Laboratory instrumentation amplifier that can accommodate high impedance and high bandwidth and has a 16 bit 1MSPS ADC

D

DrM

Well-known member
This is to announce a new instrumentation board for Teensy 4.x (and other Arduino type boards with SPI interfaces).

This is an instrumentation amplifier input board that can provide high bandwidth measurements for a high impedance source. The board has an all differential signal path and a 16 bit 1MSPS ADC. The inputs are bipolar with selectable impedance 100K, 10M and 1T. We include kicad files, fab files, a spice model, a teensy/arduino sketch with a header-only library for the MCP33131D ADC and a user interface written in python. Traditionally, In Amps are low bandwidth devices. We beat that back in this design based on more recently available op amps.

The full posting and repo can be seen here: In Amp with 16 bit 1MSPS ADC for Teensy and Arduino

Here is a picture of the board with its power supply and connected to a controller card based on the Teensy 4. All of the boards are available in github, links are in the readme. The BOM for the In Amp is about $36 at Digikey at this writing.


InAmpSetup.p800.jpg
 
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I think the inputs are CMOS, not bipolar, according to the description it uses a CMOS ADA4510-2 input stage?
 
Yes but that is a different bipolar. The input range is -4V to +4V on each side of the differential pair. Many In Amp boards and chips have unipolar inputs, 0 to 4V for instance, and more so in the MCU world where they try to get aways with single rails. For science you almost always want the range to go past 0. Hence bipolar inputs is a nice feature and one that is too often omitted nowadays.
 
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