SLVSF00 January 2019 TPS54560B
PRODUCTION DATA.
The L (UVLO) can be adjusted using an external voltage divider on the EN pin of the TPS54560B. 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 supply must turn on and start switching once the input voltage increases above 6.5 V (UVLO start). After the regulator starts switching, it should continue to do so until the input voltage falls below 5 V (UVLO stop).
Programmable UVLO threshold voltages are set using the resistor divider of RUVLO1 and RUVLO2 between VIN and GND, connected to the EN pin. Equation 40 and Equation 41 calculate the resistance values necessary. For the example application, a 442-kΩ resistor between VIN and EN (RUVLO1) and a 90.9-kΩ resistor between EN and GND (RUVLO2) are required to produce the 6.5-V and 5-V start and stop voltages.