AD8500

Micropower Precision CMOS Operational Amplifier AD8500 FEATURES Supply current: 1 μA maximum Offset voltage: 1 mV maximum Single-supply or dual-supply operation Rail-to-rail input and output No phase reversal Unity gain stable PIN CONFIGURATION OUT A 1 V– 2 +IN 3 5 V+ 06005-001 AD8500 TOP VIEW (Not to Scale) 4 –IN Figure 1. 5-Lead SC70 APPLICATIONS Portable equipment Remote sensors Low power filters Threshold detectors Current sensing GENERAL DESCRIPTION The AD8500 is a low power, precision CMOS op amp featuring a maximum supply current of 1 μA. The AD8500 has a maximum offset voltage of 1 mV and a typical input bias current of 1 pA; it operates rail-to-rail on both the input and output. The AD8500 can operate from a single-supply voltage of +1.8 V to +5.5 V or a dual-supply voltage of ±0.9 V to ±2.75 V. With its low power consumption, low input bias current, and rail-to-rail input and output, the AD8500 is ideally suited for a variety of battery-powered portable applications. Potential applications include ECGs, pulse monitors, glucose meters, smoke and fire detectors, vibration monitors, and backup battery sensors. The ability to swing rail-to-rail at both the input and output helps maximize dynamic range and signal-to-noise ratio in systems that operate at very low voltages. The low offset voltage allows the AD8500 to be used in systems with high gain without having excessively large output offset errors, and it provides high accuracy without the need for system calibration. The AD8500 is fully specified over the industrial temperature range (−40°C to +85°C) and is operational over the extended industrial temperature range (−40°C to +125°C). It is available in a 5-lead, SC70 surface-mount package. 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 ©2006 Analog Devices, Inc. All rights reserved. AD8500 TABLE OF CONTENTS Features .............................................................................................. 1 Applications....................................................................................... 1 General Description ......................................................................... 1 Pin Configuration............................................................................. 1 Revision History ............................................................................... 2 Specifications..................................................................................... 3 Electrical Characteristics............................................................. 3 Absolute Maximum Ratings ............................................................5 Thermal Resistance .......................................................................5 ESD Caution...................................................................................5 Typical Performance Characteristics ..............................................6 Outline Dimensions ....................................................................... 12 Ordering Guide .......................................................................... 12 REVISION HISTORY 8/06—Rev. 0 to Rev. A Updated Format..................................................................Universal Changes to Figure 17, Figure 18, and Figure 19 ........................... 8 4/06—Revision 0: Initial Version Rev. A | Page 2 of 12 AD8500 SPECIFICATIONS ELECTRICAL CHARACTERISTICS @ VS = 5 V, VCM = VS/2, TA = 25°C, unless otherwise noted. Table 1. Parameter INPUT CHARACTERISTICS Offset Voltage Offset Voltage Drift Input Voltage Range Input Bias Current Symbol VOS ∆VOS/∆T IB −40°C < TA < +85°C −40°C < TA < +125°C Input Offset Current IOS −40°C < TA < +85°C −40°C < TA < +125°C 0 V < VCM < 5 V −40°C < TA < +85°C 0.1 V < VOUT < 4.9 V 0.1 V < VOUT < 4.9 V; −40°C < TA < +85°C 0.5 Conditions 0 V < VCM < 5 V −40°C < TA < +85°C −0.3 1 Min Typ 0.235 3 Max 1 10 +5.3 10 100 600 5 50 100 Unit mV μV/°C V pA pA pA pA pA pA dB dB dB dB pF pF V V mV mV mA dB dB μA μA μA V/μs kHz Degrees μV p-p nV/√Hz pA/√Hz Common-Mode Rejection Ratio Large Signal Voltage Gain Input Capacitance OUTPUT CHARACTERISTICS Output Voltage High Output Voltage Low Short-Circuit Current POWER SUPPLY Power Supply Rejection Ratio Supply Current/Amplifier CMRR AVO CDIFF CCM VOH VOL ISC PSRR ISY 75 70 98 80 90 90 120 2 4.5 RLOAD = 100 kΩ to GND RLOAD = 10 kΩ to GND RLOAD = 100 kΩ to VS RLOAD = 10 kΩ to VS VOUT = GND 1.8 V < VS < 5 V −40°C < TA < +85°C VO = VS/2 −40°C < TA < +85°C −40°C < TA < +125°C 4.970 4.900 4.995 4.960 0.85 6.5 ±5 110 0.75 5 15 90 80 1 1.5 2 DYNAMIC PERFORMANCE Slew Rate Gain Bandwidth Product Phase Margin NOISE PERFORMANCE Peak-to-Peak Noise Voltage Noise Density Current Noise Density SR GBP ØO 0.1 Hz to 10 Hz f = 1 kHz f = 1 kHz 0.004 7 60 6 190 0.1 en in Rev. A | Page 3 of 12 AD8500 @ VS = 1.8 V, VCM = VS/2, TA = 25°C, unless otherwise noted. Table 2. Parameter INPUT CHARACTERISTICS Offset Voltage Offset Voltage Drift Input Voltage Range Input Bias Current Symbol VOS ∆VOS/∆T IB −40°C < TA < +85°C −40°C < TA < +125°C Input Offset Current IOS −40°C < TA < +85°C −40°C < TA < +125°C 0 V < VCM < 1.8 V −40°C < TA < +85°C 0.1 V < VOUT < 1.7 V 0.1 V < VOUT < 1.7 V; −40°C < TA < +85°C 0.5 Conditions 0 V < VCM < 1.8 V −40°C < TA < +85°C −0.3 1 Min Typ 0.235 3.5 Max 1 12 +2.1 10 100 600 5 50 100 Unit mV μV/°C V pA pA pA pA pA pA dB dB dB dB pF pF V V 5 15 mV mV mA dB dB μA μA μA V/μs kHz Degrees μV p-p nV/√Hz pA/√Hz Common-Mode Rejection Ratio Large Signal Voltage Gain Input Capacitance OUTPUT CHARACTERISTICS Output Voltage High Output Voltage Low Short-Circuit Current POWER SUPPLY Power Supply Rejection Ratio Supply Current/Amplifier CMRR AVO CDIFF CCM VOH VOL ISC PSRR ISY 65 60 88 70 85 83 115 2 4.5 RLOAD = 100 kΩ to GND RLOAD = 10 kΩ to GND RLOAD = 100 kΩ to VS RLOAD = 10 kΩ to VS 1.790 1.760 1.798 1.783 0.70 5 ±2 1.8 V < VS < 5 V −40°C < TA < +85°C VO = VS/2 −40°C < TA < +85°C −40°C < TA < +125°C 90 80 110 0.65 1 1.5 2 DYNAMIC PERFORMANCE Slew Rate Gain Bandwidth Product Phase Margin NOISE PERFORMANCE Peak-to-Peak Noise Voltage Noise Density Current Noise Density SR GBP ØO 0.1 Hz to 10 Hz f = 1 kHz f = 1 kHz 0.004 7 60 6 190 0.1 en in Rev. A | Page 4 of 12 AD8500 ABSOLUTE MAXIMUM RATINGS TA = 25°C, unless otherwise noted. Table 3. Parameter Supply Voltage Input Voltage Differential Input Voltage Output Short-Circuit Duration to GND Storage Temperature Range Operating Temperature Range Junction Temperature Range Lead Temperature (Soldering, 60 sec) Rating 6V VSS − 0.4 V to VDD + 0.4 V ±6 V Indefinite −65°C to +150°C −40°C to +125°C −65°C to +150°C 300°C 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. Absolute maximum ratings apply at 25°C, unless otherwise noted. THERMAL RESISTANCE θJA is specified for the worst-case conditions, that is, a device soldered in a circuit board for surface-mount packages. Table 4. Thermal Characteristics Package Type 5-Lead SC70 (KS-5) θJA 376 θJC 126 Unit °C/W ESD CAUTION ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily accumulate on the human body and test equipment and can discharge without detection. Although this product features proprietary ESD protection circuitry, permanent damage may occur on devices subjected to high energy electrostatic discharges. Therefore, proper ESD precautions are recommended to avoid performance degradation or loss of functionality. Rev. A | Page 5 of 12 AD8500 TYPICAL PERFORMANCE CHARACTERISTICS 1200 1000 1000 100 INPUT BIAS CURRENT (pA) NUMBER OF AMPLIFIERS 800 10 600 1 400 0.1 200 0.01 06005-002 –750 –500 –250 0 VOS (µV) 250 500 750 1000 –20 0 20 40 60 80 100 120 TEMPERATURE (°C) Figure 2. Input Offset Voltage Distribution (0 V < VCM < 5.0 V) 12 Figure 5. Input Bias Current vs. Temperature (VS = 1.8 V and 5.0 V) 1000 IB (+125°C) 10 100 INPUT BIAS CURRENT (pA) NUMBER OF AMPLIFIERS IB (+85°C) 10 8 6 1 IB (+25°C) 0.1 4 2 0.01 IB (–40°C) 06005-003 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 TCVOS (µV/°C) 4.5 5.0 5.5 6.0 0 0.5 1.0 1.5 2.0 2.5 VCM (V) 3.0 3.5 4.0 4.5 5.0 Figure 3. Input Offset Voltage Drift Distribution (−40°C < TA < +85°C) 1000 800 600 NUMBER OF AMPLIFIERS Figure 6. Input Bias Current vs. Common-Mode Voltage 70 60 50 40 30 20 10 0 0.5 400 VOS (µV) 200 0 –200 –400 –600 –800 06005-004 0 1 2 3 VCM (V) 4 5 0.6 0.7 0.8 0.9 1.0 SUPPLY CURRENT (µA) Figure 4. Input Offset Voltage vs. Common-Mode Voltage Figure 7. Supply Current Distribution Rev. A | Page 6 of 12 06005-007 –1000 06005-006 0 0.001 06005-005 0 –1000 0.001 –40 AD8500 1.0 1000 OUTPUT SATURATION VOLTAGE (mV) 0.9 0.8 0.7 100 SOURCE 10 ISY (µA) 0.6 0.5 0.4 0.3 0.2 0.1 06005-008 1 SINK 0.1 0 1 2 3 VS (V) 4 5 6 0.01 0.1 1 LOAD CURRENT (mA) Figure 8. Supply Current vs. Supply Voltage 1.2 Figure 11. Output Saturation Voltage vs. Load Current 100 OUTPUT SATURATION VOLTAGE (mV) 1.0 VOH @ 10kΩ LOAD 0.8 ISY AT 5.0V 10 VOL @ 10kΩ LOAD VOH @ 100kΩ LOAD ISY (µA) 0.6 ISY AT 1.8V 0.4 1 VOL @ 100kΩ LOAD 0.2 06005-009 –25 –10 5 20 35 50 65 80 95 110 125 –15 10 35 60 85 TEMPERATURE (°C) TEMPERATURE (°C) Figure 9. Supply Current vs. Temperature 900 80 60 40 20 Figure 12. Output Saturation Voltage vs. Temperature 135 90 45 0 0 –45 –20 –40 –60 –80 10 –90 PHASE MARGIN (Degrees) 06005-013 850 OPEN-LOOP GAIN (dB) 800 ISY (µA) 750 700 650 –135 –180 100k 06005-010 600 0 0.5 1.0 1.5 2.0 2.5 VCM (V) 3.0 3.5 4.0 4.5 5.0 100 1k FREQUENCY (Hz) 10k Figure 10. Supply Current vs. Input Common-Mode Voltage Figure 13. Open-Loop Gain and Phase vs. Frequency Rev. A | Page 7 of 12 06005-012 0 –40 0.1 –40 06005-011 0 0.01 0.001 AD8500 120 0.20 0.15 0.10 0.05 110 100 90 80 CMRR (dB) 60 50 40 30 20 VOUT (V) 70 0 –0.05 –0.10 –0.15 10 06005-014 0.1 1 FREQUENCY (kHz) 10 100 0 0.0005 TIME (Seconds) 0.0010 0.0015 Figure 14. CMRR vs. Frequency 100 90 80 70 PSRR (dB) VOUT (V) 0.10 0.05 0 –0.05 –0.10 –0.15 06005-015 Figure 17. Small Signal Transient Response (No Load) 0.20 0.15 60 50 40 30 20 10 0 0.01 0.1 1 FREQUENCY (kHz) 10 100 0 0.0005 TIME (Seconds) 0.0010 0.0015 Figure 15. PSRR vs. Frequency 35 30 25 OVERSHOOT (%) 6 Figure 18. Small Signal Transient Response (100 pF Load Capacitance) 5 OS+ VOUT (V) 4 20 15 10 5 0 10 OS– 3 2 1 –0.002 –0.001 0 0.001 0.002 0.003 0.004 0.005 0.006 0.007 0.008 LOAD CAPACITANCE (pF) TIME (Seconds) Figure 16. Small Signal Overshoot vs. Load Capacitance Figure 19. Large Signal Transient Response (No Load) Rev. A | Page 8 of 12 06005-019 100 1000 06005-016 0 06005-018 –0.20 –0.0005 06005-017 0 0.01 –0.20 –0.0005 AD8500 1000 VOLTAGE NOISE DENSITY (nV/ Hz) 06005-020 VS VOLTS (V) 100 VOUT GAIN = +1 VIN = VS/2 TIME (µs) 1 10 100 FREQUENCY (Hz) 1k 10k Figure 20. Turn-On Transient Response 4 3 2 1 0 –1 –2 –3 VOUT VIN 500 Figure 23. Voltage Noise Density (VS = 1.8 V and 5.0 V) 400 NUMBER OF AMPLIFIERS OUTPUT VOLTAGE (V) 300 200 100 06005-021 –0.001 0.001 0.003 0.005 0.007 0.009 –750 –500 -250 0 VOS (µV) 250 500 750 1000 TIME (µs) Figure 21. No Phase Reversal 4 3 12 Figure 24. Input Offset Voltage Distribution (0 V < VCM < 1.8 V) PEAK-TO-PEAK VOLTAGE (µV) 10 NUMBER OF AMPLIFIERS 2 1 0 –1 –2 –3 06005-022 8 6 4 2 –4 –3 –2 –1 0 1 2 3 4 5 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0 7.5 8.0 8.5 TCVOS (µV/°C) TIME (Seconds) Figure 22. 0.1 Hz to 10 Hz Input Voltage Noise (VS = 5 V and 1.8 V) Figure 25. Input Offset Voltage Drift Distribution (−40°C < TA < +85°C) Rev. A | Page 9 of 12 06005-025 –4 –5 0 06005-024 –4 –0.005 –0.003 0 –1000 06005-023 10 AD8500 1000 800 600 650 700 400 VOS (µV) ISY (µA) 200 0 –200 –400 600 550 –600 –800 06005-026 0 0.3 0.6 0.9 VCM (V) 1.2 1.5 1.8 0 0.3 0.6 0.9 VCM (V) 1.2 1.5 1.8 Figure 26. Input Offset Voltage vs. Input Common-Mode Voltage 1000 IB (+125°C) Figure 29. Supply Current vs. Input Common-Mode Voltage 1000 100 IB (+85°C) OUTPUT SATURATION VOLTAGE (mV) 100 SOURCE 10 10 IB (pA) 1 IB (+25°C) 1 SINK 0.1 0.01 IB (–40°C) 06005-027 0.1 0 0.3 0.6 0.9 VCM (V) 1.2 1.5 1.8 0.01 0.1 1 LOAD CURRENT (mA) Figure 27. Input Bias Current vs. Input Common-Mode Voltage 70 60 Figure 30. Output Saturation Voltage vs. Load Current 100 OUTPUT SATURATION VOLTAGE (mV) NUMBER OF AMPLIFIERS VOH @ 10kΩ LOAD 10 VOL @ 10kΩ LOAD VOH @ 100kΩ LOAD 1 50 40 30 20 10 0 0.4 VOL @ 100kΩ LOAD 06005-028 0.5 0.6 0.7 0.8 0.9 –15 10 35 60 85 SUPPLY CURRENT (µA) TEMPERATURE (°C) Figure 28. Supply Current Distribution Figure 31. Output Saturation Voltage vs. Temperature Rev. A | Page 10 of 12 06005-031 0.1 –40 06005-030 0.001 0.01 0.001 06005-029 –1000 500 AD8500 80 60 40 20 0 0 –45 –20 –40 –60 –80 10 –90 –135 –180 100k 135 90 45 PHASE MARGIN (Degrees) 0.20 0.15 0.10 0.05 0 –0.05 –0.10 –0.15 –0.20 –0.0005 OPEN-LOOP GAIN (dB) VOUT (mV) 06005-032 100 1k FREQUENCY (Hz) 10k 0 0.0005 TIME (Seconds) 0.0010 0.0015 Figure 32. Open-Loop Gain and Phase vs. Frequency 100 90 80 0.10 0.20 0.15 Figure 35. Small Signal Transient Response (No Load) 70 CMRR (dB) VOUT (mV) 60 50 40 30 0.05 0 –0.05 –0.10 20 10 06005-033 –0.15 –0.20 –0.0005 0.1 1 FREQUENCY (kHz) 10 100 0 0.0005 0.0010 0.0015 TIME (Seconds) Figure 33. CMRR vs. Frequency 35 30 OS– 25 OVERSHOOT (%) Figure 36. Small Signal Transient Response (100 pF Load Capacitance) 2.0 1.8 1.6 1.4 VOUT (mV) 20 OS+ 15 10 5 0 10 1.2 1.0 0.8 0.6 0.4 0.2 06005-034 100 LOAD CAPACITANCE (pF) 1000 –0.002 –0.001 0 0.001 0.002 0.003 0.004 0.005 0.006 0.007 0.008 TIME (Seconds) Figure 34. Small Signal Overshoot vs. Load Capacitance Figure 37. Large Signal Transient Response (No Load) Rev. A | Page 11 of 12 06005-037 0 06005-036 0 0.01 06005-035 AD8500 OUTLINE DIMENSIONS 2.20 2.00 1.80 1.35 1.25 1.15 PIN 1 1.00 0.90 0.70 5 1 2 4 3 2.40 2.10 1.80 0.65 BSC 1.10 0.80 0.40 0.10 0.46 0.36 0.26 0.10 MAX 0.30 0.15 SEATING PLANE 0.22 0.08 0.10 COPLANARITY COMPLIANT TO JEDEC STANDARDS MO-203-AA Figure 38. 5-Lead Thin Shrink Small Outline Transistor Package [SC70] (KS-5) Dimensions shown in millimeters ORDERING GUIDE Model AD8500AKSZ-R2 1 AD8500AKSZ-REEL1 AD8500AKSZ-REEL71 1 Temperature Range −40°C to +125°C −40°C to +125°C −40°C to +125°C Package Description 5-Lead SC70 5-Lead SC70 5-Lead SC70 Package Option KS-5 KS-5 KS-5 Branding A0F A0F A0F Z = Pb-free part. ©2006 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. D06005-0-8/06(A) Rev. A | Page 12 of 12