ZHCSLU2C December 2021 – August 2024 LM63440-Q1 , LM63460-Q1
PRODUCTION DATA
VCC is the output of the internal LDO subregulator used to supply the control circuits of the LM634x0-Q1. The nominal VCC voltage is 3.3V. The BIAS pin is the input to the internal LDO. This input can be connected to VOUT to provide the lowest possible input supply current. If the BIAS voltage is less than 3.1V, VIN1 and VIN2 directly power the internal LDO.
To prevent unsafe operation, VCC has UVLO protection that prevents switching if the internal voltage is too low. See VCC-UVLO and VCC-UVLO-HYST in the Electrical Characteristics. Note that these UVLO levels and the dropout voltage of the LDO are used to derive the minimum VIN_OPERATE and VIN_OPERATE_H values.