AD8675

36 V Precision, 2.8 nV/√Hz Rail-to-Rail Output Op Amp AD8675 FEATURES Very low voltage noise: 2.8 nV/√Hz Rail-to-rail output swing Low input bias current: 2 nA maximum Very low offset voltage: 75 μV maximum Low input offset drift: 0.6 μV/°C maximum Very high gain: 120 dB Wide bandwidth: 10 MHz typical ±5 V to ±18 V operation PIN CONFIGURATIONS NULL 1 –IN 2 +IN 3 8 NULL V+ AD8675 7 NC = NO CONNECT Figure 1. 8-Lead SOIC_N (R-8) NULL 1 –IN 2 +IN 3 V– 4 8 APPLICATIONS Precision instrumentation PLL filters Laser diode control loops Strain gage amplifiers Medical instrumentation Thermocouple amplifiers AD8675 TOP VIEW (Not to Scale) NULL V+ OUT 05564-002 7 6 5 NC NC = NO CONNECT Figure 2. 8-Lead MSOP (RM-8) GENERAL DESCRIPTION The AD8675 precision operational amplifier has ultralow offset, drift, and voltage noise combined with very low input bias currents over the full operating temperature range. The AD8675 is a precision, wide bandwidth op amp featuring rail-to-rail output swings and very low noise. Operation is fully specified from ±5 V to ±15 V. The AD8675 features a rail-to-rail output like that of the OP184, but with wide bandwidth and even lower voltage noise, combined with the precision and low power consumption like that of the industry-standard OP07 amplifier. Unlike other low noise, rail-to-rail op amps, the AD8675 has very low input bias current and low input current noise. With typical offset voltage of only 10 μV, offset drift of 0.2 μV/°C, and noise of only 0.10 μV p-p (0.1 Hz to 10 Hz), the AD8675 is perfectly suited for applications where large error sources cannot be tolerated. For applications with even lower offset tolerances, the proprietary nulling capability allows a combination of both device and system offset errors up to 3.5 mV (referred to the input) to be compensated externally. Unlike previous circuits, the AD8675 accommodates this adjustment without adversely affecting the offset drift, CMRR, and PSRR of the amplifier. Precision instrumentation, PLL, and other precision filter circuits, position and pressure sensors, medical instrumentation, and strain gage amplifiers benefit greatly from the very low noise, low input bias current, and wide bandwidth. Many systems can take advantage of the low noise, dc precision, and rail-to-rail output swing provided by the AD8675 to maximize SNR and dynamic range. The smaller packages and low power consumption afforded by the AD8675 allow maximum channel density or minimum board size for space-critical equipment. The AD8675 is specified for the extended industrial temperature range (−40°C to +125°C). The AD8675 amplifier is available in the tiny 8-lead MSOP, and the popular 8-lead, narrow SOIC, RoHS compliant packages. MSOP packaged devices are only available in tape and reel format. Rev. A 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 9106, Norwood, MA 02062-9106, U.S.A. Tel: 781.329.4700 www.analog.com Fax: 781.461.3113 ©2005-2007 Analog Devices, Inc. All rights reserved. 05564-001 6 OUT TOP VIEW (Not to Scale) V– 4 5 NC AD8675 TABLE OF CONTENTS Features .............................................................................................. 1 Applications....................................................................................... 1 Pin Configurations ........................................................................... 1 General Description ......................................................................... 1 Revision History ............................................................................... 2 Specifications..................................................................................... 3 Electrical Specifications............................................................... 3 Absolute Maximum Ratings ............................................................5 Thermal Resistance .......................................................................5 ESD Caution...................................................................................5 Typical Performance Characteristics ..............................................6 Outline Dimensions ....................................................................... 11 Ordering Guide .......................................................................... 11 REVISION HISTORY 4/07—Rev. 0 to Rev. A Inserted Figure 7 and Figure 8; renumbered sequentially ................................................................. 6 10/05—Revision 0: Initial Version Rev. A | Page 2 of 12 AD8675 SPECIFICATIONS ELECTRICAL SPECIFICATIONS VS = ±5.0 V, VCM = 0 V, VO = 0 V, TA = +25°C, unless otherwise specified. Table 1. Parameter INPUT CHARACTERISTICS Offset Voltage Input Bias Current Input Offset Current Input Voltage Range Common-Mode Rejection Ratio Open-Loop Gain Symbol VOS −40°C ≤ TA ≤ +125°C IB −40°C ≤ TA ≤ +125°C IOS −40°C ≤ TA ≤ +125°C CMRR AVO VCM = −3.5 V to +3.5 V −40°C ≤ TA ≤ +125°C RL = 2 kΩ to ground, VO = −4.0 V to +4.0 V −40°C ≤ TA ≤ +125°C −40°C ≤ TA ≤ +125°C RL = 2 kΩ to ground −40°C ≤ TA ≤ +125°C RL = 2 kΩ to ground −40°C ≤ TA ≤ +125°C −2 −5.5 −1 −2.8 −3.5 105 105 1000 700 Conditions Min Typ 10 12 0.5 −2 0.1 0.1 130 130 2000 1250 0.2 4.90 4.85 −4.91 −4.91 40 ±20 140 140 2.3 2.7 2.5 10 0.1 2.8 0.3 Max 75 240 2 5.5 1 2.8 3.5 Unit μV nA nA nA nA V dB dB V/mV V/mV μV/°C V V V V mA mA dB dB mA mA V/μs MHz μV p-p nV/√Hz pA/√Hz Offset Voltage Drift OUTPUT CHARACTERISTICS Output Voltage High Output Voltage Low Short-Circuit Limit Output Current POWER SUPPLY Power Supply Rejection Ratio Supply Current/Amplifier DYNAMIC PERFORMANCE Slew Rate Gain Bandwidth Product NOISE PERFORMANCE Voltage Noise Voltage Noise Density Current Noise Density ΔVOS/ΔT VOH VOL ISC IO PSRR ISY 0.6 4.86 4.82 −4.86 −4.82 VS = ±5.0 V to ±15.0 V −40°C ≤ TA ≤ +125°C VO = 0 V −40°C ≤ TA ≤ +125°C RL = 2 kΩ 120 120 2.7 3.4 SR GBP en p-p en in 0.1 Hz to 10 Hz f = 1 kHz f = 10 Hz Rev. A | Page 3 of 12 AD8675 VS = ±15 V, VCM = 0 V, VO = 0 V, TA = +25°C, unless otherwise specified. Table 2. Parameter INPUT CHARACTERISTICS Offset Voltage Input Bias Current Input Offset Current Input Voltage Range Common-Mode Rejection Ratio Open-Loop Gain Symbol VOS −40°C ≤ TA ≤ +125°C IB −40°C ≤ TA ≤ +125°C IOS −40°C ≤ TA ≤ +125°C CMRR AVO VCM = −12.5 V to +12.5 V −40°C ≤ TA ≤ +125°C RL = 2 kΩ to ground, VO = −14.0 V to +14.0 V −40°C ≤ TA ≤ +125°C −40°C ≤ TA ≤ +125°C SOIC RL: 2 kΩ to ground MSOP RL: 2 kΩ to ground SOIC −40°C ≤ TA ≤ +125°C MSOP −40°C ≤ TA ≤ +125°C RL = 2 kΩ to ground −40°C ≤ TA ≤ +125°C −2 −4.5 −1 −2.8 −13.5 114 114 1500 700 Conditions Min Typ 10 12 0.5 1 0.1 0.1 130 130 4000 1700 0.2 14.8 14.78 14.75 14.66 −14.85 −14.78 40 ±20 140 140 2.5 2.9 2.5 10 0.1 2.8 0.3 Max 75 240 2 4.5 1 2.8 13.5 Units μV nA nA nA nA V dB dB V/mV V/mV μV/°C V V V V V V mA mA dB dB mA mA V/μs MHz μV p-p nV/√Hz pA/√Hz Offset Voltage Drift OUTPUT CHARACTERISTICS Output Voltage High ΔVOS/ΔT VOH 0.6 14.75 14.67 14.69 14.3 Output Voltage Low Short-Circuit Limit Output Current POWER SUPPLY Power Supply Rejection Ratio Supply Current/Amplifier DYNAMIC PERFORMANCE Slew Rate Gain Bandwidth Product NOISE PERFORMANCE Voltage Noise Voltage Noise Density Current Noise Density VOL ISC IO PSRR ISY −14.75 −14.69 VS = ±5.0 V to ±15.0 V −40°C ≤ TA ≤ +125°C VO = 0 V −40°C ≤ TA ≤ +125°C RL =10 kΩ 120 120 2.9 3.8 SR GBP en p-p en in 0.1 Hz to 10 Hz f = 1 kHz f = 10 Hz Rev. A | Page 4 of 12 AD8675 ABSOLUTE MAXIMUM RATINGS Table 3. Parameter Supply Voltage Input Voltage Differential Input Voltage Output Short-Circuit Duration to GND Storage Temperature Range RM-8, R-8 Packages Operating Temperature Range Junction Temperature Range RM-8, R-8 Packages Lead Temperature Range (Soldering, 10 sec) Rating ±18 V ±V supply ±0.7 V Indefinite −65°C to +150°C −40°C to +125°C −65°C to +150°C 300°C THERMAL RESISTANCE Table 4. Thermal Resistance Package Type 8-Lead MSOP (RM-8) 8-Lead SOIC_N (R-8) θJA 210 158 θJC 45 43 Unit °C/W °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. A | Page 5 of 12 AD8675 TYPICAL PERFORMANCE CHARACTERISTICS ±15 V and ±5 V, TA = 25°C, unless otherwise specified. 10 9 150 100 VOLTAGE NOISE DENSITY (nV/ Hz) 8 OFFSET VOLTAGE (µV) 1 10 100 1k 10k 100k 05564-011 7 6 5 4 3 2 1 0 50 0 –50 –100 –150 –200 –40 25 TEMPERATURE (°C) 125 FREQUENCY (Hz) Figure 3. Voltage Noise Density vs. Frequency 50 45 40 100 120 Figure 6. Offset Voltage vs. Temperature VS = ±15V TA = 25°C NUMBER OF AMPLIFIERS 35 30 25 20 15 10 5 NUMBER OF AMPLIFIERS 80 60 40 20 0.05 0.15 0.25 0.35 0.45 0.55 –0.65 –0.55 –0.45 –0.35 –0.25 –0.15 –0.05 0.65 0.65 0 0 0 –5 5 10 15 20 25 30 35 40 45 –30 –25 –20 –15 –10 50 OFFSET VOLTAGE (µV) 05564-016 IB (nA) Figure 4. Input Offset Voltage Distribution 25 160 140 Figure 7. Input Bias Current, VS = ±15 V VS = ±5V TA = 25°C 20 NUMBER OF AMPLIFIERS NUMBER OF AMPLIFIERS 120 100 80 60 40 20 15 10 5 0.05 0.15 0.25 0.35 0.45 –0.65 –0.55 –0.45 –0.35 –0.25 –0.15 –0.05 0 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45 0.50 0.55 0.60 0.65 0.70 0.75 0.80 0.85 0.90 0.95 1.00 0.55 0 05564-014 0 05564-008 TCVOS (µV/°C) IB (nA) Figure 5. TCVOS Rev. A | Page 6 of 12 Figure 8. Input Bias Current, VS = ±5 V 05564-006 05564-005 AD8675 5 4 3 2 1 VS = ±5V GAIN (dB) 120 100 80 60 40 20 0 –20 –40 –60 –80 –100 1k 10k 100k 1M 10M 05564-018 180 GAIN RL = 2kΩ CL = 35pF θM = 55.2 120 PHASE 60 0 –1 –2 –3 –4 –20 0 20 40 60 80 100 120 05564-007 0 VS = ±15V –60 –120 –120 100 –180 100M –5 –40 FREQUENCY (Hz) TEMPERATURE (°C) Figure 9. Input Bias Current vs. Temperature 3.0 60 50 Figure 12. Gain and Phase vs. Frequency 2.5 CLOSED-LOOP GAIN (dB) 40 G = 100 30 20 10 0 –10 –20 –30 05564-009 SUPPLY CURRENT (mA) 2.0 G = 10 1.5 1.0 G=1 0.5 5 10 15 20 25 30 35 10k 100k 1M 10M 100M SUPPLY VOLTAGE (V) FREQUENCY (Hz) Figure 10. Supply Current vs. Total Supply Voltage 3.5 3.0 VS = ±15V 2.5 ZOUT (Ω) 70 60 50 40 30 20 Figure 13. Closed-Loop Gain vs. Frequency ISY (mA) 2.0 1.5 1.0 0.5 0 –40 VS = ±5V AVO = 100 AVO = 10 AVO = 1 10 0 1k –20 0 20 40 60 80 100 120 05564-019 10k 100k 1M 10M 100M TEMPERATURE (°C) FREQUENCY (Hz) Figure 11. Supply Current vs. Temperature Figure 14. ZOUT vs. Frequency Rev. A | Page 7 of 12 05564-015 05564-030 0 –40 1k PHASE MARGIN (Degrees) IB (nA) AD8675 15 0.1 50 VIN 40 30 20 10 –0 VOUT –0.5 –0.6 –0.7 –4 05564-020 10 VIN = ±11V RL = 2kΩ AV = +1 0 –0.1 5 VOLTAGE (V) –0.2 –0.3 –0.4 0 –5 –10 VIN = 200mV p-p AVO = –100 RL = 10kΩ 1 6 11 16 TIME (µs) 21 26 31 –20 –30 36 –10 OUTPUT VOLTAGE (V) OUTPUT VOLTAGE (V) 05564-029 05564-003 05564-004 –15 TIME (10µs/DIV) INPUT VOLTAGE (V) Figure 15. Large Signal Transient Response, VSY = ±15 V 4 3 2 0.3 Figure 18. Positive Overvoltage Recovery 50 VIN = 200mV p-p AVO = –100 40 RL = 10kΩ 30 VIN 0 –0.1 –0.2 VOUT –0.3 –10 –20 –30 36 20 10 0 VIN = ±3.5V RL = 2kΩ AV = +1 0.2 0.1 INPUT VOLTAGE (V) VOLTAGE (V) 1 0 –1 –2 –0.4 –3 –4 TIME (10µs/DIV) –0.5 –4 05564-028 1 6 11 16 TIME (µs) 21 26 31 Figure 16. Large Signal Transient Response, VSY = ±5 V 70 60 50 AV = +1 VIN = 100mV p-p 180 160 140 120 Figure 19. Negative Overvoltage Recovery OVERSHOOT (%) 40 +OS 30 –OS 20 10 0 CMRR (dB) 05564-012 100 80 60 40 20 0 1 10 100 1k 10k 100k –20 10 100 1k 10k 100k 1M 10M 100M CAPACITANCE (pF) FREQUENCY (Hz) Figure 17. Small Signal Overshoot vs. Load Capacitance Figure 20. CMRR vs. Frequency Rev. A | Page 8 of 12 AD8675 160 140 120 1000 TA = 25°C SOURCE VS – VOUT (mV) 100 –PSRR 100 PSRR (dB) 80 60 +PSRR 40 20 0 100 1k 10k 100k 1M 10M 100M 05564-022 10 SINK 0.01 0.1 1 10 100 FREQUENCY (Hz) LOAD CURRENT (mA) Figure 21. PSRR vs. Frequency 148 147 146 145 144 143 142 141 140 –40 14.86 14.84 14.82 Figure 24. Output Saturation Voltage vs. Output Current VS = ±15V RL = 2kΩ VOH +SWING (V) PSRR (dB) 14.80 14.78 14.76 14.74 14.72 14.70 –40 05564-023 –20 0 20 40 60 80 100 120 –20 0 20 40 60 80 100 120 TEMPERATURE (°C) TEMPERATURE (°C) Figure 22. Power Supply Rejection Ratio vs. Temperature 0.06 –14.70 Figure 25. Swing vs. Temperature, VOH VS = ±15V RL = 2kΩ 0.04 –14.75 0.02 –14.80 –SWING (V) NOISE (µV) VOL –14.85 0 –0.02 –14.90 –0.04 –14.95 0 1 2 3 4 5 TIME (s) 6 7 8 9 10 05564-021 –20 0 20 40 60 80 100 120 TEMPERATURE (°C) Figure 23. Voltage Noise (0.1 Hz to 10 Hz) Figure 26. Swing vs. Temperature, VOL Rev. A | Page 9 of 12 05564-033 –0.06 –15.00 –40 05564-032 05564-010 –20 10 1 0.001 AD8675 100kΩ 1 V+ – INPUT + 2 8 AD8675 3 4 7 6 OUTPUT V– Figure 27. Optional Offset Nulling Circuit Rev. A | Page 10 of 12 05564-031 VOS TRIM RANGE IS TYPICALLY ±3.5mV AD8675 OUTLINE DIMENSIONS 5.00 (0.1968) 4.80 (0.1890) 3.20 3.00 2.80 6.20 (0.2441) 5.80 (0.2284) 4.00 (0.1574) 3.80 (0.1497) 8 1 5 4 1.27 (0.0500) BSC 0.25 (0.0098) 0.10 (0.0040) COPLANARITY 0.10 SEATING PLANE 1.75 (0.0688) 1.35 (0.0532) 0.50 (0.0196) 0.25 (0.0099) 8° 0° 0.25 (0.0098) 0.17 (0.0067) 1.27 (0.0500) 0.40 (0.0157) 3.20 3.00 2.80 45° 8 5 1 5.15 4.90 4.65 4 PIN 1 0.65 BSC 0.95 0.85 0.75 0.15 0.00 012407-A 0.51 (0.0201) 0.31 (0.0122) 1.10 MAX 8° 0° 0.80 0.60 0.40 COMPLIANT TO JEDEC STANDARDS MS-012-A A 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. 0.38 0.22 SEATING PLANE 0.23 0.08 COPLANARITY 0.10 COMPLIANT TO JEDEC STANDARDS MO-187-AA Figure 28. 8-Lead Standard Small Outline Package [SOIC_N] Narrow Body (R-8) Dimensions shown in millimeters and (inches) Figure 29. 8-Lead Mini Small Outline Package [MSOP] (RM-8) Dimensions shown in millimeters ORDERING GUIDE Model AD8675ARMZ-R2 1 AD8675ARMZ-REEL1 AD8675ARZ1 AD8675ARZ-REEL1 AD8675ARZ-REEL71 1 Temperature Range −40°C to +125°C −40°C to +125°C −40°C to +125°C −40°C to +125°C −40°C to +125°C Package Description 8-Lead Mini Small Outline Package [MSOP] 8-Lead Mini Small Outline Package [MSOP] 8-Lead Standard Small Outline Package [SOIC_N] 8-Lead Standard Small Outline Package [SOIC_N] 8-Lead Standard Small Outline Package [SOIC_N] Package Option RM-8 RM-8 R-8 R-8 R-8 Branding A08 A08 Z = RoHS Compliant Part. Rev. A | Page 11 of 12 AD8675 NOTES ©2005-2007 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. D05564-0-4/07(A) Rev. A | Page 12 of 12