SWCU191 February 2022 CC1311P3 , CC1311R3 , CC2651P3 , CC2651R3 , CC2651R3SIPA
The AUX Current Source (ISRC) module has the following features:
The primary application for the ISRC peripheral is capacitive touch sensing, where it is used together with the COMPA and TDC peripherals. In this application, ISRC drives an internal reference voltage for COMPA, nominally 0.8 V, while charging the capacitance connected to the COMPA input. The time from start of charging until the COMPA output goes high is measured using the TDC.
ISRC is not supported in all devices. Please consult the device datasheet.
Figure 20-20 shows the ISRC analog connections and digital control. Proper Reference DAC control and connections are described in Section 20.1.