AD8655 Analog Devices, AD8655 Datasheet
AD8655
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AD8655 Summary of contents
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... The AD8655/AD8656 are the industry’s lowest noise, precision CMOS amplifiers. They leverage the Analog Devices DigiTrim® technology to achieve high dc accuracy. The AD8655/AD8656 provide low noise (2.7 nV/√ kHz), low THD + N (0.0007%), and high precision performance (250 μV max over low voltage applications. The ability ...
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... AD8655/AD8656 TABLE OF CONTENTS Specifications..................................................................................... 3 Absolute Maximum Ratings............................................................ 5 ESD Caution.................................................................................. 5 Typical Performance Characteristics ............................................. 6 Theory of Operation ...................................................................... 15 Applications..................................................................................... 16 Input Overvoltage Protection ................................................... 16 Input Capacitance....................................................................... 16 REVISION HISTORY 9/11—Rev Rev. B Changes to Features Section............................................................ 1 Updated Outline Dimensions ....................................................... 19 Changes to Ordering Guide .......................................................... 19 Added Automotive Products Section .......................................... 19 6/05—Rev Rev. A Added AD8656 ...
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... THD + kΩ kHz GBP kΩ 0.1 step Rev Page AD8655/AD8656 Min Typ Max 50 250 550 0.4 2 500 10 500 100 = 0 V 100 110 ...
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... AD8655/AD8656 25°C, unless otherwise specified Table 2. Parameter INPUT CHARACTERISTICS Offset Voltage Offset Voltage Drift Input Bias Current Input Offset Current Input Voltage Range Common-Mode Rejection Ratio Large Signal Voltage Gain OUTPUT CHARACTERISTICS Output Voltage High Output Voltage Low ...
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... Table 4. Package Type 8-Lead MSOP (RM) 8-Lead SOIC (R) 1 θ is specified for worst-case conditions; that is, θ JA soldered in the circuit board for surface-mount packages. Rev Page AD8655/AD8656 1 θ θ Unit JA JC 210 45 °C/W 158 43 ° ...
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... AD8655/AD8656 TYPICAL PERFORMANCE CHARACTERISTICS –150 –100 – (μV) OS Figure 5. Input Offset Voltage Distribution 150.0 100.0 50.0 0.0 –50.0 –100.0 –150.0 – TEMPERATURE (°C) Figure 6. Input Offset Voltage vs. Temperature 0.2 0.4 0.6 0.8 1.0 |TCV | (μV/°C) OS Figure 7. |TCV | Distribution ...
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... Figure 11. Supply Current vs. Temperature 2500 V = ±2.5V S 2000 1500 V OH 1000 500 100 150 CURRENT LOAD (mA) Figure 12. AD8655 Output Voltage to Supply Rail vs. Current Load 10000 1000 100 0 CURRENT LOAD (mA) Figure 13. AD8656 Output Swing vs. Current Load 4.996 4.994 4 ...
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... AD8655/AD8656 110.00 107.00 104.00 101.00 98.00 95.00 92.00 – TEMPERATURE (°C) Figure 17. Large Signal CMRR vs. Temperature 100 +PSRR 80 –PSRR 100 1k 10k 100k FREQUENCY (Hz) Figure 18. Small Signal PSSR vs. Frequency 110. ±2.5V S 108.00 106.00 104.00 102.00 100.00 – TEMPERATURE (°C) Figure 19. Large Signal PSSR vs. Temperature V = ± ...
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... Figure 25. Closed-Loop Gain vs. Frequency –45 = 11.5pF –90 –135 –180 –225 10M 100M 100 150 V = ±2. Ω 47pF L 10M 100M Rev Page AD8655/AD8656 10k 100k 1M FREQUENCY (Hz) Figure 26. Maximum Output Swing vs. Frequency ±2. 100pF L GAIN = + ...
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... AD8655/AD8656 ±2. 200mV – + 100 150 200 CAPACITANCE (pF) Figure 29. Small Signal Overshoot vs. Load Capacitance T 300mV ±2.5V OUT 300mV IN GAIN = –10 RECOVERY TIME = 240ns –2.5V 400ns/DIV Figure 30. Negative Overload Recovery Time ...
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... Figure 36. Supply Current vs. Temperature 1400 V = ±1.35V S 1200 1000 V OH 800 600 V 400 200 LOAD CURRENT (mA) Figure 37. AD8655 Output Voltage to Supply Rail vs. Load Current V = ±1.35V S 1.2 1.4 1.6 100 150 OL 80 100 120 Rev Page AD8655/AD8656 10000 1000 100 ...
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... AD8655/AD8656 OUT 2 20 μ s/DIV Figure 41. No Phase Reversal V = ±1.35V 50pF L GAIN = +1 2 TIME (10μs/DIV) Figure 42. Large Signal Response T 2 TIME (1μs/DIV) Figure 43. Small Signal Response ±1.35V 50pF Figure 44 ...
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... V = ±1.35V 50mV 1MΩ 47pF L 1M 10M 100M Rev Page AD8655/AD8656 V = ±1.35V 11.5pF LOAD PHASE MARGIN = 54° 10k 100k 1M 10M FREQUENCY (Hz) Figure 50. Open-Loop Gain and Phase vs. Frequency 90.00 80.00 – TEMPERATURE (°C) Figure 51 ...
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... AD8655/AD8656 3.0 2 1.35V 2. LOAD 1.5 1.0 0.5 0 10k 100k FREQUENCY (Hz) Figure 53. Maximum Output Swing vs. Frequency 1000 V = ±1.35V S 100 G = +100 0.1 100 1k 10k 100k FREQUENCY (Hz) Figure 54. Output Impedance vs. Frequency –100 –120 –140 1M 10M 10M 100M Rev Page 10k Ω ...
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... The open- loop gain of the AD8655/AD8656 with a load of 10 kΩ is typically 110 dB. The AD8655/AD8656 can be used in any precision op amp application ...
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... See the Driving Capacitive Loads section. DRIVING CAPACITIVE LOADS Although the AD8655/AD8656 can drive capacitive loads up to 500 pF without oscillating, a large amount of ringing is present when operating the part with input frequencies above 100 kHz. ...
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... Data Sheet THD Readings vs. Common-Mode Voltage Total harmonic distortion of the AD8655/AD8656 is well below 0.0007% with a load of 1 kΩ. This distortion is a function of the circuit configuration, the voltage applied, and the layout, in addition to other factors. +2.5V – AD8655 + –2. Figure 59. THD + N Test Circuit ...
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... Poor PC board layout, contaminants, and the board insulator material can create leakage currents that are much larger than the input bias current of the AD8655/AD8656. Any voltage differential between the inputs and nearby traces creates leakage currents through the PC board insulator, for example, 1 V/100 GΩ ...
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... AD8655ARZ −40°C to +125°C AD8655ARZ-REEL −40°C to +125°C AD8655ARZ-REEL7 −40°C to +125°C AD8655ARMZ-REEL −40°C to +125°C AD8655ARMZ −40°C to +125°C AD8656ARZ −40°C to +125°C AD8656ARZ-REEL −40°C to +125°C AD8656ARZ-REEL7 −40°C to +125°C AD8656ARMZ − ...
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... AD8655/AD8656 NOTES ©2005–2011 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. D05304-0-9/11(B) Rev Page Data Sheet ...