JAJSFC9B September 2017 – June 2018 TPS560430
UNLESS OTHERWISE NOTED, this document contains PRODUCTION DATA.
The system under voltage lockout (UVLO) is adjusted using the external voltage divider network of RENT and RENB. The UVLO has two thresholds, one for power up when the input voltage is rising and one for power down or brown outs when the input voltage is falling. The following equation can be used to determine the VIN UVLO level.
The EN rising threshold (VENH) for TPS560430 is set to be 1.23 V (typical). Choose the value of RENB to be 200 kΩ to minimize input current from the supply. If the desired VIN UVLO level is at 6.0 V, then the value of RENT can be calculated using Equation 14:
The above equation yields a value of 775.6 kΩ, a standard value of 768 kΩ is selected. The resulting falling UVLO threshold, equals 5.3 V, can be calculated by Equation 15, where EN hysteresis voltage, VEN_HYS, is 0.13 V (typical).