SNVSCM8A October 2023 – December 2023 TPS3762
PRODUCTION DATA
The time delay (tCTS) can be programmed by connecting a capacitor between CTS pin and GND.
The relationship between external capacitor CCTS_EXT (typ) and the time delay tCTS (typ) is given by Equation 4.
RCTS = is in kilo ohms (kΩ)
CCTS_EXT = is given in microfarads (μF)
tCTS = is the sense time delay (ms)
The sense delay varies according to three variables: the external capacitor (CCTS_EXT), CTS pin internal resistance (RCTS) provided in Electrical Characteristics, and a constant. The minimum and maximum variance due to the constant is show in Equation 5 and Equation 6:
The recommended maximum sense delay capacitor for the TPS3762 is limited to 10 μF as this makes sure enough time for the capacitor to fully discharge when a voltage fault occurs. Also, having a too large of a capacitor value can cause very slow charge up (rise times) and system noise can cause the internal circuit to trip earlier or later near the threshold. This leads to variation in time delay where it can make the delay accuracy worse in the presence of system noise.
* Leakages on the capacitor can effect accuracy of sense time delay.