SLVSDG6B May 2016 – April 2021 TPS54302
The undervoltage lockout (UVLO) set point can be adjusted using the external-voltage divider network of R4 and R5. The R4 resistor is connected between the VIN and EN pins of the TPS54302 device. The R5 resistor is connected between the EN and GND pins. The UVLO has two thresholds, one for power up when the input voltage is rising and one for power down or brownouts when the input voltage is falling. For the example design, the minimum input voltage is 8 V, so the start voltage threshold is set to 6.74 V and the stop voltage threshold is set to 5.83 V. Use Equation 1 and Equation 2 to calculate the values for the upper and lower resistor values of R4 and R5.