AD8556ARZ Analog Devices Inc, AD8556ARZ Datasheet
AD8556ARZ
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AD8556ARZ Summary of contents
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FEATURES EMI filters at input pins Specified from −40°C to +140°C Low offset voltage: 10 μV maximum Low input offset voltage drift: 65 nV/°C maximum High CMRR minimum Digitally programmable gain and output offset voltage Programmable output clamp ...
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AD8556 TABLE OF CONTENTS Features .............................................................................................. 1 Applications....................................................................................... 1 Functional Block Diagram .............................................................. 1 Revision History ............................................................................... 2 General Description ......................................................................... 3 Specifications..................................................................................... 4 Electrical Specifications............................................................... 4 Absolute Maximum Ratings............................................................ 6 Thermal Resistance ...................................................................... 6 ESD Caution.................................................................................. 6 Pin Configurations ...
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GENERAL DESCRIPTION The AD8556 is a zero-drift, sensor signal amplifier with digitally programmable gain and output offset. Designed to easily and accurately convert variable pressure sensor and strain bridge outputs to a well-defined output voltage range, the AD8556 accurately amplifies ...
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AD8556 SPECIFICATIONS ELECTRICAL SPECIFICATIONS VDD = 5.0 V, VSS = 0 2 Table 1. Parameter INPUT STAGE Input Offset Voltage Input Offset Voltage Drift Input Bias Current Input Offset Current Input Voltage Range Common-Mode ...
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Parameter DYNAMIC PERFORMANCE Gain Bandwidth Product Output Buffer Slew Rate Settling Time NOISE PERFORMANCE Input Referred Noise Low Frequency Noise Total Harmonic Distortion DIGITAL INTERFACE Input Current DIGIN Pulse Width to Load 0 DIGIN Pulse Width to Load 1 Time ...
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AD8556 ABSOLUTE MAXIMUM RATINGS Table 2. Parameter Rating Supply Voltage 6 V Input Voltage VSS − 0 VDD + 0 Differential Input Voltage ±5.0 V Output Short-Circuit Duration to Indefinite VSS or VDD Storage Temperature Range ...
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PIN CONFIGURATIONS AND FUNCTION DESCRIPTIONS VDD 1 AD8556 FILT/DIGOUT 2 TOP VIEW DIGIN 3 (Not to Scale) VNEG 4 Figure 2. 8-Lead SOIC_N Pin Configuration Table 4. Pin Function Descriptions Pin No. SOIC_N LFCSP_VQ Mnemonic 1 VDD 2 2 FILT/DIGOUT ...
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AD8556 TYPICAL PERFORMANCE CHARACTERISTICS N: 363 100 MEAN: –0.389938 SD: 1.65684 –10 – (µV) OS Figure 4. Input Offset Voltage Distribution 2.0 1.5 1.0 0.5 0 –0.5 –1.0 –1.5 –2.0 –2.5 –3.0 ...
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I – (V) CM Figure 10. Input Bias Current at VPOS, VNEG vs. Common-Mode Voltage 0.8 0.6 0.5 0.3 0.2 0 –0.2 –0.3 –0.5 –0.6 –0.8 –50 ...
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AD8556 120 100 1k 10k FREQUENCY (Hz) Figure 16. CMRR vs. Frequency 120 80 0 100 1k 10k FREQUENCY (Hz) Figure 17. CMRR vs. Frequency 145 135 GAIN = 1280 125 115 105 95 GAIN = 70 ...
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TIME (1s/DIV) Figure 22. Low Frequency Input Voltage Noise (0 Hz) GAIN = 1280 60 40 GAIN = 10k 100k FREQUENCY (Hz) Figure 23. Closed-Loop Gain ...
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AD8556 1.000 SOURCE 0.100 0.010 0.001 0.01 0.10 LOAD CURRENT (mA) Figure 28. Output Voltage to Supply Rail vs. Load Current 15 12 SINK –3 –6 SOURCE 5V –9 –12 –15 –75 –50 –25 0 ...
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V = 2.7V TO 2.5V SY 120 100 0.01 0 FREQUENCY (kHz) Figure 34. PSRR vs. Frequency T 2 TIME (100µs/DIV) Figure 35. Small Signal Response 0.1 μF and ...
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AD8556 OUT CH1 50.0mV CH2 2.00V M 1.00µs Figure 40. Negative Overload Recovery (Gain = 70 OUT 0V 2 CH1 50.0mV CH2 2.00V M 1.00µs Figure 41. Positive ...
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FREQUENCY (Hz) Figure 46. THD vs. Frequency V = ±2. 10k 20k Rev Page AD8556 ...
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AD8556 THEORY OF OPERATION A1, A2, R1, R2, R3, P1, and P2 form the first gain stage of the differential amplifier. A1 and A2 are auto-zeroed op amps that minimize input offset errors. P1 and P2 are digital potentiometers, guaranteed ...
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GAIN VALUES Table 5. First Stage Gain vs. First Stage Gain Code First Stage First Stage Gain Code Gain Code First Stage Gain 0 4.000 32 1 4.015 33 2 4.030 34 3 4.045 35 4 4.060 36 5 4.075 ...
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AD8556 OPEN WIRE FAULT DETECTION The inputs to A1 and A2, VNEG and VPOS, each have a com- parator to detect whether VNEG or VPOS exceeds a threshold voltage, nominally VDD − 2 (VNEG > VDD − 2.0 ...
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WAVEFORM CODE 0 Table 9. Timing Specifications Timing Parameter Description t Pulse width for loading 0 into shift register w0 t Pulse width for loading 1 into shift register w1 t Width between pulses ...
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AD8556 Initial State Initially, all the polysilicon fuses are intact. Each parameter has the value 0 assigned (see Table 11). Table 11. Initial State Before Programming Second Stage Gain Code = 0 Second Stage Gain = 17.5 First stage gain ...
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Parity Error Detection A parity check is used to determine whether the programmed data of an AD8556 is valid, or whether data corruption has occurred in the nonvolatile memory. Figure 50 shows the schematic implemented in the AD8556. VA0 to ...
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AD8556 Read Mode The values stored by the polysilicon fuses can be sent to the FILT/DIGOUT pin to verify correct programming. Normally, the FILT/DIGOUT pin is only connected to the second gain stage output via RF. During read mode, however, ...
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Important: Once a programming attempt is made for any fuse, there should be no further attempt to blow that fuse fuse does not program to the expected state, discard the unit. The expected incidence rate of attempted but ...
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AD8556 EMI/RFI PERFORMANCE Real-world applications must work with ever increasing radio/magnetic frequency interference (RFI and EMI). In situations where signal strength is low and transmission lines are long, instrumentation amplifiers, such as the AD8556, are needed to extract weak, small ...
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To show the benefits that the AD8556 brings to new applications where EMI/RFI signals are present, a part was programmed with a gain of 70 and a dc offset of 2 produce a VOUT ...
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... ORDERING GUIDE Model Temperature Range AD8556ARZ 1 −40°C to +140°C 1 AD8556ARZ-REEL −40°C to +140°C 1 AD8556ARZ-REEL7 −40°C to +140°C AD8556ACPZ-R2 1 −40°C to +140°C 1 AD8556ACPZ-REEL −40°C to +140°C 1 AD8556ACPZ-REEL7 −40°C to +140° RoHS Compliant Part. ...
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NOTES Rev Page AD8556 ...
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AD8556 NOTES ©2005–2007 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. D05448-0-12/07(A) Rev Page ...