Low-Cost, High-Speed, Single-Supply, Gain of +2 Buffers with Rail-to-Rail Outputs in SOT23

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1 9-; Rev ; / Low-Cost, High-Speed, Single-Supply, Gain of + Buffers with Rail-to-Rail Outputs in SOT General Description The MAX/MAX/MAX9/MAX are precision, closed-loop, gain of + (or -) buffers featuring high slew rates, high output current drive, and low differential gain and phase errors. These single-supply devices operate from +.V to +V, or from ±.V to ±.V dual supplies. The input voltage range extends mv beyond the negative supply rail and the outputs swing Rail-to-Rail. These devices require only.ma of quiescent supply current while achieving a MHz -db bandwidth and a V/µs slew rate. In addition, the MAX9 has a disable feature that reduces the supply current to µa. Input voltage noise for these parts is only nv/ Hz and input current noise is only.pa/ Hz. This buffer family is ideal for low-power/low-voltage applications that require wide bandwidth, such as video, communications, and instrumentation systems. For space-sensitive applications, the MAX comes in a tiny -pin SOT package. Selector Guide PART NO. OF AMPS ENABLE PIN-PACKAGE MAX No -Pin SOT MAX No -Pin SO/µMAX MAX9 Yes MAX No -Pin SO, -Pin QSOP -Pin SO, -Pin QSOP Features Internal Precision Resistors for Closed-Loop Gains of + or - High Speed: MHz -db Bandwidth MHz.dB Gain Flatness (MHz min) V/µs Slew Rate Single.V/.V Operation Outputs Swing Rail-to-Rail Input Voltage Range Extends Beyond VEE Low Differential Gain/Phase:.%/. Low Distortion at MHz: -dbc Spurious-Free Dynamic Range -db Total Harmonic Distortion High Output Drive: ±ma Low,.mA Supply Current µa Shutdown Supply Current Space-Saving SOT-, µmax, or QSOP Packages Ordering Information PART TEMP. RANGE PIN- PACKAGE SOT TOP MARK MAXEUK - C to + C SOT- ABZQ MAXESA - C to + C SO MAXEUA - C to + C µmax MAX9ESD - C to + C SO MAX9EEE - C to + C QSOP MAXESD - C to + C SO MAXEEE - C to + C QSOP MAX/MAX/MAX9/MAX Applications Portable/Battery-Powered Instruments Video Line Driver Analog-to-Digital Converter Interface CCD Imaging Systems Video Routing and Switching Systems Typical Operating Circuit Ω V Ω MAX Ω Ω IN- Rail-to-Rail is a registered trademark of Nippon Motorola Ltd. GAIN OF + VIDEO/RF CABLE DRIVER Maxim Integrated Products For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at --9-, or visit Maxim s website at

2 Low-Cost, High-Speed, Single-Supply, Gain of + Buffers with Rail-to-Rail Outputs in SOT MAX/MAX/MAX9/MAX ABSOLUTE MAXIMUM RATINGS Supply Voltage (V CC to V EE )...V IN_-, IN_+, _, EN_...(V EE -.V) to (V CC +.V) Output Short-Circuit Duration to V CC or V EE...Continuous Continuous Power Dissipation (T A = + C) -pin SOT (derate.mw/ C above+ C)...mW -pin SO (derate.9mw/ C above + C)...mW DC ELECTRICAL CHARACTERISTICS -pin µmax (derate.mw/ C above + C)...mW -pin SO (derate.mw/ C above + C)...mW -pin QSOP (derate.mw/ C above + C)...mW Operating Temperature Range...- C to + C Storage Temperature Range...- C to + C Lead Temperature (soldering, sec)...+ C Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or at any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. (V CC = +V, V EE = V, IN_- =V, EN_ = V, R L = to ground, V = V CC /, noninverting configuration, T A = T MIN to T MAX, unless otherwise noted. Typical values are at T A = + C.) (Note ) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Input Voltage Range V IN IN_+ V EE -. V CC -. IN_- V EE -. V CC +. V Input Offset Voltage V OS R L = Ω mv Input Offset Voltage Drift TC VOS µv/ C Input Offset Voltage Matching Any channels for MAX/MAX9/MAX ± mv Input Bias Current I B IN_+ (Note ). µa Input Resistance R IN IN_+, over input voltage range MΩ Voltage Gain A V R L Ω, (V EE +.V) V (V CC -.V).9. V/V Output Resistance R f = DC mω Output Current I R L = Ω to V CC or T A = + C ± ± ma V EE T A = T MIN to T MAX ± ma Short-Circuit Output Current I SC Sinking or sourcing ± ma R L = Ω V CC - V OH.. V OL - V EE.. Output Voltage Swing V R L =Ω V CC - V OH.. V OL - V EE.. V R L = kω V CC - V OH. V OL - V EE. V CC = V, V EE = V, V = V Power-Supply Rejection Ratio PSRR V (Note ) CC = V, V EE = -V, V = V V CC =.V, V EE = V, V =.9V db Operating Supply-Voltage Range V CC to V EE.. V Disabled Output Resistance R (OFF) MAX9, EN_ = V, V V V kω EN_ Logic-Low Threshold V IL MAX9 V CC -. V EN_ Logic-High Threshold V IH MAX9 V CC -. V (V EE +.V) EN_ V CC. EN_ Logic Input Low Current I IL MAX9 µa EN_ = V EE µa EN_ Logic Input High Current I IH. MAX9, EN_ = V CC Quiescent Supply Current (per Buffer) Enabled (EN_ = V CC).. I CC MAX9, disabled (EN_ = V EE ).. ma

3 Low-Cost, High-Speed, Single-Supply, Gain of + Buffers with Rail-to-Rail Outputs in SOT AC ELECTRICAL CHARACTERISTICS (V CC = +V, V EE = V, IN_- = V, EN_ = V, R L = Ω to ground, noninverting configuration, T A = T MIN to T MAX, unless otherwise noted. Typical values are at T A = + C.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Small-Signal -db Bandwidth BW SS V = mvp-p MHz Large-Signal -db Bandwidth BW LS V = Vp-p MHz Bandwidth for.db Gain Flatness BW.dB V = mvp-p (Note ) MHz Slew Rate SR V = V step V/µs Settling Time to.% t S V = V step ns Rise/Fall Time t R, t F V = mvp-p ns Spurious-Free Dynamic Range SFDR f C = MHz, V = Vp-p - dbc Second harmonic - Harmonic Distortion Third-Order Intercept Input db Compression Point Differential Phase Error Differential Gain Error Input Noise Voltage Density Input Noise Current Density Input Capacitance Disabled Output Capacitance Output Impedance Buffer Enable Time Buffer Disable Time Buffer Gain Matching Buffer Crosstalk HD IP DP DG e n i n C IN C (OFF) Z t ON t OFF X TALK V = Vp-p, f C = MHz f =.MHz dbm f C = MHz, A VCL = +V/V dbm NTSC, R L = Ω. degrees NTSC, R L = Ω. % f = khz nv/ Hz f = khz. pa/ Hz pf MAX9, EN_ = V pf f = MHz Ω MAX9 ns MAX9 µs MAX/MAX9/MAX, f = MHz, V = mvp-p MAX/MAX9/MAX, f = MHz, V = Vp-p Third harmonic Total harmonic distortion dbc db db MAX/MAX/MAX9/MAX Note : The MAXEUK is % production tested at T A = + C. Specifications over temperature limits are guaranteed by design. Note : Tested with V = +.V. Note : PSRR for single +V supply tested with V EE = V, V CC = +.V to +.V; for dual ±V supply with V EE = -.V to -.V, V CC = +.V to +.V; and for single +V supply with V EE = V, V CC = +.V to +.V. Note : Guaranteed by design.

4 Low-Cost, High-Speed, Single-Supply, Gain of + Buffers with Rail-to-Rail Outputs in SOT MAX/MAX/MAX9/MAX Typical Operating Characteristics (V CC = +V, V EE = V, A VCL = +, R L = Ω to V CC /, T A = + C, unless otherwise noted.) GAIN (db) CROSSTALK (db) SMALL-SIGNAL GAIN vs. FREQUENCY k M M M G MAX/9/ CROSSTALK vs. FREQUENCY - k M M M G HARMONIC DISTORTION (dbc) f = MHz V = Vp-p HARMONIC DISTORTION vs. LOAD rd HARMONIC rd HARMONIC LOAD (Ω) MAX- MAX- MAX- GAIN (db) IMPEDANCE (Ω) HARMONIC DISTORTION (dbc) GAIN FLATNESS vs. FREQUENCY.9 k M M M G CLOSED-LOOP PUT IMPEDANCE vs. FREQUENCY..M M M M f = MHz HARMONIC DISTORTION vs. PUT SWING RD HARMONIC ND HARMONIC.... PUT SWING (Vp-p) MAX- MAX- MAX- GAIN (db) HARMONIC DISTORTION (dbc) OFF ISOLATION (db) LARGE-SIGNAL GAIN vs. FREQUENCY k M M M G V = Vp-p HARMONIC DISTORTION vs. FREQUENCY ND HARMONIC RD HARMONIC - k M M M MAX9 OFF ISOLATION vs. FREQUENCY k M M M MAX- MAX- MAX-9

5 Low-Cost, High-Speed, Single-Supply, Gain of + Buffers with Rail-to-Rail Outputs in SOT Typical Operating Characteristics (V CC = +V, V EE = V, A VCL = +, R L = Ω to V CC /, T A = + C, unless otherwise noted.) POWER-SUPPLY REJECTION (db) PUT SWING (Vp-p) POWER-SUPPLY CURRENT (ma) POWER-SUPPLY REJECTION vs. FREQUENCY - k M M M POWER-SUPPLY CURRENT (PER AMPLIFIER) vs. TEMPERATURE PUT SWING vs. LOAD RESISTANCE k k k M LOAD RESISTANCE (Ω) MAX- MAX- MAX- NOISE (pa/ Hz) PUT SWING (Vp-p) INPUT BIAS CURRENT (µa) CURRENT NOISE DENSITY vs. FREQUENCY k k k M M PUT SWING vs. LOAD RESISTANCE (R L ) LOAD RESISTANCE (Ω) INPUT BIAS CURRENT vs. TEMPERATURE MAX- MAX- MAX- NOISE (nv/ Hz) BANDWIDTH (MHz) INPUT OFFSET CURRENT (µa)..... VOLTAGE NOISE DENSITY vs. FREQUENCY k k k M M BANDWIDTH vs. LOAD RESISTANCE LOAD RESISTANCE (Ω) INPUT OFFSET CURRENT vs. TEMPERATURE MAX- MAX- MAX- MAX/MAX/MAX9/MAX - - TEMPERATURE ( C). - - TEMPERATURE ( C) - - TEMPERATURE ( C)

6 Low-Cost, High-Speed, Single-Supply, Gain of + Buffers with Rail-to-Rail Outputs in SOT MAX/MAX/MAX9/MAX Typical Operating Characteristics (V CC = +V, V EE = V, A VCL = +, R L = Ω to V CC /, T A = + C, unless otherwise noted.) POWER-SUPPLY CURRENT (ma) DIFF. PHASE (deg) DIFF. GAIN (%) VOLTAGE (mv/div) POWER-SUPPLY CURRENT (PER AMPLIFIER) vs. POWER-SUPPLY VOLTAGE 9 POWER-SUPPLY VOLTAGE (V) DIFFERENTIAL GAIN AND PHASE IRE IN IRE LARGE-SIGNAL PULSE RESPONSE MAX- MAX-9 MAX- INPUT OFFSET VOLTAGE (mv) VOLTAGE (mv/div) VOLTAGE (mv/div) INPUT OFFSET VOLTAGE vs. TEMPERATURE - - TEMPERATURE ( C) IN IN SMALL-SIGNAL PULSE RESPONSE TIME (ns/div) V CM =.V, R L = Ω to GROUND LARGE-SIGNAL PULSE RESPONSE (C L = pf) MAX- MAX- MAX- VOLTAGE SWING (Vp-p) VOLTAGE (mv/div)..... VOLTAGE SWING vs. TEMPERATURE R L = Ω TO V CC /. - - TEMPERATURE ( C) IN EN_ SMALL-SIGNAL PULSE RESPONSE (C L = pf) TIME (ns/div) ENABLE RESPONSE TIME MAX- MAX- MAX-.V (ENABLE) V (DISABLE) V V TIME (ns/div) V CM =.9V, R L = Ω to GROUND TIME (ns/div) V CM =.V, R L = Ω to GROUND V IN =.V TIME (µs/div)

7 Low-Cost, High-Speed, Single-Supply, Gain of + Buffers with Rail-to-Rail Outputs in SOT Pin Description SOT- SO/µMAX SO 9 PIN MAX MAX MAX9 MAX QSOP, 9 SO 9 QSOP, 9 NAME N.C. V EE V CC A INA+ B INB+ C IND- INC- INC+ D INB- IN- INA- IND+ ENA No Connect. Not internally connected. Tie to ground or leave open. Amplifier Output Negative Power Supply or Ground (in single-supply operation) Noninverting Input Inverting Input Positive Power Supply Amplifier A Output Amplifier A Inverting Input Amplifier A Noninverting Input Amplifier B Output Amplifier B Inverting Input Amplifier B Noninverting Input Amplifier C Output Amplifier D Output FUNCTION Amplifier C Inverting Input Amplifier C Noninverting Input Amplifier D Inverting Input Amplifier D Noninverting Input Enable Input for Amplifier A MAX/MAX/MAX9/MAX ENB Enable Input for Amplifier B ENC Enable Input for Amplifier C

8 Low-Cost, High-Speed, Single-Supply, Gain of + Buffers with Rail-to-Rail Outputs in SOT MAX/MAX/MAX9/MAX Detailed Description The MAX/MAX/MAX9/MAX are single-supply, rail-to-rail output, voltage-feedback, closedloop buffers that employ current-feedback techniques to achieve V/µs slew rates and MHz bandwidths. These buffers use internal Ω resistors to provide a preset closed-loop gain of +V/V in the noninverting configuration or -V/V in the inverting configuration. Excellent harmonic distortion and differential gain/phase performance make these buffers an ideal choice for a wide variety of video and RF signal-processing applications. Local feedback around the buffer s output stage ensures low output impedance, which reduces gain sensitivity to load variations. This feedback also produces demand-driven current bias to the output transistors for ±ma drive capability, while constraining total supply current to less than ma. Applications Information Power Supplies These devices operate from a single +.V to +V power supply or from dual supplies of ±.V to ±.V. For single-supply operation, bypass the VCC pin to ground with a.µf capacitor as close to the pin as possible. If operating with dual supplies, bypass each supply with a.µf capacitor. Selecting Gain Configuration Each buffer in the MAX family can be configured for a voltage gain of +V/V or -V/V. For a gain of IN R TIN *R +V/V, ground the inverting terminal. Use the noninverting terminal as the signal input of the buffer (Figure a). Grounding the noninverting terminal and using the inverting terminal as the signal input configures the buffer for a gain of -V/V (Figure b). Since the inverting input exhibits a Ω input impedance, terminate the input with a Ω resistor when the device is configured for an inverting gain in Ω applications (terminate with Ω in Ω applications). Terminate the input with a 9.9Ω resistor in the noninverting case. Output terminating resistors should directly match cable impedances in either configuration. Layout Techniques Maxim recommends using microstrip and stripline techniques to obtain full bandwidth. To ensure that the PC board does not degrade the buffer s performance, design it for a frequency greater than GHz. Pay careful attention to inputs and outputs to avoid large parasitic capacitance. Whether or not you use a constant-impedance board, observe the following guidelines when designing the board: Don t use wire-wrapped boards. They are too inductive. Don t use IC sockets. They increase parasitic capacitance and inductance. Use surface-mount instead of through-hole components for better high-frequency performance. Use a PC board with at least two layers; it should be as free from voids as possible. Keep signal lines as short and as straight as possible. Do not make 9 turns; round all corners. R S *R *R *R Ω Ω MAX IN R TIN IN- IN- Ω Ω MAX *R L = R Figure a. Noninverting Gain Configuration (A V = +V/V) *R L = R Figure b. Inverting Gain Configuration (A V = -V/V)

9 Low-Cost, High-Speed, Single-Supply, Gain of + Buffers with Rail-to-Rail Outputs in SOT INPUT CURRENT (µa) V IL (mv ABOVE V EE ) Figure. Enable Logic-Low Input Current vs. Enable Logic- Low Threshold IN- Ω ENABLE MAX Ω Figure. Circuit to Reduce Enable Logic-Low Input Current Input Voltage Range and Output Swing The input range for the MAX family extends from (V EE - mv) to (V CC -.V). Input ground sensing increases the dynamic range for single-supply applications. The outputs drive a kω load to within mv of the power-suply rails. With heavier loads, the output swing is reduced as shown in the Electrical Characteristics and the Typical Operating Characteristics. As the load increases, the input range is effectively limited by k EN_ INPUT CURRENT (µa) V IL (mv ABOVE V EE ) Figure. Enable Logic-Low Input Current vs. Enable Logic- Low Threshold with kω Series Resistor the output-drive capability, since the buffers have a fixed voltage gain of + or -. For example, a Ω load can typically be driven from mv above V EE to.v below V CC, or mv to.v when operating from a single +V supply. If the buffer is operated in the noninverting, gain of + configuration with the inverting input grounded, the effective input voltage range becomes mv to.v, instead of the -mv to.v indicated by the Electrical Characteristics. Beyond the effective input range, the buffer output is a nonlinear function of the input, but it will not undergo phase reversal or latchup. Enable The MAX9 has an enable feature (EN_) that allows the buffer to be placed in a low-power state. When the buffers are disabled, the supply current will not exceed µa per buffer. As the voltage at the EN_ pin approaches the negative supply rail, the EN_ input current rises. Figure shows a graph of EN_ input current versus EN_ pin voltage. Figure shows the addition of an optional resistor in series with the EN pin, to limit the magnitude of the current increase. Figure displays the resulting EN pin input current to voltage relationship. MAX/MAX/MAX9/MAX 9

10 Low-Cost, High-Speed, Single-Supply, Gain of + Buffers with Rail-to-Rail Outputs in SOT MAX/MAX/MAX9/MAX IN- Ω Figure. Input Protection Circuit GIAN (db) C L = pf Ω k M M M C L = pf MAX MAX MAX9 MAX C L = pf Figure. Small-Signal Gain vs. Frequency with Load Capacitance and No Isolation Resistor Disabled Output Resistance The MAX/MAX/MAX9/MAX include internal protection circuitry that prevents damage to the precision input stage from large differential input voltages, as shown in Figure. This protection circuitry consists of five back-to-back Schottky diodes between IN_+ and IN_-. These diodes lower the disabled output resistance from kω to Ω when the output voltage is V greater or less than the voltage at IN_+. Under these G V IN R TIN Ω Ω Ω MAX conditions, the input protection diodes will be forward biased, lowering the disabled output resistance to Ω. Output Capacitive Loading and Stability The MAX/MAX/MAX9/MAX provide maximum AC performance with no load capacitance. This is the case when the load is a properly terminated transmission line. However, they are designed to drive up pf of load capacitance without oscillating, but with reduced AC performance. Driving large capacitive loads increases the chance of oscillations occurring in most amplifier circuits. This is especially true for circuits with high loop gains, such as voltage followers. The buffer s output resistance and the load capacitor combine to add a pole and excess phase to the loop response. If the frequency of this pole is low enough to interfere with the loop response and degrade phase margin sufficiently, oscillations can occur. A second problem when driving capacitive loads results from the amplifier s output impedance, which looks inductive at high frequencies. This inductance forms an L-C resonant circuit with the capacitive load, which causes peaking in the frequency response and degrades the amplifier s gain margin. Figure shows the frequency response of the MAX/ MAX/MAX9/MAX under different capacitive loads. To drive loads with greater than pf of capacitance or to settle out some of the peaking, the output requires an isolation resistor like the one shown in R ISO C L V Figure. Driving a Capacitive Load through an Isolation Resistor

11 Low-Cost, High-Speed, Single-Supply, Gain of + Buffers with Rail-to-Rail Outputs in SOT ISOLATION RESISTANCE, RISO (Ω) CAPACITIVE LOAD (pf) Figure. Capacitive Load vs. Isolation Resistance Figure. Figure is a graph of the optimal isolation resistor versus load capacitance. Figure 9 shows the frequency response of the MAX/MAX/MAX9/ MAX when driving capacitive loads with a Ω isolation resistor. GIAN (db) R ISO = Ω C L = pf C L = pf k M M M C L = pf Figure 9. Small-Signal Gain vs. Frequency with Load Capacitance and Ω Isolation Resistor Coaxial cables and other transmission lines are easily driven when properly terminated at both ends with their characteristic impedance. Driving back-terminated transmission lines essentially eliminates the lines capacitance. G MAX/MAX/MAX9/MAX

12 Low-Cost, High-Speed, Single-Supply, Gain of + Buffers with Rail-to-Rail Outputs in SOT MAX/MAX/MAX9/MAX Pin Configurations TOP VIEW V CC A V EE IN- V EE INB+ SOT- SO/µMAX V CC B INB- INA- MAX MAX INA+ ENA C A D ENC ENB V CC INA+ INA- A N.C. MAX9 9 INC- INC+ V EE INB+ INB- B N.C. INA- INA+ V CC INB+ INB- B MAX 9 IND- IND+ V EE INC+ INC- C SO QSOP Chip Information ENA C ENC ENB MAX9 INC- INC+ V CC V EE INA+ INB+ INA- A 9 INB- B SO A D INA- IND- INA+ IND+ V CC MAX V EE INB+ INC+ INB- INC- B C N.C. 9 N.C. QSOP PART NUMBER NO. OF TRANSISTORS MAX 9 MAX 9 MAX9 99 MAX SUBSTRATE CONNECTED TO VEE Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. Maxim Integrated Products, San Gabriel Drive, Sunnyvale, CA 9 -- Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.