Known issues when connecting sensors to the ADMW1001?

What are some issues to be aware of when connecting sensors to the ADMW1001?

[edited by: LiamR at 9:47 PM (GMT 0) on 11 Jul 2019]
  • +1
    •  Analog Employees 
    on Jul 11, 2019 9:51 PM

    For most sensors it is recommended to keep the input buffers enabled as the majority of sensors are not low-Z sources and should be isolated from the sampling currents of the ADC. All default configurations turn the buffers on regardless of PGA gain. The input buffers are not rail-to-rail input and care must be taken to keep the inputs within

    RSENSE_BIAS is typically configured to provide a 100mV reference at the low side of RSENSE. It can sink a few hundred µA, beyond this amount a shunt resistor to GND of between 500 to 1 kΩ is recommended at this node.

    The input differential voltage is limited to:

    Anti-aliasing filtering and overvoltage protection resistors are useful but care should be taken not to produce an offset due to leakage currents. Thermocouple inputs are particularly sensitive as the DV/DT is in the microvolts.

    TC_BIAS can be used to keep the thermocouple inputs biased to mid-supply but this is a very weak divider and cannot source or sink current (~ 10 µA at most)