Can I connect an ADC to the output of the differential amplifier in the MAX9925?
A:
The OUT in the MAX9925 pin is intended help configure a gain for the difference amplifier via negative feedback. If you are looking to connect the output of the differential amplifier to external circuitry such as an ADC, we recommend to buffer the OUT pin because depending on the input impedance of the ADC topology, loading may be an issue.
- The differential amplifier is required to be precise. In scenarios when the signal from the sensor is weak or noisy, having a load at the output of the differential amplifier may hinder its ability to accurately toggle the comparator when required. This may result in skipped cycles.
- The adaptive peak detector relies on an accurate signal from the differential amplifier in order to set the threshold for the upcoming cycle. Having a considerable load at OUT may not allow the MAX9925 to set the optimum threshold voltage for the comparator for the following cycle.