Low Noise, Low Drift Single-Supply Operational Amplifiers OP113/OP213/OP413

Transcription

1 Low Noise, Low Drift Single-Supply Operational Amplifiers OP3/OP3/OP3 FEATURES Single- or dual-supply operation Low noise:.7 nv/ khz Wide bandwidth: 3. MHz Low offset voltage: μv Very low drift:. μv/ C Unity gain stable No phase reversal APPLICATIONS Digital scales Multimedia Strain gages Battery-powered instrumentation Temperature transducer amplifier GENERAL DESCRIPTION The OPx3 family of single-supply operational amplifiers features both low noise and drift. It has been designed for systems with internal calibration. Often these processor-based systems are capable of calibrating corrections for offset and gain, but they cannot correct for temperature drifts and noise. Optimized for these parameters, the OPx3 family can be used to take advantage of superior analog performance combined with digital correction. Many systems using internal calibration operate from unipolar supplies, usually either 5 V or V. The OPx3 family is designed to operate from single supplies from V to 36 V and to maintain its low noise and precision performance. The OPx3 family is unity gain stable and has a typical gain bandwidth product of 3. MHz. Slew rate is in excess of V/μs. Noise density is a very low.7 nv/ Hz, and noise in the. Hz to Hz band is nv p-p. Input offset voltage is guaranteed and offset drift is guaranteed to be less than. μv/ C. Input common-mode range includes the negative supply and to within V of the positive supply over the full supply range. Phase reversal protection is designed into the OPx3 family for cases where input voltage range is exceeded. Output voltage swings also include the negative supply and go to within V of the positive rail. The output is capable of sinking and sourcing current throughout its range and is specified with 6 Ω loads. NULL IN A IN A 3 V OP3 TOP VIEW (Not to Scale) PIN CONFIGURATIONS NC 7 V 6 OUT A 5 NULL NC = NO CONNECT Figure. -Lead Narrow-Body SOIC_N OUT A IN A IN A 3 V OP3 Figure 3. -Lead PDIP V 6- OUT B IN B IN B 6-3 OUT A IN A IN A 3 V OP3 TOP VIEW (Not to Scale) V 7 OUT B 6 IN B 5 IN B Figure. -Lead Narrow-Body SOIC_N OUT A 6 OUT D IN A 5 IN D IN A 3 OP3 IN D V TOP VIEW 3 V (Not to Scale) IN B 5 IN C IN B 6 IN C OUT B 7 OUT C NC 9 NC NC = NO CONNECT Figure. 6-Lead Wide-Body SOIC_W Digital scales and other strain gage applications benefit from the very low noise and low drift of the OPx3 family. Other applications include use as a buffer or amplifier for both analogto-digital (ADC) and digital-to-analog (DAC) sigma-delta converters. Often these converters have high resolutions requiring the lowest noise amplifier to utilize their full potential. Many of these converters operate in either singlesupply or low-supply voltage systems, and attaining the greater signal swing possible increases system performance. The OPx3 family is specified for single 5 V and dual ±5 V operation over the XIND extended industrial temperature range ( C to 5 C). They are available in PDIP and SOIC surface-mount packages Rev. F Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. Specifications subject to change without notice. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Trademarks and registered trademarks are the property of their respective owners. One Technology Way, P.O. Box 96, Norwood, MA 6-96, U.S.A. Tel: Fax: Analog Devices, Inc. All rights reserved.

2 TABLE OF CONTENTS Features... Applications... General Description... Pin Configurations... Revision History... Specifications... 3 Electrical Characteristics... 3 Absolute Maximum Ratings... 6 Thermal Resistance... 6 ESD Caution... 6 Typical Performance Characteristics... 7 Applications... 3 Phase Reversal... 3 OP3 Offset Adjust... 3 Application Circuits... A High Precision Industrial Load-Cell Scale Amplifier... A Low Voltage, Single Supply Strain Gage Amplifier... A High Accuracy Linearized RTD Thermometer Amplifier... A High Accuracy Thermocouple Amplifier... 5 An Ultralow Noise, Single Supply Instrumentation Amplifier... 5 Supply Splitter Circuit... 5 Low Noise Voltage Reference V Only Stereo DAC for Multimedia... 6 Low Voltage Headphone Amplifiers... 7 Low Noise Microphone Amplifier for Multimedia... 7 Precision Voltage Comparator... 7 Outline Dimensions... 9 Ordering Guide... REVISION HISTORY 3/7 Rev. E to Rev. F Updated Format...Universal Changes to Pin Configurations... Changes to Absolute Maximum Ratings Section... 6 Deleted Spice Model... 5 Updated Outline Dimensions... 9 Changes to Ordering Guide... / Rev. D to Rev. E Edits to Figure Edits to Figure Edits to OUTLINE DIMENSIONS / Rev. C to Rev. E Edits to ORDERING GUIDE... Rev. F Page of

3 SPECIFICATIONS ELECTRICAL VS = ±5. V, TA = 5 C, unless otherwise noted. Table. E Grade F Grade Parameter Symbol Conditions Min Typ Max Min Typ Max Unit INPUT CHARACTERISTICS Offset Voltage VOS OP μv C TA 5 C 5 5 μv OP3 5 μv C TA 5 C 5 35 μv OP μv C TA 5 C μv Input Bias Current IB VCM = V 6 6 na C TA 5 C 7 7 na Input Offset Current IOS VCM = V C TA 5 C 5 5 na Input Voltage Range VCM 5 5 V Common-Mode Rejection CMR 5 V VCM V 6 96 db 5 V VCM V, C TA 5 C db Large-Signal Voltage Gain AVO OP3, OP3, RL = 6 Ω, C TA 5 C. V/μV OP3, RL = kω, C TA 5 C. V/μV RL = kω, C TA 5 C V/μV Long-Term Offset Voltage VOS 5 3 μv Offset Voltage Drift ΔVOS/ΔT...5 μv/ C OUTPUT CHARACTERISTICS Output Voltage Swing High VOH RL = kω V RL = kω, C TA 5 C V Output Voltage Swing Low VOL RL = kω.5.5 V RL = kω, C TA 5 C.5.5 V Short-Circuit Limit ISC ± ± ma POWER SUPPLY Power Supply Rejection Ratio PSRR VS = ± V to ± V 3 db VS = ± V to ± V C TA 5 C 97 db Supply Current/Amplifier ISY VOUT = V, RL =, VS = ± V 3 3 ma C TA 5 C ma Supply Voltage Range VS ± ± V Rev. F Page 3 of

4 E Grade F Grade Parameter Symbol Conditions Min Typ Max Min Typ Max Unit AUDIO PERFORMANCE THD Noise VIN = 3 V rms, RL = kω, f = khz.9.9 % Voltage Noise Density en f = Hz 9 9 nv/ Hz f = khz.7.7 nv/ Hz Current Noise Density in f = khz.. pa/ Hz Voltage Noise en p-p. Hz to Hz nv p-p DYNAMIC PERFORMANCE Slew Rate SR RL = kω.... V/μs Gain Bandwidth Product GBP MHz Channel Separation VOUT = V p-p RL = kω, f = khz 5 5 db Settling Time ts to.%, V to V step 9 9 μs Long-term offset voltage is guaranteed by a hour life test performed on three independent lots at 5 C, with an LTPD of.3. Guaranteed specifications, based on characterization VS = 5. V, TA = 5 C, unless otherwise noted. Table. E Grade F Grade Parameter Symbol Conditions Min Typ Max Min Typ Max Unit INPUT CHARACTERISTICS Offset Voltage VOS OP μv C TA 5 C 75 5 μv OP3 5 3 μv C TA 5 C μv OP μv C TA 5 C 5 μv Input Bias Current IB VCM = V, VOUT = na C TA 5 C na Input Offset Current IOS VCM = V, VOUT = C TA 5 C 5 5 na Input Voltage Range VCM V Common-Mode Rejection CMR V VCM V db V VCM V, C TA 5 C 9 7 db Large-Signal Voltage Gain AVO OP3, OP3, RL = 6 Ω, kω,. V VOUT 3.9 V V/μV OP3, RL = 6, kω,. V VOUT 3.9 V V/μV Long-Term Offset Voltage VOS 35 μv Offset Voltage Drift VOS/ T...5 μv/ C Rev. F Page of

5 E Grade F Grade Parameter Symbol Conditions Min Typ Max Min Typ Max Unit OUTPUT CHARACTERISTICS Output Voltage Swing High VOH RL = 6 kω.. V RL = kω, C TA 5 C.. V RL = 6 Ω, C TA 5 C V Output Voltage Swing Low VOL RL = 6 Ω, C TA 5 C mv RL = kω, C TA 5 C mv Short-Circuit Limit ISC ±3 ±3 ma POWER SUPPLY Supply Current ISY VOUT =. V, no load ma ISY C TA 5 C ma AUDIO PERFORMANCE THD Noise VOUT = dbu, f = khz.. % Voltage Noise Density en f = Hz 9 9 nv/ Hz f = khz.7.7 nv/ Hz Current Noise Density in f = khz.5.5 pa/ Hz Voltage Noise en p-p. Hz to Hz nv p-p DYNAMIC PERFORMANCE Slew Rate SR RL = kω V/μs Gain Bandwidth Product GBP MHz Settling Time ts to.%, V step μs Long-term offset voltage is guaranteed by a hour life test performed on three independent lots at 5 C, with an LTPD of.3. Guaranteed specifications, based on characterization data. Rev. F Page 5 of

6 ABSOLUTE MAXIMUM RATINGS Table 3. Parameter Rating Supply Voltage ± V Input Voltage ± V Differential Input Voltage ± V Output Short-Circuit Duration to GND Indefinite Storage Temperature Range 65 C to 5 C Operating Temperature Range C to 5 C Junction Temperature Range 65 C to 5 C Lead Temperature Range (Soldering, 6 sec) 3 C THERMAL RESISTANCE Table. Thermal Resistance Package Type θja θjc Unit -Lead PDIP (P) 3 3 C/W -Lead SOIC_N (S) 5 3 C/W 6-Lead SOIC_W (S) 9 7 C/W ESD CAUTION Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. This is a stress rating only; functional operation of the device at these or any other conditions above those indicated in the operational section of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Rev. F Page 6 of

7 TYPICAL PERFORMANCE CHARACTERISTICS OP AMPS PLASTIC PACKAGE 5 OP3/OP3/OP3 C T A 5 C OP AMPS PLASTIC PACKAGE UNITS 6 UNITS INPUT OFFSET VOLTAGE, V OS (µv) Figure 5. OP3 Input Offset (VOS) ±5 V TCV OS (µv) Figure. OP3 Temperature Drift (TCVOS) ±5 V OP AMPS PLASTIC PACKAGE 5 C T A 5 C 96 OP AMPS PLASTIC PACKAGE 3 3 UNITS UNITS 6 6 INPUT OFFSET VOLTAGE, V OS (µv) Figure 6. OP3 Input Offset (VOS) ±5 V TCV OS (µv) Figure 9. OP3 Temperature Drift (TCVOS) ±5 V OP AMPS PLASTIC PACKAGE 6 5 C T A 5 C OP AMPS PLASTIC PACKAGE 3 UNITS UNITS INPUT OFFSET VOLTAGE, V OS (µv) TCV OS (µv) 6- Figure 7. OP3 Input Offset (VOS) ±5 V Figure. OP3 Temperature Drift (TCVOS) ±5 V Rev. F Page 7 of

8 5 INPUT BIAS CURRENT (na) V CM = V V S = 5V V CM =.5V 5 5 TEMPERATURE ( C) 75 V CM = V Figure. OP3 Input Bias Current vs. Temperature 6-5 INPUT BIAS CURRENT (na) V S = 5V TEMPERATURE ( C) Figure. OP3 Input Bias Current vs. Temperature V S = 5V SWING R L = kω POSITIVE OUTPUT SWING (V) SWING R L = kω SWING R L = 6Ω SWING R L = kω SWING R L = 6Ω TEMPERATURE ( C) NEGATIVE OUTPUT SWING (mv) 6- POSITIVE OUTPUT SWING (V) SWING R L = 6Ω 5 SWING R L = 6Ω 5 5 TEMPERATURE ( C) SWING R L = kω Figure. Output Swing vs. Temperature and 5 V Figure 5. Output Swing vs. Temperature and ±5 V 6 V S = 5V V O = 3.9V CHANNEL SEPARATION (db) 6 5 OPEN-LOOP GAIN (V/µV) 6 6 R L = kω R L = 6Ω k k k M M TEMPERATURE ( C) Figure 3. Channel Separation Figure 6. Open-Loop Gain vs. 5 V Rev. F Page of

9 .5 R L = kω V D = ±V 9 V O = ±V. OPEN-LOOP GAIN (V/µV) R L = kω R L = 6Ω OPEN-LOOP GAIN (V/µV) R L = kω R L = 6Ω TEMPERATURE ( C) 75 Figure 7. OP3 Open-Loop Gain vs. Temperature TEMPERATURE ( C) Figure. OP3 Open-Loop Gain vs. Temperature V = 5V V = V OPEN-LOOP GAIN (db) 6 PHASE GAIN θm = PHASE (Degrees) OPEN-LOOP GAIN (db) 6 PHASE GAIN θm = PHASE (Degrees) 5 k k k M M Figure. Open-Loop Gain, Phase vs. 5 V CLOSED-LOOP GAIN (db) 5 3 A V = A V = A V = V = 5V V = V k k k M M Figure 9. Closed-Loop Gain vs. 5 V k k k M M CLOSED-LOOP GAIN (db) 5 3 Figure. Open-Loop Gain, Phase vs. ±5 V A V = A V = A V = k k k M M Figure. Closed-Loop Gain vs. ±5 V Rev. F Page 9 of

10 7 V = 5V V = V PHASE MARGIN (Degrees) GBW θm 3 GAIN BANDWIDTH PRODUCT (MHz) PHASE MARGIN (Degrees) GBW θm 3 GAIN BANDWIDTH PRODUCT (MHz) TEMPERATURE ( C) Figure 3. Gain Bandwidth Product and Phase Margin vs. 5 V VOLTAGE NOISE DENSITY (nv/ Hz) k Figure. Voltage Noise Density vs. Frequency TEMPERATURE ( C) 75 5 Figure 6. Gain Bandwidth Product and Phase Margin vs. ±5 V CURRENT NOISE DENSITY (pa/ Hz) k Figure 7. Current Noise Density vs. Frequency V = 5V V = V COMMON-MODE REJECTION (db) 6 k k k M 6- COMMON-MODE REJECTION (db) 6 k k k 6-7 M Figure 5. Common-Mode Rejection vs. 5 V Figure. Common-Mode Rejection vs. ±5 V Rev. F Page of

11 POWER SUPPLY REJECTION (db) MAXIMUM OUTPUT SWING (V) k PSRR k PSRR k Figure 9. Power Supply Rejection vs. ±5 V V S = 5V R L = kω A VCL = k k k M M Figure 3. Maximum Output Swing vs. 5 V 6- M 6-9 IMPEDANCE (Ω) 3 k A V = k A V = k A V = Figure 3. Closed-Loop Output Impedance vs. ±5 V MAXIMUM OUTPUT SWING (V) R L = kω A VOL = k k k M M Figure 33. Maximum Output Swing vs. ±5 V 6-3 M 6-3 OVERSHOOT (%) V S = 5V R L = kω V IN = mv p-p A VCL = NEGATIVE EDGE POSITIVE EDGE OVERSHOOT (%) 6 6 R L = kω V IN = mv p-p A VCL = POSITIVE EDGE NEGATIVE EDGE 5 3 LOAD CAPACITANCE (pf) Figure 3. Small-Signal Overshoot vs. Load 5 V LOAD CAPACITANCE (pf) Figure 3. Small-Signal Overshoot vs. Load ±5 V Rev. F Page of

12 . V S = 5V.5V V OUT.V. V V OUT V SLEW RATE SLEW RATE (V/µs).5. SLEW RATE SLEW RATE SLEW RATE (V/µs).5. SLEW RATE TEMPERATURE ( C) TEMPERATURE ( C) Figure 35. Slew Rate vs. 5 V (.5 V VOUT. V) Figure 3. Slew Rate vs. ±5 V ( V VOUT. V) s 9 s % mv Figure 36. Input Voltage ±5 V ( nv/div) 6-35 % mv Figure 39. Input Voltage 5 V ( nv/div) Ω 99Ω.Hz TO Hz A V = A V = t OUT 6-36 SUPPLY CURRENT (ma) 3 V S = ±V V S = 5V TEMPERATURE ( C) Figure 37. Noise Test Diagram Figure. Supply Current vs. Temperature Rev. F Page of

13 APPLICATIONS The OP3, OP3, and OP3 form a new family of high performance amplifiers that feature precision performance in standard dual-supply configurations and, more importantly, maintain precision performance when a single power supply is used. In addition to accurate dc specifications, it is the lowest noise single-supply amplifier available with only.7 nv/ Hz typical noise density. Single-supply applications have special requirements due to the generally reduced dynamic range of the output signal. Singlesupply applications are often operated at voltages of 5 V or V, compared to dual-supply applications with supplies of ± V or ±5 V. This results in reduced output swings. Where a dualsupply application may often have V of signal output swing, single-supply applications are limited to, at most, the supply range and, more commonly, several volts below the supply. In order to attain the greatest swing, the single-supply output stage must swing closer to the supply rails than in dual-supply applications. The OPx3 family has a new patented output stage that allows the output to swing closer to ground, or the negative supply, than previous bipolar output stages. Previous op amps had outputs that could swing to within about mv of the negative supply in single-supply applications. However, the OPx3 family combines both a bipolar and a CMOS device in the output stage, enabling it to swing to within a few hundred μv of ground. When operating with reduced supply voltages, the input range is also reduced. This reduction in signal range results in reduced signal-to-noise ratio for any given amplifier. There are only two ways to improve this: increase the signal range or reduce the noise. The OPx3 family addresses both of these parameters. Input signal range is from the negative supply to within V of the positive supply over the full supply range. Competitive parts have input ranges that are.5 V to 5 V less than this. Noise has also been optimized in the OPx3 family. At.7 nv/ Hz, the noise is less than one fourth that of competitive devices. PHASE REVERSAL The OPx3 family is protected against phase reversal as long as both of the inputs are within the supply ranges. However, if there is a possibility of either input going below the negative supply (or ground in the single-supply case), the inputs should be protected with a series resistor to limit input current to ma. OP3 OFFSET ADJUST The OP3 has the facility for external offset adjustment, using the industry standard arrangement. Pin and Pin 5 are used in conjunction with a potentiometer of kω total resistance, connected with the wiper to V (or ground in single-supply applications). The total adjustment range is about ± mv using this configuration. Adjusting the offset to has minimal effect on offset drift (assuming the potentiometer has a tempco of less than ppm/ C). Adjustment away from, however, (as with all bipolar amplifiers) results in a TCVOS of approximately 3.3 μv/ C for every millivolt of induced offset. It is, therefore, not generally recommended that this trim be used to compensate for system errors originating outside of the OP3. The initial offset of the OP3 is low enough that external trimming is almost never required, but if necessary, the mv trim range may be somewhat excessive. Reducing the trimming potentiometer to a kω value results in a more reasonable range of ± μv. Rev. F Page 3 of

14 APPLICATION CIRCUITS A HIGH PRECISION INDUSTRIAL LOAD-CELL SCALE AMPLIFIER The OPx3 family makes an excellent amplifier for conditioning a load-cell bridge. Its low noise greatly improves the signal resolution, allowing the load cell to operate with a smaller output range, thus reducing its nonlinearity. Figure shows one half of the OPx3 family used to generate a very stable V bridge excitation voltage while the second amplifier provides a differential gain. R should be trimmed for maximum common-mode rejection. N9A 35Ω LOAD CELL R5 kω 3 A / OP3 V mv F.S. R3 7.kΩ.% V 6 A 7 5 / OP3 5V R 7.kΩ.% R 5Ω R 3Ω.% 5V AD5BQ 5V µf CMRR TRIM -TURN T.C. LESS THAN 5ppm/ C OUTPUT V FS Figure. Precision Load-Cell Scale Amplifier A LOW VOLTAGE, SINGLE SUPPLY STRAIN GAGE AMPLIFIER The true zero swing capability of the OPx3 family allows the amplifier in Figure to amplify the strain gage bridge accurately even with no signal input while being powered by a single 5 V supply. A stable V bridge voltage is made possible by the rail-to-rail OP95 amplifier, whose output can swing to within a millivolt of either rail. This high voltage swing greatly increases the bridge output signal without a corresponding increase in bridge input. 6-35Ω 35mV FS NA V 5V 3 / OP95 3 / OP3 R kω R kω R kω R5.kΩ.5V R3 kω R6 7.Ω R G = 7.Ω R7 kω IN 6 OUT REF3 GND 5V 5 / OP95 6 R kω Figure. Single Supply Strain Gage Amplifier 7 OUTPUT V 3.5V A HIGH ACCURACY LINEARIZED RTD THERMOMETER AMPLIFIER Zero suppressing the bridge facilitates simple linearization of the resistor temperature device (RTD) by feeding back a small amount of the output signal to the RTD. In Figure 3, the left leg of the bridge is servoed to a virtual ground voltage by Amplifier A, and the right leg of the bridge is servoed to V by Amplifier A. This eliminates any error resulting from common-mode voltage change in the amplifier. A 3-wire RTD is used to balance the wire resistance on both legs of the bridge, thereby reducing temperature mismatch errors. The 5 V bridge excitation is derived from the extremely stable AD5 reference device with.5 ppm/ C drift performance. Linearization of the RTD is done by feeding a fraction of the output voltage back to the RTD in the form of a current. With just the right amount of positive feedback, the amplifier output will be linearly proportional to the temperature of the RTD. 6- Rev. F Page of

15 3 AD5BQ 5 6 5V 5V µf Ω RTD 3 R W R W R W3 R3 5Ω R.5kΩ R.5kΩ R Ω A 3 / OP3 R G FULL SCALE ADJUST R5.kΩ 5V 6 A 5 5V R7 Ω 7 / OP3 R 9.9kΩ Figure 3. Ultraprecision RTD Amplifier V OUT (mv/ C).5V = 5 C 5V = 5 C R9 5kΩ LINEARITY FS To calibrate the circuit, first immerse the RTD in a C ice bath or substitute an exact Ω resistor in place of the RTD. Adjust the zero adjust potentiometer for a V output, and then set R9, linearity adjust potentiometer, to the middle of its adjustment range. Substitute a.9 Ω resistor (equivalent to 5 C) in place of the RTD, and adjust the full-scale adjust potentiometer for a full-scale voltage of 5 V. To calibrate out the nonlinearity, substitute a 9.7 Ω resistor (equivalent to 5 C) in place of the RTD, and then adjust the linearity adjust potentiometer for a.5 V output. Check and readjust the full-scale and half-scale as needed. Once calibrated, the amplifier outputs a mv/ C temperature coefficient with an accuracy better than ±.5 C over an RTD measurement range of 5 C to 5 C. Indeed the amplifier can be calibrated to a higher temperature range, up to 5 C. A HIGH ACCURACY THERMOCOUPLE AMPLIFIER Figure shows a popular K-type thermocouple amplifier with cold-junction compensation. Operating from a single V supply, the OPx3 family s low noise allows temperature measurement to better than. C resolution over a C to C range. The cold-junction error is corrected by using an inexpensive silicon diode as a temperature measuring device. It should be placed as close to the two terminating junctions as physically possible. An aluminum block might serve well as an isothermal system. 6- K-TYPE THERMOCOUPLE.7µV/ C V REFEZ 6.µF N D R 5.6kΩ 5V R.7kΩ R.7kΩ R6 Ω R3 53.6Ω R5.kΩ R 53Ω R9 kω V µf.µf / OP3 3 V TO V ( C TO C) Figure. Accurate K-Type Thermocouple Amplifier R6 should be adjusted for a V output with the thermocouple measuring tip immersed in a C ice bath. When calibrating, be sure to adjust R6 initially to cause the output to swing in the positive direction first. Then back off in the negative direction until the output just stops changing. AN ULTRALOW NOISE, SINGLE SUPPLY INSTRUMENTATION AMPLIFIER Extremely low noise instrumentation amplifiers can be built using the OPx3 family. Such an amplifier that operates from a single supply is shown in Figure 5. Resistors R to R5 should be of high precision and low drift type to maximize CMRR performance. Although the two inputs are capable of operating to V, the gain of configuration limits the amplifier input common-mode voltage to.33 V. V IN *R kω / OP3 *R kω *ALL RESISTORS ±.%, ±5ppm/ C. *R3 kω *R G (Ω.7Ω) 5V TO 36V / OP3 *R kω V OUT kω GAIN = 6 R G Figure 5. Ultralow Noise, Single Supply Instrumentation Amplifier SUPPLY SPLITTER CIRCUIT The OPx3 family has excellent frequency response characteristics that make it an ideal pseudoground reference generator, as shown in Figure 6. The OPx3 family serves as a voltage follower buffer. In addition, it drives a large capacitor that serves as a charge reservoir to minimize transient load changes, as well as a low impedance output device at high frequencies. The circuit easily supplies 5 ma load current with good settling characteristics Rev. F Page 5 of

16 OP3/OP3/OP3 V S = 5V V R 5kΩ R 5kΩ 3 / OP3 C.µF R3.5kΩ R Ω Figure 6. False Ground Generator C µf V S OUTPUT LOW NOISE VOLTAGE REFERENCE Few reference devices combine low noise and high output drive capabilities. Figure 7 shows the OPx3 family used as a twopole active filter that band limits the noise of the.5 V reference. Total noise measures 3 μv p-p V IN OUT 6 REF3 GND µf kω kω 3 C µf 5V / OP3 Figure 7. Low Noise Voltage Reference 3µV p-p NOISE OUTPUT.5V 5 V ONLY STEREO DAC FOR MULTIMEDIA The OPx3 family s low noise and single supply capability are ideally suited for stereo DAC audio reproduction or sound synthesis applications such as multimedia systems. Figure shows an -bit stereo DAC output setup that is powered from a single 5 V supply. The low noise preserves the -bit dynamic range of the AD6. For DACs that operate on dual supplies, the OPx3 family can also be powered from the same supplies V SUPPLY V L LL DL CK DR LR -BIT DAC -BIT SERIAL REG. -BIT SERIAL REG. AD6 V REF V REF V B L V O L AGND kΩ 33pF 9.76kΩ 3 / OP3 7.6kΩ 7.6kΩ pf µf LEFT CHANNEL OUTPUT 7kΩ 7 DGND -BIT DAC V B R V O R V S 9 7.6kΩ 33pF 9.76kΩ 6 5 / OP3 Figure. 5 V Only -Bit Stereo DAC pf 7 µf RIGHT CHANNEL OUTPUT 7kΩ 6-7 Rev. F Page 6 of

17 LOW VOLTAGE HEADPHONE AMPLIFIERS Figure 9 shows a stereo headphone output amplifier for the AD9 6-bit SOUNDPORT stereo codec device. The pseudo-reference voltage is derived from the common-mode voltage generated internally by the AD9, thus providing a convenient bias for the headphone output amplifiers. µf LOUTL 3 AD9 CMOUT 9 V REF OPTIONAL GAIN kω V REF kω L VOLUME CONTROL 5kΩ 5V / OP3 5V / OP3 kω / OP3 LOUTR 9 µf R VOLUME CONTROL kω 5kΩ OPTIONAL GAIN V REF 6Ω µf 7kΩ µf 6Ω 7kΩ HEADPHONE LEFT HEADPHONE RIGHT Figure 9. Headphone Output Amplifier for Multimedia Sound Codec LOW NOISE MICROPHONE AMPLIFIER FOR MULTIMEDIA The OPx3 family is ideally suited as a low noise microphone preamp for low voltage audio applications. Figure 5 shows a gain of stereo preamp for the AD9 6-bit SOUNDPORT stereo codec chip. The common-mode output buffer serves as a phantom power driver for the microphones. 6- LEFT ELECTRET CONDENSER MIC INPUT RIGHT ELECTRET CONDENSER MIC INPUT Ω Ω µf 5V 5Ω / OP3 µf kω kω 5Ω Ω Ω kω kω 5V / OP3 / OP3 7 MINL AD9 9 CMOUT 5 MINR Figure 5. Low Noise Stereo Microphone Amplifier for Multimedia Sound Codec PRECISION VOLTAGE COMPARATOR With its PNP inputs and V common-mode capability, the OPx3 family can make useful voltage comparators. There is only a slight penalty in speed in comparison to IC comparators. However, the significant advantage is its voltage accuracy. For example, VOS can be a few hundred microvolts or less, combined with CMRR and PSRR exceeding db, while operating from a 5 V supply. Standard comparators like the /3 family operate on 5 V, but not with common mode at ground, nor with offset below 3 mv. Indeed, no commercially available singlesupply comparator has a VOS less than μv. SOUNDPORT is a registered trademark of Analog Devices, Inc. 6-9 Rev. F Page 7 of

18 Figure 5 shows the OPx3 family response to a mv overdrive signal when operating in open loop. The top trace shows the output rising edge has a 5 μs propagation delay, whereas the bottom trace shows a 7 μs delay on the output falling edge. This ac response is quite acceptable in many applications. The low noise and 5 μv (maximum) offset voltage enhance the overall dc accuracy of this type of comparator. Note that zerocrossing detectors and similar ground referred comparisons can be implemented even if the input swings to.3 V below ground..5v V.5V t r = t f = 5ms ±mv OVERDRIVE 5kΩ Ω 5V / OP3 IN IN 9V 9V OUT V 5µs 9 % Figure 5. OP3 Simplified Schematic 6-5 V Figure 5. Precision Comparator 6-5 Rev. F Page of

19 OUTLINE DIMENSIONS. (.6).365 (9.7).355 (9.). (5.33) MAX.5 (3.).3 (3.3).5 (.9). (.56). (.6). (.36). (.5) BSC 5. (7.).5 (6.35). (6.).5 (.3) MIN SEATING PLANE.5 (.3) MIN.6 (.5) MAX.5 (.3) GAUGE PLANE.35 (.6).3 (7.7).3 (7.6).3 (.9) MAX.95 (.95).3 (3.3).5 (.9). (.36). (.5). (.).7 (.7).6 (.5).5 (.) COMPLIANT TO JEDEC STANDARDS MS- CONTROLLING DIMENSIONS ARE IN INCHES; MILLIMETER DIMENSIONS (IN PARENTHESES) ARE ROUNDED-OFF INCH EQUIVALENTS FOR REFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN. CORNER LEADS MAY BE CONFIGURED AS WHOLE OR HALF LEADS. Figure 53. -Lead Plastic Dual In-Line Package [PDIP] Narrow Body P-Suffix (N-) Dimensions shown in inches and (millimeters) 766-A 5. (.96). (.9). (.57) 3. (.97) 5 6. (.) 5. (.).5 (.9). (.) COPLANARITY. SEATING PLANE.7 (.5) BSC.75 (.6).35 (.53).5 (.).3 (.).5 (.9).7 (.67).5 (.96).5 (.99).7 (.5). (.57) 5 COMPLIANT TO JEDEC STANDARDS MS--AA CONTROLLING DIMENSIONS ARE IN MILLIMETERS; INCH DIMENSIONS (IN PARENTHESES) ARE ROUNDED-OFF MILLIMETER EQUIVALENTS FOR REFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN. Figure 5. -Lead Standard Small Outline Package [SOIC_N] Narrow Body S-Suffix (R-) Dimensions shown in millimeters and (inches) 7-A Rev. F Page 9 of

20 .5 (.3). (.3976) (.99) 7. (.93).65 (.93). (.3937).3 (.). (.39) COPLANARITY.7 (.5) BSC.65 (.3).35 (.95)..5 (.) SEATING PLANE.33 (.3).3 (.). (.79).75 (.95).5 (.9) 5.7 (.5). (.57) COMPLIANT TO JEDEC STANDARDS MS-3-AA CONTROLLING DIMENSIONS ARE IN MILLIMETERS; INCH DIMENSIONS (IN PARENTHESES) ARE ROUNDED-OFF MILLIMETER EQUIVALENTS FOR REFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN. Figure Lead Standard Small Outline Package [SOIC_W] Wide Body S-Suffix (RW-6) Dimensions shown in millimeters and (inches) 377-B ORDERING GUIDE Model Temperature Range Package Description Package Options OP3ES C to 5 C -Lead SOIC_N R- (S-Suffix) OP3ES-REEL C to 5 C -Lead SOIC_N R- (S-Suffix) OP3ES-REEL7 C to 5 C -Lead SOIC_N R- (S-Suffix) OP3ESZ C to 5 C -Lead SOIC_N R- (S-Suffix) OP3ESZ-REEL C to 5 C -Lead SOIC_N R- (S-Suffix) OP3ESZ-REEL7 C to 5 C -Lead SOIC_N R- (S-Suffix) OP3FS C to 5 C -Lead SOIC_N R- (S-Suffix) OP3FS-REEL C to 5 C -Lead SOIC_N R- (S-Suffix) OP3FS-REEL7 C to 5 C -Lead SOIC_N R- (S-Suffix) OP3FSZ C to 5 C -Lead SOIC_N R- (S-Suffix) OP3FSZ-REEL C to 5 C -Lead SOIC_N R- (S-Suffix) OP3FSZ-REEL7 C to 5 C -Lead SOIC_N R- (S-Suffix) OP3ES C to 5 C -Lead SOIC_N R- (S-Suffix) OP3ES-REEL C to 5 C -Lead SOIC_N R- (S-Suffix) OP3ES-REEL7 C to 5 C -Lead SOIC_N R- (S-Suffix) OP3ESZ C to 5 C -Lead SOIC_N R- (S-Suffix) OP3ESZ-REEL C to 5 C -Lead SOIC_N R- (S-Suffix) OP3ESZ-REEL7 C to 5 C -Lead SOIC_N R- (S-Suffix) OP3FP C to 5 C -Lead PDIP N- (P-Suffix) OP3FPZ C to 5 C -Lead PDIP N- (P-Suffix) OP3FS C to 5 C -Lead SOIC_N R- (S-Suffix) OP3FS-REEL C to 5 C -Lead SOIC_N R- (S-Suffix) OP3FS-REEL7 C to 5 C -Lead SOIC_N R- (S-Suffix) OP3FSZ C to 5 C -Lead SOIC_N R- (S-Suffix) OP3FSZ-REEL C to 5 C -Lead SOIC_N R- (S-Suffix) OP3FSZ-REEL7 C to 5 C -Lead SOIC_N R- (S-Suffix) Rev. F Page of

21 Model Temperature Range Package Description Package Options OP3ES C to 5 C 6-Lead Wide Body SOIC_W RW-6 (S-Suffix) OP3ES-REEL C to 5 C 6-Lead Wide Body SOIC_W RW-6 (S-Suffix) OP3ESZ C to 5 C 6-Lead Wide Body SOIC_W RW-6 (S-Suffix) OP3ESZ-REEL C to 5 C 6-Lead Wide Body SOIC_W RW-6 (S-Suffix) OP3FS C to 5 C 6-Lead Wide Body SOIC_W RW-6 (S-Suffix) OP3FS-REEL C to 5 C 6-Lead Wide Body SOIC_W RW-6 (S-Suffix) OP3FSZ C to 5 C 6-Lead Wide Body SOIC_W RW-6 (S-Suffix) OP3FSZ-REEL C to 5 C 6-Lead Wide Body SOIC_W RW-6 (S-Suffix) Z = RoHS Compliant Part. Rev. F Page of

22 NOTES Rev. F Page of

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24 NOTES 9937 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. C6--3/7(F) Rev. F Page of