ZHCSS16 april 2023 TPS62902-Q1
PRODUCTION DATA
With the SS/TR pin, the user can adjust the soft-start behavior or track an external voltage source (see Section 8.3.4.1 for operation details).
The internal soft-start circuitry controls the output voltage slope during start-up. This avoids excessive inrush current and makes sure there is a controlled output voltage rise time. The soft-start circuitry also prevents unwanted voltage drops from high impedance power sources or batteries. When EN is set high to start operation, the device starts switching after the start-up delay, while the internal reference, and hence VO, rises with a slope controlled by the 2.5μA (typical) ISS current source and an external capacitor connected to the SS/TR pin and the 2.5μA (typical) ISS current source.
If the device is set to shut down (EN = GND), undervoltage lockout, or thermal shutdown, an internal resistor pulls the SS/TR pin down to make sure there is a proper low level. Returning from those states causes a new start-up sequence as set by the SS/TR connection.