIO AMPLIFIER I. INTRODUCTION The properties of an amplifying circuit using an op-amp depend primarily on the characteristics of the feedback network rather than on those of the op-amp itself. A

More information

Voltage Divider Bias

Voltage Divider Bias Voltage Divider Bias ENGI 242 ELEC 222 BJT Biasing 3 For the Voltage Divider Bias Configurations Draw Equivalent Input circuit Draw Equivalent Output circuit Write necessary KVL and KCL Equations Determine

More information

COMMON-SOURCE JFET AMPLIFIER

COMMON-SOURCE JFET AMPLIFIER EXPERIMENT 04 Objectives: Theory: 1. To evaluate the common-source amplifier using the small signal equivalent model. 2. To learn what effects the voltage gain. A self-biased n-channel JFET with an AC

More information

BJT Characteristics and Amplifiers

BJT Characteristics and Amplifiers BJT Characteristics and Amplifiers Matthew Beckler beck0778@umn.edu EE2002 Lab Section 003 April 2, 2006 Abstract As a basic component in amplifier design, the properties of the Bipolar Junction Transistor

More information

Objective. To design and simulate a cascode amplifier circuit using bipolar transistors.

Objective. To design and simulate a cascode amplifier circuit using bipolar transistors. ascode Amplifier Design. Objective. o design and simulate a cascode amplifier circuit using bipolar transistors. Assignment description he cascode amplifier utilises the advantage of the common-emitter

More information

Analog Signal Conditioning

Analog Signal Conditioning Analog Signal Conditioning Analog and Digital Electronics Electronics Digital Electronics Analog Electronics 2 Analog Electronics Analog Electronics Operational Amplifiers Transistors TRIAC 741 LF351 TL084

More information

Basic Op Amp Circuits

Basic Op Amp Circuits Basic Op Amp ircuits Manuel Toledo INEL 5205 Instrumentation August 3, 2008 Introduction The operational amplifier (op amp or OA for short) is perhaps the most important building block for the design of

More information

CHAPTER 10 OPERATIONAL-AMPLIFIER CIRCUITS

CHAPTER 10 OPERATIONAL-AMPLIFIER CIRCUITS CHAPTER 10 OPERATIONAL-AMPLIFIER CIRCUITS Chapter Outline 10.1 The Two-Stage CMOS Op Amp 10.2 The Folded-Cascode CMOS Op Amp 10.3 The 741 Op-Amp Circuit 10.4 DC Analysis of the 741 10.5 Small-Signal Analysis

More information

Operational Amplifier - IC 741

Operational Amplifier - IC 741 Operational Amplifier - IC 741 Tabish December 2005 Aim: To study the working of an 741 operational amplifier by conducting the following experiments: (a) Input bias current measurement (b) Input offset

More information

School of Engineering Department of Electrical and Computer Engineering

School of Engineering Department of Electrical and Computer Engineering 1 School of Engineering Department of Electrical and Computer Engineering 332:223 Principles of Electrical Engineering I Laboratory Experiment #4 Title: Operational Amplifiers 1 Introduction Objectives

More information

Small Signal Analysis of a PMOS transistor Consider the following PMOS transistor to be in saturation. Then, 1 2

Small Signal Analysis of a PMOS transistor Consider the following PMOS transistor to be in saturation. Then, 1 2 Small Signal Analysis of a PMOS transistor Consider the following PMOS transistor to be in saturation. Then, 1 I SD = µ pcox( VSG Vtp)^2(1 + VSDλ) 2 From this equation it is evident that I SD is a function

More information

Positive Feedback and Oscillators

Positive Feedback and Oscillators Physics 3330 Experiment #6 Fall 1999 Positive Feedback and Oscillators Purpose In this experiment we will study how spontaneous oscillations may be caused by positive feedback. You will construct an active

More information

Design of a TL431-Based Controller for a Flyback Converter

Design of a TL431-Based Controller for a Flyback Converter Design of a TL431-Based Controller for a Flyback Converter Dr. John Schönberger Plexim GmbH Technoparkstrasse 1 8005 Zürich 1 Introduction The TL431 is a reference voltage source that is commonly used

More information

Sophomore Physics Laboratory (PH005/105)

Sophomore Physics Laboratory (PH005/105) CALIFORNIA INSTITUTE OF TECHNOLOGY PHYSICS MATHEMATICS AND ASTRONOMY DIVISION Sophomore Physics Laboratory (PH5/15) Analog Electronics Active Filters Copyright c Virgínio de Oliveira Sannibale, 23 (Revision

More information

BJT AC Analysis 1 of 38. The r e Transistor model. Remind Q-poiint re = 26mv/IE

BJT AC Analysis 1 of 38. The r e Transistor model. Remind Q-poiint re = 26mv/IE BJT AC Analysis 1 of 38 The r e Transistor model Remind Q-poiint re = 26mv/IE BJT AC Analysis 2 of 38 Three amplifier configurations, Common Emitter Common Collector (Emitter Follower) Common Base BJT

More information

Measuring Insulation Resistance of Capacitors

Measuring Insulation Resistance of Capacitors Application Note Measuring Insulation Resistance of Capacitors A common use of high resistance measuring instruments (often called megohmmeters or insulation resistance testers) is measuring the insulation

More information

Figure 1: Common-base amplifier.

Figure 1: Common-base amplifier. The Common-Base Amplifier Basic Circuit Fig. 1 shows the circuit diagram of a single stage common-base amplifier. The object is to solve for the small-signal voltage gain, input resistance, and output

More information

Diodes and Transistors

Diodes and Transistors Diodes What do we use diodes for? Diodes and Transistors protect circuits by limiting the voltage (clipping and clamping) turn AC into DC (voltage rectifier) voltage multipliers (e.g. double input voltage)

More information

Op-Amp Simulation EE/CS 5720/6720. Read Chapter 5 in Johns & Martin before you begin this assignment.

Op-Amp Simulation EE/CS 5720/6720. Read Chapter 5 in Johns & Martin before you begin this assignment. Op-Amp Simulation EE/CS 5720/6720 Read Chapter 5 in Johns & Martin before you begin this assignment. This assignment will take you through the simulation and basic characterization of a simple operational

More information

The 2N3393 Bipolar Junction Transistor

The 2N3393 Bipolar Junction Transistor The 2N3393 Bipolar Junction Transistor Common-Emitter Amplifier Aaron Prust Abstract The bipolar junction transistor (BJT) is a non-linear electronic device which can be used for amplification and switching.

More information

2.161 Signal Processing: Continuous and Discrete Fall 2008

2.161 Signal Processing: Continuous and Discrete Fall 2008 MT OpenCourseWare http://ocw.mit.edu.6 Signal Processing: Continuous and Discrete Fall 00 For information about citing these materials or our Terms of Use, visit: http://ocw.mit.edu/terms. MASSACHUSETTS

More information

The basic cascode amplifier consists of an input common-emitter (CE) configuration driving an output common-base (CB), as shown above.

The basic cascode amplifier consists of an input common-emitter (CE) configuration driving an output common-base (CB), as shown above. Cascode Amplifiers by Dennis L. Feucht Two-transistor combinations, such as the Darlington configuration, provide advantages over single-transistor amplifier stages. Another two-transistor combination

More information

In a stereo, radio, or television, the input signal is small. After several. stages of voltage gain, however, the signal becomes large and uses the

In a stereo, radio, or television, the input signal is small. After several. stages of voltage gain, however, the signal becomes large and uses the chapter 12 Power Amplifiers In a stereo, radio, or television, the input signal is small. After several stages of voltage gain, however, the signal becomes large and uses the entire load line. In these

More information

ε: Voltage output of Signal Generator (also called the Source voltage or Applied

ε: Voltage output of Signal Generator (also called the Source voltage or Applied Experiment #10: LR & RC Circuits Frequency Response EQUIPMENT NEEDED Science Workshop Interface Power Amplifier (2) Voltage Sensor graph paper (optional) (3) Patch Cords Decade resistor, capacitor, and

More information

BIPOLAR JUNCTION TRANSISTORS

BIPOLAR JUNCTION TRANSISTORS CHAPTER 3 BIPOLAR JUNCTION TRANSISTORS A bipolar junction transistor, BJT, is a single piece of silicon with two back-to-back P-N junctions. However, it cannot be made with two independent back-to-back

More information

Superposition Examples

Superposition Examples Superposition Examples The following examples illustrate the proper use of superposition of dependent sources. All superposition equations are written by inspection using voltage division, current division,

More information

The BJT Differential Amplifier. Basic Circuit. DC Solution

The BJT Differential Amplifier. Basic Circuit. DC Solution c Copyright 010. W. Marshall Leach, Jr., Professor, Georgia Institute of Technology, School of Electrical and Computer Engineering. The BJT Differential Amplifier Basic Circuit Figure 1 shows the circuit

More information

Lecture 18: Common Emitter Amplifier. Maximum Efficiency of Class A Amplifiers. Transformer Coupled Loads.

Lecture 18: Common Emitter Amplifier. Maximum Efficiency of Class A Amplifiers. Transformer Coupled Loads. Whites, EE 3 Lecture 18 Page 1 of 10 Lecture 18: Common Emitter Amplifier. Maximum Efficiency of Class A Amplifiers. Transformer Coupled Loads. We discussed using transistors as switches in the last lecture.

More information

PIN CONFIGURATION FEATURES ORDERING INFORMATION ABSOLUTE MAXIMUM RATINGS. D, F, N Packages

PIN CONFIGURATION FEATURES ORDERING INFORMATION ABSOLUTE MAXIMUM RATINGS. D, F, N Packages DESCRIPTION The µa71 is a high performance operational amplifier with high open-loop gain, internal compensation, high common mode range and exceptional temperature stability. The µa71 is short-circuit-protected

More information

Dependent Sources: Introduction and analysis of circuits containing dependent sources.

Dependent Sources: Introduction and analysis of circuits containing dependent sources. Dependent Sources: Introduction and analysis of circuits containing dependent sources. So far we have explored timeindependent (resistive) elements that are also linear. We have seen that two terminal

More information

Bipolar Junction Transistor Basics

Bipolar Junction Transistor Basics by Kenneth A. Kuhn Sept. 29, 2001, rev 1 Introduction A bipolar junction transistor (BJT) is a three layer semiconductor device with either NPN or PNP construction. Both constructions have the identical

More information

Building the AMP Amplifier

Building the AMP Amplifier Building the AMP Amplifier Introduction For about 80 years it has been possible to amplify voltage differences and to increase the associated power, first with vacuum tubes using electrons from a hot filament;

More information

Fundamentals of Microelectronics

Fundamentals of Microelectronics Fundamentals of Microelectronics H1 Why Microelectronics? H2 Basic Physics of Semiconductors H3 Diode ircuits H4 Physics of Bipolar ransistors H5 Bipolar Amplifiers H6 Physics of MOS ransistors H7 MOS

More information

Lecture 060 Push-Pull Output Stages (1/11/04) Page 060-1. ECE 6412 - Analog Integrated Circuits and Systems II P.E. Allen - 2002

Lecture 060 Push-Pull Output Stages (1/11/04) Page 060-1. ECE 6412 - Analog Integrated Circuits and Systems II P.E. Allen - 2002 Lecture 060 PushPull Output Stages (1/11/04) Page 0601 LECTURE 060 PUSHPULL OUTPUT STAGES (READING: GHLM 362384, AH 226229) Objective The objective of this presentation is: Show how to design stages that

More information

Chapter 10. RC Circuits ISU EE. C.Y. Lee

Chapter 10. RC Circuits ISU EE. C.Y. Lee Chapter 10 RC Circuits Objectives Describe the relationship between current and voltage in an RC circuit Determine impedance and phase angle in a series RC circuit Analyze a series RC circuit Determine

More information

css Custom Silicon Solutions, Inc.

css Custom Silicon Solutions, Inc. css Custom Silicon Solutions, Inc. CSS555(C) CSS555/ PART DESCRIPTION The CSS555 is a micro-power version of the popular 555 Timer IC. It is pin-for-pin compatible with the standard 555 timer and features

More information

*For stability of the feedback loop, the differential gain must vary as

*For stability of the feedback loop, the differential gain must vary as ECE137a Lab project 3 You will first be designing and building an op-amp. The op-amp will then be configured as a narrow-band amplifier for amplification of voice signals in a public address system. Part

More information

Fig. 1 :Block diagram symbol of the operational amplifier. Characteristics ideal op-amp real op-amp

Fig. 1 :Block diagram symbol of the operational amplifier. Characteristics ideal op-amp real op-amp Experiment: General Description An operational amplifier (op-amp) is defined to be a high gain differential amplifier. When using the op-amp with other mainly passive elements, op-amp circuits with various

More information

LAB 12: ACTIVE FILTERS

LAB 12: ACTIVE FILTERS A. INTRODUCTION LAB 12: ACTIVE FILTERS After last week s encounter with op- amps we will use them to build active filters. B. ABOUT FILTERS An electric filter is a frequency-selecting circuit designed

More information

Lecture - 4 Diode Rectifier Circuits

Lecture - 4 Diode Rectifier Circuits Basic Electronics (Module 1 Semiconductor Diodes) Dr. Chitralekha Mahanta Department of Electronics and Communication Engineering Indian Institute of Technology, Guwahati Lecture - 4 Diode Rectifier Circuits

More information

Digital to Analog Converter. Raghu Tumati

Digital to Analog Converter. Raghu Tumati Digital to Analog Converter Raghu Tumati May 11, 2006 Contents 1) Introduction............................... 3 2) DAC types................................... 4 3) DAC Presented.............................

More information

Operational Amplifier as mono stable multi vibrator

Operational Amplifier as mono stable multi vibrator Page 1 of 5 Operational Amplifier as mono stable multi vibrator Aim :- To construct a monostable multivibrator using operational amplifier 741 and to determine the duration of the output pulse generated

More information

Constant Current Control for DC-DC Converters

Constant Current Control for DC-DC Converters Constant Current Control for DC-DC Converters Introduction... Theory of Operation... Power Limitations... Voltage Loop Stability...2 Current Loop Compensation...3 Current Control Example...5 Battery Charger

More information

Lecture 23: Common Emitter Amplifier Frequency Response. Miller s Theorem.

Lecture 23: Common Emitter Amplifier Frequency Response. Miller s Theorem. Whites, EE 320 ecture 23 Page 1 of 17 ecture 23: Common Emitter mplifier Frequency Response. Miller s Theorem. We ll use the high frequency model for the BJT we developed the previous lecture and compute

More information

Field-Effect (FET) transistors

Field-Effect (FET) transistors Field-Effect (FET) transistors References: Hayes & Horowitz (pp 142-162 and 244-266), Rizzoni (chapters 8 & 9) In a field-effect transistor (FET), the width of a conducting channel in a semiconductor and,

More information

SINGLE-SUPPLY OPERATION OF OPERATIONAL AMPLIFIERS

SINGLE-SUPPLY OPERATION OF OPERATIONAL AMPLIFIERS SINGLE-SUPPLY OPERATION OF OPERATIONAL AMPLIFIERS One of the most common applications questions on operational amplifiers concerns operation from a single supply voltage. Can the model OPAxyz be operated

More information

Scaling and Biasing Analog Signals

Scaling and Biasing Analog Signals Scaling and Biasing Analog Signals November 2007 Introduction Scaling and biasing the range and offset of analog signals is a useful skill for working with a variety of electronics. Not only can it interface

More information

Chapter 19 Operational Amplifiers

Chapter 19 Operational Amplifiers Chapter 19 Operational Amplifiers The operational amplifier, or op-amp, is a basic building block of modern electronics. Op-amps date back to the early days of vacuum tubes, but they only became common

More information

Bode Diagrams of Transfer Functions and Impedances ECEN 2260 Supplementary Notes R. W. Erickson

Bode Diagrams of Transfer Functions and Impedances ECEN 2260 Supplementary Notes R. W. Erickson Bode Diagrams of Transfer Functions and Impedances ECEN 2260 Supplementary Notes. W. Erickson In the design of a signal processing network, control system, or other analog system, it is usually necessary

More information

30. Bode Plots. Introduction

30. Bode Plots. Introduction 0. Bode Plots Introduction Each of the circuits in this problem set is represented by a magnitude Bode plot. The network function provides a connection between the Bode plot and the circuit. To solve these

More information

Application Report SLVA051

Application Report SLVA051 Application Report November 998 Mixed-Signal Products SLVA05 ltage Feedback Vs Current Feedback Op Amps Application Report James Karki Literature Number: SLVA05 November 998 Printed on Recycled Paper IMPORTANT

More information

Features. Ordering Information. * Underbar marking may not be to scale. Part Identification

Features. Ordering Information. * Underbar marking may not be to scale. Part Identification MIC86 Teeny Ultra Low Power Op Amp General Description The MIC86 is a rail-to-rail output, input common-mode to ground, operational amplifier in Teeny SC7 packaging. The MIC86 provides 4kHz gain-bandwidth

More information

V out. Figure 1: A voltage divider on the left, and potentiometer on the right.

V out. Figure 1: A voltage divider on the left, and potentiometer on the right. Living with the Lab Fall 202 Voltage Dividers and Potentiometers Gerald Recktenwald v: November 26, 202 gerry@me.pdx.edu Introduction Voltage dividers and potentiometers are passive circuit components

More information

Rectifier circuits & DC power supplies

Rectifier circuits & DC power supplies Rectifier circuits & DC power supplies Goal: Generate the DC voltages needed for most electronics starting with the AC power that comes through the power line? 120 V RMS f = 60 Hz T = 1667 ms) = )sin How

More information

Fully Differential CMOS Amplifier

Fully Differential CMOS Amplifier ECE 511 Analog Electronics Term Project Fully Differential CMOS Amplifier Saket Vora 6 December 2006 Dr. Kevin Gard NC State University 1 Introduction In this project, a fully differential CMOS operational

More information

http://users.ece.gatech.edu/~mleach/ece3050/notes/feedback/fbexamples.pdf

http://users.ece.gatech.edu/~mleach/ece3050/notes/feedback/fbexamples.pdf c Copyright 2009. W. Marshall Leach, Jr., Professor, Georgia Institute of Technology, School of Electrical and Computer Engineering. Feedback Amplifiers CollectionofSolvedProblems A collection of solved

More information

6.101 Final Project Report Class G Audio Amplifier

6.101 Final Project Report Class G Audio Amplifier 6.101 Final Project Report Class G Audio Amplifier Mark Spatz 4/3/2014 1 1 Introduction For my final project, I designed and built a 150 Watt audio amplifier to replace the underpowered and unreliable

More information

Lecture 7 Circuit analysis via Laplace transform

Lecture 7 Circuit analysis via Laplace transform S. Boyd EE12 Lecture 7 Circuit analysis via Laplace transform analysis of general LRC circuits impedance and admittance descriptions natural and forced response circuit analysis with impedances natural

More information

ENEE 307 Electronic Circuit Design Laboratory Spring 2012. A. Iliadis Electrical Engineering Department University of Maryland College Park MD 20742

ENEE 307 Electronic Circuit Design Laboratory Spring 2012. A. Iliadis Electrical Engineering Department University of Maryland College Park MD 20742 1.1. Differential Amplifiers ENEE 307 Electronic Circuit Design Laboratory Spring 2012 A. Iliadis Electrical Engineering Department University of Maryland College Park MD 20742 Differential Amplifiers

More information

AP-1 Application Note on Remote Control of UltraVolt HVPS

AP-1 Application Note on Remote Control of UltraVolt HVPS Basics Of UltraVolt HVPS Output Voltage Control Application Note on Remote Control of UltraVolt HVPS By varying the voltage at the Remote Adjust Input terminal (pin 6) between 0 and +5V, the UV highvoltage

More information

5B5BBasic RC Oscillator Circuit

5B5BBasic RC Oscillator Circuit 5B5BBasic RC Oscillator Circuit The RC Oscillator which is also called a Phase Shift Oscillator, produces a sine wave output signal using regenerative feedback from the resistor-capacitor combination.

More information

LR Phono Preamps. Pete Millett ETF.13. pmillett@hotmail.com

LR Phono Preamps. Pete Millett ETF.13. pmillett@hotmail.com LR Phono Preamps Pete Millett ETF.13 pmillett@hotmail.com Agenda A bit about me Part 1: What is, and why use, RIAA? Grooves on records The RIAA standard Implementations of RIAA EQ networks and preamps

More information

Supertex inc. HV256. 32-Channel High Voltage Amplifier Array HV256. Features. General Description. Applications. Typical Application Circuit

Supertex inc. HV256. 32-Channel High Voltage Amplifier Array HV256. Features. General Description. Applications. Typical Application Circuit 32-Channel High Voltage Amplifier Array Features 32 independent high voltage amplifiers 3V operating voltage 295V output voltage 2.2V/µs typical output slew rate Adjustable output current source limit

More information