SNVSC83B September 2022 – February 2023 TPSM365R3 , TPSM365R6
PRODUCTION DATA
The TPSM365Rx uses the internal LDO output and the VCC pin for all internal power supply. The VCC pin draws power either from the VIN (in adjustable output variants) or the BIAS (in fixed-output variants). In the fixed output variants, after the TPSM365Rx is active but has yet to regulate, the VCC rail continues to draw power from the input voltage, VIN, until the BIAS voltage reaches > 3.15 V (or when the device has reached steady-state regulation post the soft start). The VCC rail typically measures 3.15 V in both adjustable and fixed output variants. To prevent unsafe operation, VCC has an undervoltage lockout, which prevents switching if the internal voltage is too low. See VVCC-UVLO and VVCC-UVLO-HYST in GUID-XXXXXXXX-SF0T-XXXX-XXXX-000000280921.html#GUID-XXXXXXXX-SF0T-XXXX-XXXX-000000280921. During start-up, VCC momentarily exceeds the normal operating voltage until VVCC-UVLO is exceeded, then drops to the normal operating voltage. Note that these undervoltage lockout values, when combined with the LDO dropout, drives the minimum input voltage rising and falling thresholds.