To achieve the most accurate current sense value,
TI recommends to filter the SNS output. There are
two methods of filtering:
- Low-Pass RC filter between the SNS pin and the
ADC input. This filter is illustrated in Figure 10-1 with typical values for the resistor and capacitor. The
designer must select a CSNS capacitor value based on system
requirements. A larger value will provide improved filtering but a smaller value
will allow for faster transient response.
- The ADC and microcontroller can also be used for
filtering. TI recommends that the ADC collects
several measurements of the SNS output. The median
value of this data set must be considered as the
most accurate result. By performing this median
calculation, the microcontroller can filter out
any noise or outlier data.