ZHCS429J March 2012 – November 2021 UCD3138
PRODUCTION DATA
Use low ESL and ESR ceramic capacitors on ADC pins to decouple with SGND. The capacitor value is selected such that the cut-off frequency is at least one tenth the sampling frequency if there is no dynamic requirement. This can help reduce noise coupled during signal transmission.
ADC input is a single-ended signal. If the sensing trace is long, move it away from radiation sources and add ground shielding between the signal and radiation sources. If there exists a resistor between signal output and ADC input, the resistor should be located close to the ADC pin. The resistance needs to be less than 1 kΩ.
For example, the sampling frequency is 10 kHz. The cut off frequency of LPF is 1 kHz. With a 1-kΩ equivalent resistor, select a 0.15-μF capacitor.