AD8231 Analog Devices, AD8231 Datasheet
AD8231
Available stocks
Related parts for AD8231
AD8231 Summary of contents
Page 1
... AD8224 1 Rail-to-rail output. The AD8231 also includes an uncommitted op amp that can be used for additional gain, differential signal driving or filtering. Like the in-amp, the op amp has an auto-zero architecture, rail- to-rail input, and rail-to-rail output. The AD8231 includes a shutdown feature that reduces current to a maximum of 1 μ ...
Page 2
... AD8231 TABLE OF CONTENTS Features .............................................................................................. 1 Applications....................................................................................... 1 Functional Block Diagram .............................................................. 1 General Description ......................................................................... 1 Revision History ............................................................................... 2 Specifications..................................................................................... 3 Absolute Maximum Ratings............................................................ 7 Thermal Resistance ...................................................................... 7 ESD Caution.................................................................................. 7 Pin Configuration and Function Descriptions............................. 8 Typical Performance Characteristics ............................................. 9 Instrumentation Amplifier Performance Curves..................... 9 Operational Amplifier Performance Curves .......................... 12 Performance Curves Valid for Both Amplifiers ..................... 13 REVISION HISTORY 5/07— ...
Page 3
... V = 2.5 V IN− 0 1.1 10||5 100 110 0.05 4.95 28 −0.2 +5.2 AD8231 Unit μV μV/°C μV μV/° ppm/°C ppm/° nV/√Hz nV/√Hz nV/√Hz μV p-p nV/√Hz nV/√Hz nV/√Hz μV p-p GΩ ...
Page 4
... AD8231 Parameter DYNAMIC PERFORMANCE Bandwidth Gain Bandwidth Product 128 Slew Rate OUTPUT CHARACTERISTICS Output Voltage High Output Voltage Low Short-Circuit Current DIGITAL INTERFACE Input Voltage Low Input Voltage High Setup Time to CS high Hold Time after CS high OPERATIONAL AMPLIFIER ...
Page 5
... T = −40° kHz 125° 0 kHz kHz −40° kHz 125° 0 Rev Page AD8231 Min Typ Max Unit 4 15 μV 0.01 0.05 μV/° μV 0.05 0.5 μV/°C ...
Page 6
... AD8231 Parameter DYNAMIC PERFORMANCE Bandwidth Gain Bandwidth Product 128 Slew Rate OUTPUT CHARACTERISTICS Output Voltage High Output Voltage Low Short-Circuit Current DIGITAL INTERFACE Input Voltage Low Input Voltage High Setup Time to CS high Hold Time after CS high OPERATIONAL AMPLIFIER ...
Page 7
... Maximum Power Dissipation 1.5 kV The maximum safe power dissipation for the AD8231 is limited 0 the associated rise in junction temperature (T approximately 130°C, which is the glass transition temperature, the plastic changes its properties. Even temporarily exceeding this temperature limit may change the stresses that the package exerts on the die, permanently shifting the parametric perform- ance of the amplifiers. Exceeding a temperature of 130° ...
Page 8
... PIN INDICATOR S 11 –V (IN-AMP –IN) –INA 2 AD8231 S (IN-AMP +IN) +INA 3 10 OUTA (IN-AMP OUT) TOP VIEW (Not to Scale REF CONNECT Figure 2. 16-Lead LFCSP (Chip Scale) Description No Connect. In-Amp Negative Input. In-Amp Positive Input. No Connect. ...
Page 9
... –10 –20 –30 –40 100 1k 10k 100k FREQUENCY (Hz) Figure 6. Gain vs. Frequency 140 G = +128 120 100 100 1k 10k FREQUENCY (Hz) Figure 7. CMRR vs. Frequency G = +128, 0.4µV/DIV G = +1, 1µV/DIV Figure 8. 0 Noise AD8231 1M 10M 100k 1s/DIV ...
Page 10
... AD8231 100 +128 FREQUENCY (Hz) Figure 9. Voltage Noise Spectral Density vs. Frequency 1000 Hz 1000 900 G = +128 800 700 600 500 400 300 200 100 100 1k FREQUENCY (Hz) Figure 10. Voltage Noise Spectral Density vs. Frequency, 5V MHz 2 ...
Page 11
... V Figure 19. Settling Time vs. Gain for p-p Step 10µs/DIV Figure 20. Settling Time vs. Gain for p-p Step Rev Page AD8231 17.6µs TO 0.01% 21.4µs TO 0.001% 100µs/DIV = 0.001% 0.01% 10 100 1 k GAIN (V/ 0.001% ...
Page 12
... AD8231 OPERATIONAL AMPLIFIER PERFORMANCE CURVES 100 10kΩ 200pF L –20 10 100 1k 10k 100k FREQUENCY (Hz) Figure 21. Open Loop Gain and Phase vs. Frequency, V 100 72° PHASE 10kΩ 200pF L –20 10 100 1k 10k 100k FREQUENCY (Hz) Figure 22 ...
Page 13
... Figure 29. Output Voltage Swing vs. Output Current Rev Page –40°C SOURCE +25°C SOURCE +85°C SOURCE 3 +125°C SOURCE –40°C SINK +25°C SINK 2 +85°C SINK +125°C SINK OUTPUT CURRENT (mA) AD8231 ...
Page 14
... The AD8231 also includes a free operational amplifier. Like the other amplifiers in the AD8231 zero drift, rail-to-rail input, rail-to-rail output architecture. GAIN SELECTION The AD8231’s gain is set by voltages applied to the A0, A1, and A2 pins ...
Page 15
... PCB symbol has the correct dimensions. Space between the leads and thermal pad should be kept as wide as possible for the best bias current performance. Thermal Pad The AD8231 4 mm × LFCSP comes with a thermal pad. This pad is connected internally to −V S left unconnected or connected to the negative supply rail. For high vibration applications, a landing is recommended ...
Page 16
... The extra op amp can be used to provide another gain stage after the in-amp. Because the AD8231 has good offset and noise performance at low gains, applying less gain in the instrumentation amplifier generally has a limited impact on the overall system performance. ...
Page 17
... The outputs of both the AD8231 in-amp and op amp are high impedance in the shutdown state. This feature allows several AD8231s to be multiplexed together without any external switches. Figure 35 shows an example of such a configuration. All the outputs are connected together and only one amplifier is turned time ...
Page 18
... AD8231 OUTLINE DIMENSIONS PIN 1 INDICATOR 12° MAX 1.00 0.85 0.80 ORDERING GUIDE Model Temperature Range AD8231ACPZ-R7 1 −40°C to +125°C 1 AD8231ACPZ-RL −40°C to +125°C 1 AD8231ACPZ-WP −40°C to +125° RoHS Compliant Part. 4.00 BSC SQ 0.60 MAX 0.65 BSC TOP 3.75 VIEW BSC SQ 0.75 0.60 0.50 0.80 MAX 0.65 TYP 0.05 MAX 0.02 NOM ...
Page 19
... NOTES Rev Page AD8231 ...
Page 20
... AD8231 NOTES ©2007 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. D06586-0-5/07(0) Rev Page ...