The CTMU peripheral is a flexible analog module that can be used in conjunction with an ADC to accurately measure capacitance. It contains a constant current source connected to this ADC channel as shown. The CTMU uses a constant current source to calculate the change in capacitance and the time difference between different events.
Compared to CVD, CTMU provides faster response speed.Because it has multiple different current source ranges.This will help to charge the analog channel at a faster speed ,thereby improving the response time of the capacitive touch sensing system.
CTMU peripherals for capacitive touch sensing applications are implemented using the formula I × T = C × V. Among them: I is the constant current source of CTMU, T is the fixed period of CTMU charging capacitive touch sensor, C is the capacitance of capacitive touch sensor, and V is the voltage of capacitive touch sensor (read by ADC).
