ad8251nbsp Analog Devices, Inc., ad8251nbsp Datasheet
ad8251nbsp
Related parts for ad8251nbsp
ad8251nbsp Summary of contents
Page 1
... FREQUENCY (Hz) Figure 2. Gain vs. Frequency Low High Mil Low Cost Voltage Grade Power 1 1 AD623 AD628 AD620 AD627 1 AD629 AD621 AD8553 AD524 AD526 AD624 www.analog.com ©2007 Analog Devices, Inc. All rights reserved. ® 100M Digital Gain 1 AD8231 AD8250 1 AD8555 1 AD8556 1 AD8557 ...
Page 2
AD8251 TABLE OF CONTENTS Features .............................................................................................. 1 Applications....................................................................................... 1 General Description ......................................................................... 1 Functional Block Diagram .............................................................. 1 Revision History ............................................................................... 2 Specifications..................................................................................... 3 Timing Diagram ........................................................................... 5 Absolute Maximum Ratings............................................................ 6 Maximum Power Dissipation ..................................................... 6 ESD Caution.................................................................................. 6 ...
Page 3
SPECIFICATIONS +V = +15 V, −V = − REF Table 2. Parameter COMMON-MODE REJECTION RATIO (CMRR) CMRR with 1 kΩ Source Imbalance ...
Page 4
AD8251 Parameter Settling Time 0.001 Slew Rate Total Harmonic Distortion + Noise GAIN Gain Range Gain ...
Page 5
Parameter POWER SUPPLY Operating Range Quiescent Current Quiescent Current, −I S Over Temperature TEMPERATURE RANGE Specified Performance 1 Add time for the output to slew and settle to calculate the total time for a gain change. TIMING DIAGRAM ...
Page 6
AD8251 ABSOLUTE MAXIMUM RATINGS Table 3. Parameter Supply Voltage Power Dissipation Output Short-Circuit Current Common-Mode Input Voltage Differential Input Voltage Digital Logic Inputs Storage Temperature Range 2 Operating Temperature Range Lead Temperature (Soldering 10 sec) Junction Temperature θ (4-Layer JEDEC ...
Page 7
PIN CONFIGURATION AND FUNCTION DESCRIPTIONS Table 4. Pin Function Descriptions Pin No. Mnemonic 1 −IN 2 DGND 3 − OUT REF 10 +IN –IN + DGND ...
Page 8
AD8251 TYPICAL PERFORMANCE CHARACTERISTICS T @ 25° +15 V, −V = − 2700 2400 2100 1800 1500 1200 900 600 300 0 –120 –90 –60 – CMRR (µV/V) Figure 6. Typical ...
Page 9
Figure 12. 0 RTI Voltage Noise 100 1k FREQUENCY (Hz) Figure 13. Current Noise Spectral Density vs. Frequency 140pA/DIV Figure ...
Page 10
AD8251 140 120 100 100 1k 10k FREQUENCY (Hz) Figure 18. CMRR vs. Frequency 140 120 100 ...
Page 11
OUTPUT VOLTAGE (V) Figure 24. Gain Nonlinearity kΩ, 2 kΩ, 600 Ω ...
Page 12
AD8251 +V S –0.2 –0.4 –0.6 –0.8 –1.0 –40°C +25°C –40°C +1.0 +0.8 +0.6 +0.4 +0.2 – SUPPLY VOLTAGE (±V Figure 30. Output Voltage Swing vs. Supply Voltage –0.2 ...
Page 13
TO 0.01% 600ns TO 0.001% 0.002%/DIV 2µs/DIV Figure 36. Large Signal Pulse Response and Settling Time kΩ L 5V/DIV 376ns TO 0.01% 640ns TO 0.001% 0.002%/DIV 2µs/DIV Figure 37. Large Signal Pulse ...
Page 14
AD8251 25mV/DIV Figure 42. Small Signal Response 1200 1000 SETTLED TO 0.001% 800 600 SETTLED TO 0.01% 400 200 STEP SIZE (V) Figure 43. Settling Time vs. Step Size, ...
Page 15
– –90 –95 –100 –105 –110 –115 –120 10 100 1k 10k FREQUENCY (Hz) Figure 48. Total Harmonic Distortion vs. Frequency, ...
Page 16
... The AD8251 is a monolithic instrumentation amplifier based on the classic, three op amp topology, as shown in Figure 49 fabricated on the Analog Devices, Inc. proprietary iCMOS process that provides precision, linear performance, and a robust digital interface. A parallel interface allows users to digitally program gains and 8. Gain control is achieved by switching resistors in an internal, precision, resistor array (as shown in Figure 49) ...
Page 17
Table 5. Truth Table Logic Levels for Transparent Gain Mode −V Low Low S −V Low High S −V High Low S −V High High S Latched Gain Mode Some applications have multiple programmable devices such as ...
Page 18
AD8251 POWER SUPPLY REGULATION AND BYPASSING The AD8251 has high PSRR. However, for optimal performance, a stable dc voltage should be used to power the instrumentation amplifier. Noise on the supply pins can adversely affect per- formance all ...
Page 19
REFERENCE TERMINAL The reference terminal, REF one end kΩ resistor (see Figure 49). The instrumentation amplifier output is referenced to the voltage on the REF terminal; this is useful when the output signal needs to ...
Page 20
AD8251 +15V 0.1µ +IN AD8251 – 0.1µF –15V Figure 56. RFI Suppression Values of R and C should be chosen to minimize RFI. C Mismatch between the R × the ...
Page 21
APPLICATIONS DIFFERENTIAL OUTPUT In certain applications necessary to create a differential signal. High resolution analog-to-digital converters often require a differential input. In other cases, transmission over a long distance can require differential signals for better immunity to interference. ...
Page 22
AD8251 DATA ACQUISITION The AD8251 makes an excellent instrumentation amplifier for use in data acquisition systems. Its wide bandwidth, low distortion, low settling time, and low noise enable it to condition signals in front of a variety of 16-bit ADCs. ...
Page 23
OUTLINE DIMENSIONS 3.10 3.00 2.90 PIN 1 0.95 0.85 0.75 0.15 0.05 ORDERING GUIDE Model Temperature Range 1 AD8251ARMZ –40°C to +85°C 1 AD8251ARMZ-RL –40°C to +85°C 1 AD8251ARMZ-R7 –40°C to +85°C 1 AD8251-EVALZ RoHS Compliant Part. ...
Page 24
... AD8251 NOTES ©2007 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. D06287-0-5/07(0) Rev Page ...