Features: `Digitally programmable gain
G= 1, 2, 4, 8, 16, 32, 64, 128
Software or pin programmable
`Excellent temperature performance
Specified from −40°C to +125°C
50 nV/°C max input offset drift
10 ppm/°C max gain drift
`Excellent dc performance
122 dB min CMR, G = 128
25 V max input offset voltage
100 pA max bias current
0.7 uV p-p (0.1 Hz to 10 Hz)
`Good ac performance
Gain Bandwidth Product 1 MHz
Slew Rate 0.7 V/s
`Rail-to-rail input and output
`Shutdown/Multiplex
`Additional uncommitted op amp
`Supply range: 3.0V to 5.5VApplication·Pressure and Strain Transducers
·Thermocouples and RTDs
·Programmable Instrumentation
·Industrial Controls
·Weigh ScalesPinout
Specifications
| Parameter |
Rating |
| Supply Voltage |
|
| Internal Power Dissipation |
|
| Output Short Circuit Current |
|
| Input Voltage (Common-Mode) |
|
| Differential Input Voltage |
|
| Storage Temperature |
65°C to +150°C |
| Operational Temperature Range |
40°C to +125°C |
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 may affect device reliability.DescriptionThe AD8231 is a low drift, rail to rail, instrumentation amplifier with software programmable gains of 1, 2, 4, 8, 16, 32, 64 or 128. The gains are programmed via digital logic or pin strapping.
The AD8231 is ideal for applications that require precision performance over a wide temperature range, such as industrial temperature sensing and data logging. Because the gain setting resistors are internal, maximum gain drift is only 10 ppm/ºC. Because of the autozero input stage, maximum input offset is 25 uV and maximum input offset drift is just 50 nV/ºC. CMRR is also guaranteed over temperature: 80 dB for G=1, increasing to 122 dB at a gain of 128. Voltage noise is just 0.7 uV p-p (0.01 Hz to 10 Hz).
The AD8231 also includes an uncommitted op amp which can be used for additional gain, differential signal driving or filtering. Like the in amp, the op amp has an autozero architecture, rail to rail input, and rail to rail output.
The AD8231 includes a shutdown feature that reduces current to 1 uA and makes the amplifier output high impedance. This allows easy multiplexing of multiple amplifiers without additional switches.
The AD8231 is specified over the extended industrial temperature range of -40°C to +125°C. It is available in a 4mm x 4mm 16-Lead LFCSP (Chip Scale) package.
AD8231 Data Sheet
