ADA4051-2ACPZ-RL

1.8 V, Micropower, Zero-Drift, Rail-to-Rail Input/Output Op Amp ADA4051-1/ADA4051-2 FEATURES Very low supply current: 13 μA typical Low offset voltage: 15 μV maximum Offset voltage drift: 20 nV/°C Single-supply operation: 1.8 V to 5.5 V High PSRR: 110 dB minimum High CMRR: 110 dB minimum Rail-to-rail input/output Unity-gain stable Extended industrial temperature range PIN CONFIGURATION OUT 1 5 V+ ADA4051-1 V– 2 +IN 3 4 –IN Figure 1. 5-Lead SOT-23 (RJ-5) +IN 1 5 V+ ADA4051-1 V– 2 –IN 3 4 OUT V– 4 5 +IN B Figure 3. 8-Lead MSOP (RM-8) OUT A 1 –IN A 2 +IN A 3 V– 4 PIN 1 INDICATOR 8 V+ 7 OUT B 6 –IN B 5 +IN B ADA4051-2 TOP VIEW (Not to Scale) 08056-001 08056-065 Pressure and position sensors Temperature measurements Electronic scales Medical instrumentation Battery-powered equipment Handheld test equipment Figure 2. 5-Lead SC-70 (KS-5) OUT A 1 –IN A 2 +IN A 3 8 V+ OUT B –IN B ADA4051-2 TOP VIEW (Not to Scale) 7 6 NOTES 1. IT IS RECOMMENDED THAT THE EXPOSED PAD BE CONNECTED TO V–. Figure 4. 8-Lead LFCSP (CP-8-2) GENERAL DESCRIPTION The ADA4051-1/ADA4051-2 are CMOS, micropower, zerodrift operational amplifiers utilizing an innovative chopping technique. These amplifiers feature rail-to-rail input/output swing and extremely low offset voltage while operating from a 1.8 V to 5.5 V power supply. In addition, these amplifiers offer high power supply rejection ratio (PSRR) and common-mode rejection ratio (CMRR) while operating with a typical supply current of 13 μA per amplifier. This combination of features makes the ADA4051-1/ADA4051-2 amplifiers ideal choices for battery-powered applications where high precision and low power consumption are important. The ADA4051-1/ADA4051-2 are specified for the extended industrial temperature range of −40°C to +125°C. The ADA4051-1 amplifier is available in 5-lead SOT-23 and 5-lead SC-70 packages. The ADA4051-2 amplifier is available in 8-lead MSOP and 8-lead LFCSP packages. The ADA4051-1/ADA4051-2 are members of a growing series of zero-drift op amps offered by Analog Devices, Inc. Refer to Table 1 for a list of these devices. Table 1. Op Amps Supply Single Dual Quad Low Power, 5 V AD8538 AD8539 5V AD8628 AD8629 AD8630 16 V AD8638 AD8639 Rev. B 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 ©2009–2010 Analog Devices, Inc. All rights reserved. 08056-066 APPLICATIONS TOP VIEW (Not to Scale) 08056-064 TOP VIEW (Not to Scale) ADA4051-1/ADA4051-2 TABLE OF CONTENTS Features .............................................................................................. 1  Applications ....................................................................................... 1  Pin Configuration ............................................................................. 1  General Description ......................................................................... 1  Revision History ............................................................................... 2  Specifications..................................................................................... 3  Electrical Characteristics—1.8 V Operation ............................ 3  Electrical Characteristics—5 V Operation................................ 4  Absolute Maximum Ratings............................................................ 5  Thermal Resistance .......................................................................5  Power Sequencing .........................................................................5  ESD Caution...................................................................................5  Typical Performance Characteristics ..............................................6  Theory of Operation ...................................................................... 15  Input Voltage Range ................................................................... 16  Output Phase Reversal ............................................................... 16  Outline Dimensions ....................................................................... 17  Ordering Guide .......................................................................... 18  REVISION HISTORY 1/10—Rev. A to Rev. B Added ADA4051-1, 5-Lead SC-70 Package .................... Universal Added Figure 2; Renumbered Sequentially .................................. 1 Changes to Figure 4 and General Description Section ............... 1 Changes to Electrical Characteristics—1.8 V Operation Section and Table 2 ......................................................................................... 3 Changes to Electrical Characteristics—5 V Operation Section and Table 3 ......................................................................................... 4 Changes to Table 5 ............................................................................ 5 Updated Outline Dimensions ....................................................... 17 Changes to Ordering Guide .......................................................... 18 10/09—Rev. 0 to Rev. A Added ADA4051-1, 5-Lead SOT-23 Package ................. Universal Added ADA4051-2, 8-Lead LFCSP Package .................. Universal Changes to the Features and General Description Section, Added Figure 1 and Figure 3 ........................................................... 1 Moved Electrical Characteristics—1.8 V Operation Section .... 3 Changes to Offset Voltage Parameter and Supply Current per Amplifier Parameter, Table 2 .......................................................... 3 Moved Electrical Characteristics—5 V Operation Section ........ 4 Changes to Offset Voltage Parameter and Supply Current per Amplifier Parameter, Table 2 .......................................................... 4 Changes to Thermal Resistance Section and Table 5................... 5 Changes to Figure 22 and Figure 25 ............................................... 9 Changes to Theory of Operation Section .................................... 15 Updated Outline Dimensions ....................................................... 17 Changes to Ordering Guide .......................................................... 18 7/09—Revision 0: Initial Version Rev. B | Page 2 of 20 ADA4051-1/ADA4051-2 SPECIFICATIONS ELECTRICAL CHARACTERISTICS—1.8 V OPERATION VSY = 1.8 V, VCM = VSY/2 V, TA = 25°C, RL = 100 kΩ to GND, unless otherwise noted. Table 2. Parameter INPUT CHARACTERISTICS Offset Voltage ADA4051-2 ADA4051-1 Offset Voltage Drift Input Bias Current Input Offset Current Input Voltage Range Common-Mode Rejection Ratio Large-Signal Voltage Gain Symbol VOS 0 V ≤ VCM ≤ 1.8 V 0 V ≤ VCM ≤ 1.8 V −40°C ≤ TA ≤ +125°C −40°C ≤ TA ≤ +125°C IOS −40°C ≤ TA ≤ +125°C −40°C ≤ TA ≤ +125°C 0 V ≤ VCM ≤ 1.8 V −40°C ≤ TA ≤ +125°C RL = 10 kΩ to VCM, 0.1 V ≤ VOUT ≤ VSY − 0.1 V −40°C ≤ TA ≤ +125°C 0 105 100 106 100 8 2 5 RL = 100 kΩ to VCM −40°C ≤ TA ≤ +125°C RL = 10 kΩ to VCM −40°C ≤ TA ≤ +125°C RL = 100 kΩ to VCM −40°C ≤ TA ≤ +125°C RL = 10 kΩ to VCM −40°C ≤ TA ≤ +125°C VOUT = VSY or GND f = 1 kHz, G = 10 1.8 V ≤ VSY ≤ 5.5 V −40°C ≤ TA ≤ +125°C VOUT = VSY/2 VOUT = VSY/2 −40°C ≤ TA ≤ +125°C SR+ SR− tS GBP ΦM CS en p-p en in RL = 10 kΩ, CL = 100 pF, G = 1 RL = 10 kΩ, CL = 100 pF, G = 1 To 0.1%, VIN = 1 V p-p, RL = 10 kΩ, CL = 100 pF CL = 100 pF, G = 1 CL = 100 pF, G = 1 VIN = 1.7 V, f = 100 Hz f = 0.1 Hz to 10 Hz f = 1 kHz f = 1 kHz Rev. B | Page 3 of 20 Test Conditions/Comments Min Typ Max Unit ∆VOS/∆T IB 2 2 0.02 5 10 15 17 0.1 50 200 100 150 1.8 CMRR AVO 125 130 μV μV μV/°C pA pA pA pA V dB dB dB dB MΩ pF pF V V V V mV mV mV mV mA Ω dB dB Input Resistance Input Capacitance, Differential Mode Input Capacitance, Common Mode OUTPUT CHARACTERISTICS Output Voltage High RIN CINDM CINCM VOH 1.796 1.79 1.76 1.7 1.799 1.796 1 3 13 1 3 9 20 40 Output Voltage Low VOL Short-Circuit Current Closed-Loop Output Impedance POWER SUPPLY Power Supply Rejection Ratio Supply Current per Amplifier ADA4051-2 ADA4051-1 DYNAMIC PERFORMANCE Slew Rate Settling Time Gain Bandwidth Product Phase Margin Channel Separation NOISE PERFORMANCE Voltage Noise Voltage Noise Density Current Noise Density ISC ZOUT PSRR ISY 110 106 135 13 15 17 18 20 μA μA μA V/μs V/μs μs kHz Degrees dB μV p-p nV/√Hz fA/√Hz 0.04 0.03 120 115 40 140 1.96 95 100 ADA4051-1/ADA4051-2 ELECTRICAL CHARACTERISTICS—5 V OPERATION VSY = 5.0 V, VCM = VSY/2 V, TA = 25°C, RL = 100 kΩ to GND, unless otherwise noted. Table 3. Parameter INPUT CHARACTERISTICS Offset Voltage ADA4051-2 ADA4051-1 Offset Voltage Drift Input Bias Current Input Offset Current Input Voltage Range Common-Mode Rejection Ratio Large-Signal Voltage Gain Symbol VOS 0 V ≤ VCM ≤ 5 V 0 V ≤ VCM ≤ 5 V −40°C ≤ TA ≤ +125°C −40°C ≤ TA ≤ +125°C IOS −40°C ≤ TA ≤ +125°C −40°C ≤ TA ≤ +125°C 0 V ≤ VCM ≤ 5 V −40°C ≤ TA ≤ +125°C RL = 10 kΩ to VCM, 0.1 V ≤ VOUT ≤ VSY − 0.1 V −40°C ≤ TA ≤ +125°C 0 110 106 115 106 8 2 5 RL = 100 kΩ to VCM −40°C ≤ TA ≤ +125°C RL = 10 kΩ to VCM −40°C ≤ TA ≤ +125°C RL = 100 kΩ to VCM −40°C ≤ TA ≤ +125°C RL = 10 kΩ to VCM −40°C ≤ TA ≤ +125°C VOUT = VSY or GND f = 1 kHz, G = 10 1.8 V ≤ VSY ≤ 5.5 V −40°C ≤ TA ≤ +125°C VOUT = VSY/2 VOUT = VSY/2 −40°C ≤ TA ≤ +125°C SR+ SR− tS GBP ΦM CS en p-p en in RL = 10 kΩ, CL = 100 pF, G = 1 RL = 10 kΩ, CL = 100 pF, G = 1 To 0.1%, VIN = 1 V p-p, RL = 10 kΩ, CL = 100 pF CL = 100 pF, G = 1 CL = 100 pF, G = 1 VIN = 4.99 V, f = 100 Hz f = 0.1 Hz to 10 Hz f = 1 kHz f = 1 kHz 4.996 4.985 4.96 4.9 4.998 4.99 1 9 15 1 110 106 135 4 13 30 90 40 2 2 0.02 20 15 17 0.1 70 200 100 150 5 μV μV μV/°C pA pA pA pA V dB dB dB dB MΩ pF pF V V V V mV mV mV mV mA Ω dB dB 17 18 20 μA μA μA V/μs V/μs μs kHz Degrees dB μV p-p nV/√Hz fA/√Hz Test Conditions/Comments Min Typ Max Unit ∆VOS/∆T IB CMRR AVO 135 135 Input Resistance Input Capacitance, Differential Mode Input Capacitance, Common Mode OUTPUT CHARACTERISTICS Output Voltage High RIN CINDM CINCM VOH Output Voltage Low VOL Short-Circuit Current Closed-Loop Output Impedance POWER SUPPLY Power Supply Rejection Ratio Supply Current per Amplifier ADA4051-2 ADA4051-1 DYNAMIC PERFORMANCE Slew Rate Settling Time Gain Bandwidth Product Phase Margin Channel Separation NOISE PERFORMANCE Voltage Noise Voltage Noise Density Current Noise Density ISC ZOUT PSRR ISY 13 15 0.06 0.04 110 125 40 140 1.96 95 100 Rev. B | Page 4 of 20 ADA4051-1/ADA4051-2 ABSOLUTE MAXIMUM RATINGS Table 4. Parameter Supply Voltage Input Voltage Input Current1 Differential Input Voltage2 Output Short-Circuit Duration to GND Storage Temperature Range Operating Temperature Range Junction Temperature Range Lead Temperature (Soldering, 60 sec) 1 THERMAL RESISTANCE Rating 6V ±VSY ± 0.3 V ±10 mA ±VSY Indefinite −65°C to +150°C −40°C to +125°C −65°C to +150°C 300°C θJA is specified for the worst-case conditions, that is, a device soldered on a circuit board for surface-mount packages with its exposed paddle soldered to a pad, if applicable. Table 5 shows simulated thermal values for a 4-layer (2S2P) JEDEC standard thermal test board, unless otherwise specified. Table 5. Thermal Resistance Package Type 5-Lead SOT-23 (RJ-5) 5-Lead SC-70 (KS-5) 8-Lead MSOP (RM-8) 8-Lead LFCSP (CP-8-2) θJA 190 534 142 77 θJC 92 173 45 14 Unit °C/W °C/W °C/W °C/W The input pins have clamp diodes to the power supply pins. Limit the input current to 10 mA or less whenever input signals exceed the power supply rail by 0.3 V. 2 Inputs are protected against high differential voltages by internal series 1.33 kΩ resistors and back-to-back diode-connected N-MOSFETs (with a typical VT of 0.7 V for VCM of 0 V). POWER SEQUENCING The op amp supplies must be established simultaneously with or before any input signals are applied. If this is not possible, the input current must be limited to 10 mA. 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. ESD CAUTION Rev. B | Page 5 of 20 ADA4051-1/ADA4051-2 TYPICAL PERFORMANCE CHARACTERISTICS TA = 25°C, unless otherwise noted. 300 VSY = 1.8V VCM = VSY/2 250 NUMBER OF AMPLIFIERS NUMBER OF AMPLIFIERS 300 VSY = 5V VCM = VSY/2 250 200 200 150 150 100 100 50 50 VOS (µV) VOS (µV) Figure 5. Input Offset Voltage Distribution Figure 8. Input Offset Voltage Distribution 10 VSY = 1.8V –40°C ≤ TA ≤ +125°C 8 VSY = 5V –40°C ≤ TA ≤ 125°C 8 NUMBER OF AMPLIFIERS 6 NUMBER OF AMPLIFIERS 6 4 4 2 2 0 08056-003 TCVOS (µV/°C) TCVOS (µV/°C) Figure 6. Input Offset Voltage Drift Distribution with Temperature Figure 9. Input Offset Voltage Drift Distribution with Temperature 15 VSY = 1.8V 10 15 VSY = 5V 10 5 5 VOS (µV) VOS (µV) 0 DEVICE 1 DEVICE 2 DEVICE 3 DEVICE 4 DEVICE 5 DEVICE 6 DEVICE 7 DEVICE 8 DEVICE 9 DEVICE 10 08056-004 0 DEVICE 1 DEVICE 2 DEVICE 3 DEVICE 4 DEVICE 5 DEVICE 6 DEVICE 7 DEVICE 8 DEVICE 9 DEVICE 10 08056-007 –5 –5 –10 –10 –15 0 0.3 0.6 0.9 VCM (V) 1.2 1.5 1.8 –15 0 1 2 VCM (V) 3 4 5 Figure 7. Input Offset Voltage vs. Input Common-Mode Voltage Figure 10. Input Offset Voltage vs. Input Common-Mode Voltage Rev. B | Page 6 of 20 08056-006 0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.10 0 0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.10 08056-005 –10 –8 –6 –4 –2 0 2 4 6 8 10 08056-002 0 0 –10 –8 –6 –4 –2 0 2 4 6 8 10 ADA4051-1/ADA4051-2 TA = 25°C, unless otherwise noted. 100 VSY = 1.8V IB+ IB– 100 VSY = 5V IB+ IB– 80 80 60 60 IB (pA) 08056-008 IB (pA) 40 40 20 20 0 0 25 50 75 TEMPERATURE (°C) 100 125 25 50 75 TEMPERATURE (°C) 100 125 Figure 11. Input Bias Current vs. Temperature Figure 14. Input Bias Current vs. Temperature 200 150 100 50 VSY = 1.8V 400 300 200 100 IB (pA) VSY = 5V IB (pA) 0 –50 –100 –150 –200 IB+, 25°C IB–, 25°C IB+, 85°C IB–, 85°C IB+, 125°C IB–, 125°C 08056-009 0 –100 –200 –300 –400 IB+, 25°C IB–, 25°C IB+, 85°C IB–, 85°C IB+, 125°C IB–, 125°C 08056-012 08056-013 0 0.3 0.6 0.9 VCM (V) 1.2 1.5 1.8 0 0.5 1.0 1.5 2.0 2.5 VCM (V) 3.0 3.5 4.0 4.5 5.0 Figure 12. Input Bias Current vs. Common-Mode Voltage and Temperature Figure 15. Input Bias Current vs. Common-Mode Voltage and Temperature OUTPUT VOLTAGE (VOH) TO SUPPLY RAIL (mV) OUTPUT VOLTAGE (VOH) TO SUPPLY RAIL (mV) 10,000 VSY = 1.8V 10,000 VSY = 5V 1000 1000 100 100 10 10 1 1 0.1 0.01 0.1 LOAD CURRENT (mA) 1 10 08056-010 0.01 0.001 –40°C +25°C +85°C +125°C 0.1 0.01 0.001 –40°C +25°C +85°C +125°C 0.01 0.1 1 10 100 LOAD CURRENT (mA) Figure 13. Output Voltage (VOH) to Supply Rail vs. Load Current and Temperature Figure 16. Output Voltage (VOH) to Supply Rail vs. Load Current and Temperature Rev. B | Page 7 of 20 08056-011 –20 –20 ADA4051-1/ADA4051-2 TA = 25°C, unless otherwise noted. OUTPUT VOLTAGE (VOL) TO SUPPLY RAIL (mV) OUTPUT VOLTAGE (VOL) TO SUPPLY RAIL (mV) 10,000 VSY = 1.8V 10,000 VSY = 5V 1000 1000 100 100 10 10 1 1 0.1 0.01 0.1 1 10 100 08056-014 0.01 0.1 1 10 100 LOAD CURRENT (mA) LOAD CURRENT (mA) Figure 17. Output Voltage (VOL) to Supply Rail vs. Load Current and Temperature Figure 20. Output Voltage (VOL) to Supply Rail vs. Load Current and Temperature 1800 RL = 100kΩ OUTPUT VOLTAGE [VOH] (mV) 5000 4998 4996 4994 4992 4990 4988 4986 4984 08056-015 RL = 100kΩ 1799 OUTPUT VOLTAGE [VOH] (mV) 1798 1797 RL = 10kΩ RL = 10kΩ 1796 1795 VSY = 1.8V VCM = VSY/2 –25 –10 5 20 35 50 65 80 95 110 125 VSY = 5V VCM = VSY/2 4982 –40 –25 –10 5 20 35 50 65 80 95 110 125 TEMPERATURE (°C) TEMPERATURE (°C) Figure 18. Output Voltage (VOH) vs. Temperature Figure 21. Output Voltage (VOH) vs. Temperature 14 12 OUTPUT VOLTAGE [VOL] (mV) VSY = 1.8V VCM = VSY/2 OUTPUT VOLTAGE [VOL] (mV) 14 12 10 8 6 4 2 RL = 100kΩ 08056-016 VSY = 5V VCM = VSY/2 10 8 6 4 2 0 –40 RL = 10kΩ RL = 10kΩ RL = 100kΩ –25 –10 5 20 35 50 65 80 95 110 125 08056-019 –25 –10 5 20 35 50 65 80 95 110 125 0 –40 TEMPERATURE (°C) TEMPERATURE (°C) Figure 19. Output Voltage (VOL) vs. Temperature Figure 22. Output Voltage (VOL) vs. Temperature Rev. B | Page 8 of 20 08056-018 1794 –40 08056-017 0.01 0.001 –40°C +25°C +85°C +125°C 0.1 0.01 0.001 –40°C +25°C +85°C +125°C ADA4051-1/ADA4051-2 TA = 25°C, unless otherwise noted. 30 ADA4051-2 ADA4051-1 30 VCM = VSY/2 25 TOTAL SUPPLY CURRENT ( µA) TOTAL SUPPLY CURRENT (µA) 25 20 20 15 15 10 10 ADA4051-2, ADA4051-2, ADA4051-1, ADA4051-1, –25 –10 5 20 35 50 65 80 95 1.8V 5V 1.8V 5V 110 125 08056-023 5 VCM = VSY/2 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 08056-020 5 0 0 –40 SUPPLY VOLTAGE (V) TEMPERATURE (°C) Figure 23. Total Supply Current vs. Supply Voltage Figure 26. Total Supply Current vs. Temperature 80 60 VSY = 1.8V CL= 100pF 180 135 80 60 OPEN-LOOP GAIN (dB) 180 VSY = 5V CL= 100pF 135 90 PHASE GAIN 45 0 –45 –90 –135 08056-025 08056-062 OPEN-LOOP GAIN (dB) 40 20 GAIN 0 –20 –40 –60 100 PHASE 90 40 20 0 –20 –40 –60 100 45 0 –45 –90 –135 PHASE (Degrees) 08056-022 1k 10k FREQUENCY (Hz) 100k 1M 1k 10k FREQUENCY (Hz) 100k 1M Figure 24. Open-Loop Gain and Phase vs. Frequency Figure 27. Open-Loop Gain and Phase vs. Frequency 50 40 30 CLOSED-LOOP GAIN (dB) 50 VSY = 1.8V RL = 10kΩ CL = 50pF 40 30 VSY = 5V RL = 10kΩ CL = 50pF CLOSED-LOOP GAIN (dB) 20 10 0 –10 –20 –30 –40 –50 100 G=1 G = 10 G = 100 08056-061 20 10 0 –10 –20 –30 –40 G=1 G = 10 G = 100 1k 10k FREQUENCY (Hz) 100k 1M 1k 10k FREQUENCY (Hz) 100k 1M –50 100 Figure 25. Closed-Loop Gain vs. Frequency Figure 28. Closed-Loop Gain vs. Frequency Rev. B | Page 9 of 20 PHASE (Degrees) ADA4051-1/ADA4051-2 TA = 25°C, unless otherwise noted. 10k VSY = 1.8V 10k VSY = 5V 1k 1k ZOUT (Ω) 10 ZOUT (Ω) G = −1 G = −10 G = −100 10k 100k 1M 08056-026 100 100 10 1 1 G = −1 G = −10 G = −100 10k 100k 1M 08056-029 08056-031 08056-030 0.1 1k 0.1 1k FREQUENCY (Hz) FREQUENCY (Hz) Figure 29. Output Impedance vs. Frequency Figure 32. Output Impedance vs. Frequency 110 VSY = 1.8V 110 VSY = 5V 100 90 100 90 CMRR (dB) 80 70 60 50 40 10 CMRR (dB) 80 70 60 50 40 10 100 1k 10k 100k 1M 08056-027 100 1k 10k 100k 1M FREQUENCY (Hz) FREQUENCY (Hz) Figure 30. CMRR vs. Frequency Figure 33. CMRR vs. Frequency 120 VSY = 1.8V 100 120 VSY = 5V 100 80 80 PSRR (dB) 60 PSRR+ 40 PSRR (dB) 60 PSRR+ 40 20 PSRR– 1k 10k FREQUENCY (Hz) 100k 1M 08056-028 20 PSRR– 0 100 1k 10k FREQUENCY (Hz) 100k 1M 0 100 Figure 31. PSRR vs. Frequency Figure 34. PSRR vs. Frequency Rev. B | Page 10 of 20 ADA4051-1/ADA4051-2 TA = 25°C, unless otherwise noted. 60 VSY = ±0.9V VIN = 50mV p-p RL = 10kΩ CL= 50pF 60 VSY = ±2.5V VIN = 50mV p-p RL = 10kΩ CL= 50pF 50 50 OVERSHOOT (%) OVERSHOOT (%) 40 40 −OVERSHOOT 30 30 20 −OVERSHOOT +OVERSHOOT 20 +OVERSHOOT 10 10 08056-032 100 LOAD CAPACITANCE (pF) 100 LOAD CAPACITANCE (pF) Figure 35. Small-Signal Overshoot vs. Load Capacitance Figure 38. Small-Signal Overshoot vs. Load Capacitance VSY = 1.8V RL = 10kΩ CL = 100pF G=1 VIN = 1.5V p-p VOLTAGE (500mV/DIV) VSY = 5V RL = 10kΩ CL = 100pF G=1 VIN = 4V p-p VOLTAGE (1V/DIV) 08056-033 TIME (100µs/DIV) TIME (100µs/DIV) Figure 36. Large-Signal Transient Response Figure 39. Large-Signal Transient Response VSY = 1.8V RL = 10kΩ CL = 100pF G=1 VIN = 50mV p-p VSY = 5V RL = 10kΩ CL = 100pF G=1 VIN = 50mV p-p VOLTAGE (10mV/DIV) VOLTAGE (10mV/DIV) 08056-034 TIME (100µs/DIV) TIME (100µs/DIV) Figure 37. Small-Signal Transient Response Figure 40. Small-Signal Transient Response Rev. B | Page 11 of 20 08056-037 08056-036 08056-035 0 10 0 10 ADA4051-1/ADA4051-2 TA = 25°C, unless otherwise noted. VSY = 1.8V INPUT VOLTAGE NOISE (0.5µV/DIV) INPUT VOLTAGE NOISE (0.5µV/DIV) VSY = 5V 1.94µV p-p 1.96µV p-p 08056-038 TIME (4s/DIV) TIME (4s/DIV) Figure 41. Input Voltage Noise, 0.1 Hz to 10 Hz 1k 1k Figure 44. Input Voltage Noise, 0.1 Hz to 10 Hz VSY = 1.8V VOLTAGE NOISE DENSITY (nV/√Hz) VSY = 5V VOLTAGE NOISE DENSITY (nV/√Hz) 100 100 10 10 100 FREQUENCY (Hz) 1k 10k 100 FREQUENCY (Hz) 1k 10k Figure 42. Voltage Noise Density vs. Frequency 0.15 0.10 VSY = ±0.9V G = –10 Figure 45. Voltage Noise Density vs. Frequency 0.4 0.3 INPUT VOLTAGE (100mV/DIV) VSY = ±2.5V G = –10 OUTPUT VOLTAGE (1V/DIV) 08056-043 0.05 INPUT VOLTAGE 0 –0.05 OUTPUT VOLTAGE 0.5 0 –0.5 –1.0 –1.5 OUTPUT VOLTAGE (500mV/DIV) INPUT VOLTAGE (50mV/DIV) 0.2 0.1 0 –0.1 INPUT VOLTAGE OUTPUT VOLTAGE 1 0 –1 –2 08056-040 TIME (40µs/DIV) TIME (40µs/DIV) –3 Figure 43. Positive Overload Recovery Figure 46. Positive Overload Recovery Rev. B | Page 12 of 20 08056-042 08056-039 1 10 1 10 08056-041 ADA4051-1/ADA4051-2 TA = 25°C, unless otherwise noted. 0.05 0 INPUT VOLTAGE 0.1 0 OUTPUT VOLTAGE (500mV/DIV) INPUT VOLTAGE (100mV/DIV) INPUT VOLTAGE OUTPUT VOLTAGE (1V/DIV) INPUT VOLTAGE (50mV/DIV) –0.05 –0.10 –0.15 1.5 1.0 0.5 OUTPUT VOLTAGE VSY = ±0.9V G = –10 TIME (40µs/DIV) 0 –0.1 –0.2 –0.3 –0.4 4 3 2 1 OUTPUT VOLTAGE 0 –1 –0.5 08056-044 TIME (40µs/DIV) Figure 47. Negative Overload Recovery Figure 50. Negative Overload Recovery INPUT VOLTAGE INPUT VOLTAGE OUTPUT VOLTAGE (5mV/DIV) 5 ERROR BAND OUTPUT VOLTAGE 0 –5 VSY = ±0.9V VIN = 1V p-p RL = 10kΩ CL = 100pF TIME (40µs/DIV) 5 ERROR BAND OUTPUT VOLTAGE 0 –5 08056-045 TIME (40µs/DIV) Figure 48. Positive Settling Time to 0.1% Figure 51. Positive Settling Time to 0.1% OUTPUT VOLTAGE (5mV/DIV) INPUT VOLTAGE (500mV/DIV) INPUT VOLTAGE INPUT VOLTAGE 5 ERROR BAND OUTPUT VOLTAGE 0 –5 VSY = ±0.9V VIN = 1V p-p RL = 10kΩ CL = 100pF TIME (40µs/DIV) 5 ERROR BAND OUTPUT VOLTAGE 0 –5 VSY = ±2.5V VIN = 1V p-p RL = 10kΩ CL = 100pF TIME (40µs/DIV) 08056-046 OUTPUT VOLTAGE (5mV/DIV) 08056-049 Figure 49. Negative Settling Time to 0.1% INPUT VOLTAGE (500mV/DIV) Figure 52. Negative Settling Time to 0.1% Rev. B | Page 13 of 20 08056-048 VSY = ±2.5V VIN = 1V p-p RL = 10kΩ CL = 100pF OUTPUT VOLTAGE (5mV/DIV) INPUT VOLTAGE (500mV/DIV) INPUT VOLTAGE (500mV/DIV) 08056-047 VSY = ±2.5V G = –10 ADA4051-1/ADA4051-2 TA = 25°C, unless otherwise noted. –100 –100 100kΩ 1kΩ VIN = 0.5V VIN = 1V VIN = 1.7V 100kΩ 1kΩ CHANNEL SEPARATION (dB) VIN = 1V VIN = 3V VIN = 4.99V CHANNEL SEPARATION (dB) –110 –110 –120 –120 –130 –130 –140 200 2k FREQUENCY (Hz) 20k 08056-050 200 2k FREQUENCY (Hz) 20k Figure 53. Channel Separation vs. Frequency Figure 56. Channel Separation vs. Frequency 1.8 6 1.5 5 OUTPUT SWING (V) OUTPUT SWING (V) 1.2 4 0.9 3 0.6 VSY = 1.8V VIN = 1.7V G=1 RL= 10kΩ CL = 50pF 1k 10k FREQUENCY (Hz) 100k 08056-051 2 VSY = 5V VIN = 4.9V G=1 RL= 10kΩ CL = 50pF 1k 10k FREQUENCY (Hz) 100k 08056-054 0.3 1 0 100 0 100 Figure 54. Output Swing vs. Frequency Figure 57. Output Swing vs. Frequency VSY = ±0.9V G=1 RL= NO LOAD CL = NO LOAD VSY = ±2.5V G=1 RL= NO LOAD CL = NO LOAD VOLTAGE (500mV/DIV) VOUT VIN 08056-052 VOLTAGE (1V/DIV) VOUT VIN TIME (200µs/DIV) TIME (200µs/DIV) Figure 55. No Phase Reversal Figure 58. No Phase Reversal Rev. B | Page 14 of 20 08056-055 08056-053 –150 20 VSY = 1.8V G = –100 RL= 10kΩ CL= 50pF –140 –150 20 VSY = 5V G = –100 RL= 10kΩ CL = 50pF ADA4051-1/ADA4051-2 THEORY OF OPERATION The ADA4051-1/ADA4051-2 micropower chopper operational amplifiers feature a novel, patent-pending technique that suppresses offset-related ripple in a chopper amplifier. Instead of filtering the ripple in the ac domain, this technique nulls the amplifier’s initial offset in the dc domain, thus preventing ripple at the overall output. Auto-zeroing and chopping are two techniques widely used in high precision CMOS amplifiers to achieve low offset, low offset drift, and no 1/f noise. Each of these techniques has pros and cons. Auto-zeroing results in more in-band noise due to aliasing introduced by sampling. On the other hand, chopping produces offset-related ripple because it modulates the initial offset associated with the amplifier up to its chopping frequency. To accomplish the best noise vs. power trade-off, the chopping technique is the better approach when designing a low offset amplifier because there is no increased in-band noise. It is preferable to suppress the offset-related ripple inside a chopper amplifier because the offset-related ripple would otherwise need to be eliminated by an extra off-chip postfilter. Figure 59 shows the block diagram design of the ADA4051-1/ ADA4051-2 chopper amplifiers employing a local feedback loop called autocorrection feedback (ACFB). The main signal path contains an input chopping switch network (CHOP1), a first transconductance amplifier (Gm1), an output chopping switch network (CHOP2), a second transconductance amplifier (Gm2), and a third transconductance amplifier (Gm3). CHOP1 and CHOP2 operate at 40 kHz of chopping frequency to modulate the initial offset and 1/f noise from Gm1 up to the chopping frequency. A fourth transconductance amplifier (Gm4) in the ACFB senses the modulated ripple at the output of CHOP2, caused by the initial offset voltage of Gm1. Then, the ripple is demodulated down to a dc domain through a third chopping switch network (CHOP3), operating with the same chopping clock as CHOP1 and CHOP2. Finally, a null transconductance amplifier (Gm5) tries to null any dc component at the output of Gm1 that would otherwise appear in the overall output as ripple. A switched-capacitor notch filter (NF) functions to selectively suppress the undesired offset-related ripple without disturbing the desired input signal from the overall input. The desired input dc signal appears as a dc signal at the output of CHOP2. Then, the initial offset is modulated up to the chopping frequency by CHOP3 and filtered out by the NF. Therefore, initial offset does not create any feedback and does not disturb the desired input signal. The NF is synchronized with the chopping clock to filter out the modulated component. In the same manner, the offset of Gm5 is filtered out by the combination of CHOP3 and the NF, enabling accurate ripple sensing at the output of CHOP2. In parallel with the high dc gain path, a feedforward transconductance amplifier (Gm6) is added to bypass the phase shift introduced by the ACFB at the chopping frequency. Gm6 is designed to have the same transconductance as Gm1 to avoid pole-zero doublets. This design prevents any instability introduced by the ACFB in the overall feedback loop. CHOP1 +IN –IN C3 C1 Gm1 CHOP2 C2 Gm3 OUT Gm2 Gm5 Gm6 (= Gm1) NF CHOP3 Gm4 Figure 59. ADA4051-1/ADA4051-2 Chopper Amplifiers Block Diagram The voltage noise density, which is equal to the thermal noise floor dominated by the Gm1, is essentially flat from dc to the chopping frequency because CHOP1 and CHOP2 eliminate the 1/f noise generated in Gm1 and the ACFB does not contribute any additional noise. Although the ACFB suppresses the ripple related to the chopping, there is a remaining voltage ripple. To further suppress the remaining ripple down to a desired level, it is recommended to have a postfilter at the output of the amplifier. The remaining voltage ripple originates from two sources. The first type of ripple is due to the residual ripple associated with the initial offset of the Gm1. It is proportional to the magnitude of the initial offset and creates a spectrum at the chopping frequency (fCHOP). When the amplifier is configured as a unitygain buffer, this ripple has a typical value of 4.9 μV rms and a maximum of 34.7 μV rms. The second type of ripple is due to the intermodulation between the high frequency input signal and the chopping frequency. This ripple depends on the input frequency (fIN) and creates a spectrum at frequencies equal to the difference between the chopping frequency and the input frequency (fCHOP − fIN), as well as at frequencies equal to the summation of the chopping frequency and the input frequency (fCHOP + fIN). The magnitude of the ripple for different input frequencies is shown in Figure 60. 500 MODULATED OUTPUT RIPPLE (µV rms) 400 300 200 100 0 1 2 3 4 5 6 7 8 9 10 INPUT FREQUENCY (kHz) Figure 60. ADA4051-1/ADA4051-2 Modulated Output Ripple vs. Input Frequency Rev. B | Page 15 of 20 08056-063 0 08056-060 ADA4051-1/ADA4051-2 The design architecture of the ADA4051-1/ADA4051-2 specifically targets precision signal conditioning applications requiring accurate and stable performance from dc to 10 Hz bandwidth. In summary, the main features of the ADA4051-1/ ADA4051-2 chopper amplifiers are • • Considerable suppression of the offset-related ripple No affect on the desired input signal as long as its frequency is much lower than the chopping frequency shown in Figure 60 Achievement of low offset similar to a conventional chopper amplifier No introduction of excess noise The ADA4051-1/ADA4051-2 also have internal circuitry that protects the input stage from high differential voltages. This circuitry is composed of internal 1.33 kΩ resistors in series with each input and back-to-back diode-connected N-MOSFET (with a typical VT of 0.7 V for a VCM of 0 V) after these series resistors. With normal negative feedback operating conditions, the ADA4051-1/ ADA4051-2 amplifiers correct their output to ensure that the two inputs are at the same voltage. However, if the device is configured as a comparator or there are unusual operating conditions, the input voltages can be forced to different potentials, which may cause excessive current to flow through the internal diodeconnected N-MOSFETs. Although the ADA4051-1/ADA4051-2 are rail-to-rail input amplifiers, take care to ensure that the potential difference between the inputs does not exceed ±VSY to avert permanent damage to the device. • • The ADA4051-1/ADA4051-2 chopper amplifiers provide a railto-rail input range with a 1.8 V to 5.5 V supply voltage range and 20 μA supply current consumption over the −40°C to +125°C extended industrial temperature range. The gain bandwidth is 125 kHz as a unity-gain stable amplifier up to 100 pF load capacitance. OUTPUT PHASE REVERSAL Although output phase reversal can occur with other amplifiers when the input common-mode voltage range is exceeded, the ADA4051-1/ADA4051-2 amplifiers are designed to prevent any output phase reversal, provided both inputs are maintained approximately within 0.3 V above and below the supply voltages (±VSY ± 0.3 V). With other amplifiers, the outputs may jump in the opposite direction to the supply rail when a common-mode voltage moves outside the common-mode range. This usually occurs when one of the internal stages of the amplifier no longer has sufficient bias voltage across it and subsequently turns off. However, with the ADA4051-1/ADA4051-2 amplifiers, if one or both inputs exceed the input voltage range but remain within the ±VSY ± 0.3 V range, an internal loop opens and the output remains in saturation mode, without phase reversal, until the input voltage is brought back to within the input voltage range limits as shown in Figure 55 and Figure 58. INPUT VOLTAGE RANGE The ADA4051-1/ADA4051-2 have internal ESD protection diodes. These diodes are connected between the inputs and each supply rail to protect the input MOSFETs from an electrical discharge event and are reversed-biased during normal operation. This protection scheme allows voltages as high as approximately 0.3 V beyond the supplies (±VSY ± 0.3 V) to be applied at the input of either terminal without causing permanent damage. If either input exceeds one of the supply rails by more than 0.3 V, these ESD diodes become forward-biased and large amounts of current begin to flow through them. Without current limiting, this excessive current would cause permanent damage to the device. If the inputs are expected to be subject to overvoltage conditions, install a resistor in series with each input to limit the input current to 10 mA maximum. Rev. B | Page 16 of 20 ADA4051-1/ADA4051-2 OUTLINE DIMENSIONS 3.00 2.90 2.80 1.70 1.60 1.50 5 4 3.00 2.80 2.60 1 2 3 0.95 BSC 1.90 BSC 1.30 1.15 0.90 1.45 MAX 0.95 MIN 0.20 MAX 0.08 MIN 10° 5° 0° 0.55 0.45 0.35 121608-A 0.15 MAX 0.05 MIN 0.50 MAX 0.35 MIN SEATING PLANE 0.20 BSC COMPLIANT TO JEDEC STANDARDS MO-178-AA Figure 61. 5-Lead Small Outline Transistor Package [SOT-23] (RJ-5) Dimensions shown in millimeters 2.20 2.00 1.80 1.35 1.25 1.15 2.40 2.10 1.80 5 1 2 4 3 0.65 BSC 1.00 0.90 0.70 1.10 0.80 0.40 0.10 COMPLIANT TO JEDEC STANDARDS MO-203-AA Figure 62. 5-Lead Thin Shrink Small Outline Transistor Package [SC-70] (KS-5) Dimensions shown in millimeters Rev. B | Page 17 of 20 072809-A 0.10 MAX COPLANARITY 0.10 0.30 0.15 SEATING PLANE 0.22 0.08 0.46 0.36 0.26 ADA4051-1/ADA4051-2 3.20 3.00 2.80 3.20 3.00 2.80 PIN 1 IDENTIFIER 8 5 1 5.15 4.90 4.65 4 0.65 BSC 0.95 0.85 0.75 0.15 0.05 COPLANARITY 0.10 0.40 0.25 15° MAX 1.10 MAX 0.23 0.09 0.80 0.55 0.40 100709-B 6° 0° COMPLIANT TO JEDEC STANDARDS MO-187-AA Figure 63. 8-Lead Mini Small Outline Package [MSOP] (RM-8) Dimensions shown in millimeters 3.25 3.00 SQ 2.75 0.60 MAX 0.60 MAX 5 8 0.50 BSC PIN 1 INDICATOR TOP VIEW 2.95 2.75 SQ 2.55 EXPOSED PAD (BOT TOM VIEW) 1.60 1.45 1.30 PIN 1 INDICATOR 4 1 0.90 MAX 0.85 NOM SEATING PLANE 12° MAX 0.70 MAX 0.65 TYP 0.50 0.40 0.30 0.05 MAX 0.01 NOM 1.89 1.74 1.59 Figure 64. 8-Lead Lead Frame Chip Scale Package [LFCSP_VD] 3 mm × 3 mm Body, Very Thin, Dual Lead (CP-8-2) Dimensions shown in millimeters ORDERING GUIDE Model 1 ADA4051-1ARJZ-R2 ADA4051-1ARJZ-R7 ADA4051-1ARJZ-RL ADA4051-1AKSZ-R2 ADA4051-1AKSZ-R7 ADA4051-1AKSZ-RL ADA4051-2ACPZ-R2 ADA4051-2ACPZ-R7 ADA4051-2ACPZ-RL ADA4051-2ARMZ ADA4051-2ARMZ-R7 ADA4051-2ARMZ-RL 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 −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 −40°C to +125°C −40°C to +125°C Package Description 5-Lead SOT-23 5-Lead SOT-23 5-Lead SOT-23 5-Lead SC-70 5-Lead SC-70 5-Lead SC-70 8-Lead LFCSP_VD 8-Lead LFCSP_VD 8-Lead LFCSP_VD 8-Lead MSOP 8-Lead MSOP 8-Lead MSOP Package Option RJ-5 RJ-5 RJ-5 KS-5 KS-5 KS-5 CP-8-2 CP-8-2 CP-8-2 RM-8 RM-8 RM-8 090308-B 0.30 0.23 0.18 0.20 REF FOR PROPER CONNECTION OF THE EXPOSED PAD, REFER TO THE PIN CONFIGURATION AND FUNCTION DESCRIPTIONS SECTION OF THIS DATA SHEET. Branding A0U A0U A0U A0U A0U A0U A2M A2M A2M A2M A2M A2M Z = RoHS Compliant Part. Rev. B | Page 18 of 20 ADA4051-1/ADA4051-2 NOTES Rev. B | Page 19 of 20 ADA4051-1/ADA4051-2 NOTES ©2009–2010 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. D08056-0-1/10(B) Rev. B | Page 20 of 20