Micropower Precision CMOS Operational Amplifier AD8500 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+ 4 –IN AD8500 TOP VIEW (Not to Scale) 06005-001 FEATURES 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. 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. 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 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 Absolute Maximum Ratings ............................................................5 Applications....................................................................................... 1 Thermal Resistance .......................................................................5 General Description ......................................................................... 1 ESD Caution...................................................................................5 Pin Configuration............................................................................. 1 Typical Performance Characteristics ..............................................6 Revision History ............................................................................... 2 Outline Dimensions ....................................................................... 12 Specifications..................................................................................... 3 Ordering Guide .......................................................................... 12 Electrical Characteristics............................................................. 3 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 Conditions VOS ∆VOS/∆T 0 V < VCM < 5 V −40°C < TA < +85°C Min Typ Max Unit 0.235 3 1 10 +5.3 10 100 600 5 50 100 2 4.5 mV μV/°C V pA pA pA pA pA pA dB dB dB dB pF pF 4.995 4.960 0.85 6.5 ±5 V V mV mV mA −0.3 IB 1 −40°C < TA < +85°C −40°C < TA < +125°C Input Offset Current IOS Common-Mode Rejection Ratio CMRR Large Signal Voltage Gain AVO Input Capacitance CDIFF CCM OUTPUT CHARACTERISTICS Output Voltage High Output Voltage Low Short-Circuit Current POWER SUPPLY Power Supply Rejection Ratio Supply Current/Amplifier DYNAMIC PERFORMANCE Slew Rate Gain Bandwidth Product Phase Margin NOISE PERFORMANCE Peak-to-Peak Noise Voltage Noise Density Current Noise Density VOH VOL ISC PSRR ISY 0.5 −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 RLOAD = 100 kΩ to GND RLOAD = 10 kΩ to GND RLOAD = 100 kΩ to VS RLOAD = 10 kΩ to VS VOUT = GND 4.970 4.900 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 SR GBP ØO en in 75 70 98 80 0.1 Hz to 10 Hz f = 1 kHz f = 1 kHz Rev. A | Page 3 of 12 90 90 120 5 15 110 0.75 1 1.5 2 dB dB μA μA μA 0.004 7 60 V/μs kHz Degrees 6 190 0.1 μV p-p nV/√Hz pA/√Hz 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 Conditions VOS ∆VOS/∆T 0 V < VCM < 1.8 V −40°C < TA < +85°C Min Typ Max Unit 0.235 3.5 1 12 +2.1 10 100 600 5 50 100 2 4.5 mV μV/°C V pA pA pA pA pA pA dB dB dB dB pF pF 1.798 1.783 V V −0.3 IB 1 −40°C < TA < +85°C −40°C < TA < +125°C Input Offset Current IOS Common-Mode Rejection Ratio CMRR Large Signal Voltage Gain AVO Input Capacitance CDIFF CCM OUTPUT CHARACTERISTICS Output Voltage High Output Voltage Low Short-Circuit Current POWER SUPPLY Power Supply Rejection Ratio Supply Current/Amplifier DYNAMIC PERFORMANCE Slew Rate Gain Bandwidth Product Phase Margin NOISE PERFORMANCE Peak-to-Peak Noise Voltage Noise Density Current Noise Density 0.5 −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 VOH RLOAD = 100 kΩ to GND RLOAD = 10 kΩ to GND VOL RLOAD = 100 kΩ to VS RLOAD = 10 kΩ to VS 65 60 88 70 1.790 1.760 0.70 5 ±2 ISC PSRR ISY 1.8 V < VS < 5 V −40°C < TA < +85°C VO = VS/2 −40°C < TA < +85°C −40°C < TA < +125°C SR GBP ØO en in 0.1 Hz to 10 Hz f = 1 kHz f = 1 kHz Rev. A | Page 4 of 12 85 83 115 90 80 5 15 110 0.65 1 1.5 2 mV mV mA dB dB μA μA μA 0.004 7 60 V/μs kHz Degrees 6 190 0.1 μV p-p nV/√Hz pA/√Hz 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 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 θJC 126 Unit °C/W AD8500 1200 1000 1000 100 INPUT BIAS CURRENT (pA) 800 600 400 10 1 0.1 0.01 200 –750 –500 –250 0 250 500 750 1000 VOS (µV) 0.001 –40 06005-002 0 –1000 0 20 40 60 80 100 120 TEMPERATURE (°C) Figure 5. Input Bias Current vs. Temperature (VS = 1.8 V and 5.0 V) Figure 2. Input Offset Voltage Distribution (0 V < VCM < 5.0 V) 12 1000 10 100 8 6 4 IB (+125°C) IB (+85°C) INPUT BIAS CURRENT (pA) NUMBER OF AMPLIFIERS –20 06005-005 NUMBER OF AMPLIFIERS TYPICAL PERFORMANCE CHARACTERISTICS 10 1 IB (+25°C) 0.1 0.01 2 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 0.001 06005-003 0 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 VCM (V) Figure 6. Input Bias Current vs. Common-Mode Voltage Figure 3. Input Offset Voltage Drift Distribution (−40°C < TA < +85°C) 70 1000 800 60 NUMBER OF AMPLIFIERS 600 200 0 –200 –400 50 40 30 20 –600 –1000 0 1 2 3 VCM (V) 4 5 0 0.5 0.6 0.7 0.8 0.9 SUPPLY CURRENT (µA) Figure 7. Supply Current Distribution Figure 4. Input Offset Voltage vs. Common-Mode Voltage Rev. A | Page 6 of 12 1.0 06005-007 10 –800 06005-004 VOS (µV) 400 06005-006 IB (–40°C) AD8500 1000 OUTPUT SATURATION VOLTAGE (mV) 0.9 0.8 0.6 0.5 0.4 0.3 0.2 0 1 2 3 4 5 6 VS (V) 0.1 0.01 0.001 1 100 0.6 ISY AT 1.8V 0.4 0 –40 –25 –10 5 20 35 50 65 80 95 110 125 TEMPERATURE (°C) VOL @ 10kΩ LOAD VOH @ 100kΩ LOAD 06005-009 0.2 10 1 VOL @ 100kΩ LOAD 0.1 –40 –15 10 35 60 85 TEMPERATURE (°C) Figure 12. Output Saturation Voltage vs. Temperature Figure 9. Supply Current vs. Temperature 900 OPEN-LOOP GAIN (dB) 850 800 750 700 650 80 135 60 90 40 45 20 0 0 –45 –20 –90 –40 –135 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 VCM (V) 5.0 06005-010 –60 0 06005-012 ISY AT 5.0V 0.8 VOH @ 10kΩ LOAD OUTPUT SATURATION VOLTAGE (mV) 1.0 ISY (µA) 0.1 Figure 11. Output Saturation Voltage vs. Load Current 1.2 ISY (µA) 0.01 LOAD CURRENT (mA) Figure 8. Supply Current vs. Supply Voltage 600 SINK 1 –80 10 100 1k 10k –180 100k FREQUENCY (Hz) Figure 13. Open-Loop Gain and Phase vs. Frequency Figure 10. Supply Current vs. Input Common-Mode Voltage Rev. A | Page 7 of 12 PHASE MARGIN (Degrees) 0 06005-008 0.1 SOURCE 10 06005-013 ISY (µA) 0.7 100 06005-011 1.0 AD8500 120 0.20 110 0.15 100 90 0.10 0.05 70 VOUT (V) 60 50 –0.05 40 30 –0.10 20 1 10 100 FREQUENCY (kHz) –0.20 –0.0005 06005-014 0.1 0 0.0005 0.0010 0.0015 06005-017 –0.15 10 0 0.01 0 0.0015 06005-018 CMRR (dB) 80 TIME (Seconds) Figure 14. CMRR vs. Frequency Figure 17. Small Signal Transient Response (No Load) 100 0.20 90 0.15 80 0.10 0.05 60 VOUT (V) PSRR (dB) 70 50 40 0 –0.05 30 –0.10 20 –0.15 10 1 10 100 FREQUENCY (kHz) –0.20 –0.0005 0.0010 Figure 18. Small Signal Transient Response (100 pF Load Capacitance) 35 6 30 5 25 OS+ 4 VOUT (V) 20 OS– 15 3 2 10 1 5 100 LOAD CAPACITANCE (pF) 1000 06005-016 OVERSHOOT (%) 0.0005 TIME (Seconds) Figure 15. PSRR vs. Frequency 0 10 0 0 –0.002 –0.001 0 0.001 0.002 0.003 0.004 0.005 0.006 TIME (Seconds) Figure 19. Large Signal Transient Response (No Load) Figure 16. Small Signal Overshoot vs. Load Capacitance Rev. A | Page 8 of 12 0.007 0.008 06005-019 0.1 06005-015 0 0.01 AD8500 1000 VOUT 06005-020 GAIN = +1 VIN = VS/2 TIME (µs) 100 10 1 10 1k 10k Figure 23. Voltage Noise Density (VS = 1.8 V and 5.0 V) Figure 20. Turn-On Transient Response 500 4 VOUT VIN 400 NUMBER OF AMPLIFIERS 3 OUTPUT VOLTAGE (V) 100 FREQUENCY (Hz) 06005-023 VOLTS (V) VOLTAGE NOISE DENSITY (nV/ Hz) VS 2 1 0 –1 –2 300 200 100 –0.001 0.001 0.003 0.005 0.007 0.009 TIME (µs) 0 –1000 06005-021 –4 –0.005 –0.003 –750 –500 -250 0 250 500 750 1000 VOS (µV) Figure 21. No Phase Reversal 06005-024 –3 Figure 24. Input Offset Voltage Distribution (0 V < VCM < 1.8 V) 12 4 10 NUMBER OF AMPLIFIERS 2 1 0 –1 –2 8 6 4 2 –4 –5 –4 –3 –2 –1 0 1 2 3 TIME (Seconds) 4 5 Figure 22. 0.1 Hz to 10 Hz Input Voltage Noise (VS = 5 V and 1.8 V) 0 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) Figure 25. Input Offset Voltage Drift Distribution (−40°C < TA < +85°C) Rev. A | Page 9 of 12 06005-025 –3 06005-022 PEAK-TO-PEAK VOLTAGE (µV) 3 AD8500 700 1000 800 600 650 200 ISY (µA) VOS (µV) 400 0 600 –200 –400 550 –600 0.6 0.9 1.2 1.5 1.8 VCM (V) 500 0 OUTPUT SATURATION VOLTAGE (mV) IB (+85°C) 0.1 0.01 IB (–40°C) 0.6 0.9 1.2 1.5 1.8 VCM (V) SOURCE 10 0.1 0.01 0.1 1 LOAD CURRENT (mA) Figure 30. Output Saturation Voltage vs. Load Current 100 OUTPUT SATURATION VOLTAGE (mV) 70 60 50 40 30 20 10 0.5 0.6 0.7 0.8 SUPPLY CURRENT (µA) 0.9 06005-028 NUMBER OF AMPLIFIERS SINK 1 Figure 27. Input Bias Current vs. Input Common-Mode Voltage 0 0.4 1.8 100 0.01 0.001 06005-027 0.3 1.5 VOH @ 10kΩ LOAD 10 VOL @ 10kΩ LOAD VOH @ 100kΩ LOAD 1 VOL @ 100kΩ LOAD 0.1 –40 –15 10 35 60 TEMPERATURE (°C) Figure 31. Output Saturation Voltage vs. Temperature Figure 28. Supply Current Distribution Rev. A | Page 10 of 12 85 06005-031 IB (pA) IB (+25°C) 0 1.2 1000 IB (+125°C) 10 0.001 0.9 Figure 29. Supply Current vs. Input Common-Mode Voltage 100 1 0.6 VCM (V) Figure 26. Input Offset Voltage vs. Input Common-Mode Voltage 1000 0.3 06005-030 0.3 06005-026 0 06005-029 –800 –1000 AD8500 45 20 0 0 –45 –20 –90 –40 0.10 –80 10 100 1k 10k 0 –0.10 –135 –60 0.05 –0.05 –0.15 –180 100k –0.20 –0.0005 06005-032 OPEN-LOOP GAIN (dB) 40 0.15 FREQUENCY (Hz) 0 0.0005 0.0010 0.0015 06005-035 90 0.0015 06005-036 60 0.20 VOUT (mV) 135 PHASE MARGIN (Degrees) 80 TIME (Seconds) Figure 35. Small Signal Transient Response (No Load) Figure 32. Open-Loop Gain and Phase vs. Frequency 0.20 100 90 0.15 80 0.10 60 VOUT (mV) CMRR (dB) 70 50 40 0.05 0 –0.05 30 –0.10 20 –0.15 10 0.1 1 10 100 FREQUENCY (kHz) –0.20 –0.0005 06005-033 0 0.01 0.0005 0.0010 TIME (Seconds) Figure 36. Small Signal Transient Response (100 pF Load Capacitance) Figure 33. CMRR vs. Frequency 35 2.0 1.8 30 1.6 OS– 25 VOUT (mV) 1.4 20 OS+ 15 1.2 1.0 0.8 0.6 10 0.4 5 100 LOAD CAPACITANCE (pF) 1000 Figure 34. Small Signal Overshoot vs. Load Capacitance 0 –0.002 –0.001 0 0.001 0.002 0.003 0.004 0.005 0.006 TIME (Seconds) Figure 37. Large Signal Transient Response (No Load) Rev. A | Page 11 of 12 0.007 0.008 06005-037 0 10 0.2 06005-034 OVERSHOOT (%) 0 AD8500 OUTLINE DIMENSIONS 2.20 2.00 1.80 1.35 1.25 1.15 5 4 1 2 3 PIN 1 2.40 2.10 1.80 0.65 BSC 1.00 0.90 0.70 1.10 0.80 0.10 MAX 0.30 0.15 0.40 0.10 SEATING PLANE 0.46 0.36 0.26 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 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 Package Option KS-5 KS-5 KS-5 Branding A0F A0F A0F