JAJSHA3K December 2012 – May 2019 TPS50301-HT
PRODUCTION DATA.
The device uses the lower voltage of the internal voltage reference or the SS/TR pin voltage as the reference voltage and regulates the output accordingly. A capacitor on the SS/TR pin to ground implements a slow-start time. The device has an internal pullup current source of 5 mA that charges the external slow-start capacitor. Equation 7 shows the calculations for the slow-start time (Tss, 10% to 90%) and slow-start capacitor (Css). The voltage reference (Vref) is 0.795 V and the slow-start charge current (Iss) is 2.5 μA.
When the input UVLO is triggered, the EN pin is pulled below 1.032 V, or a thermal shutdown event occurs the device stops switching and enters low current operation. At the subsequent power-up, when the shutdown condition is removed, the device does not start switching until it has discharged its SS/TR pin to ground ensuring proper soft-start behavior.