SLUSFL7 August 2024 LMR51606-Q1 , LMR51610-Q1
PRODUCTION DATA
The system undervoltage 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. Equation 13 can be used to determine the VIN UVLO level.
The EN rising threshold (VEN(R)) for LMR516xx-Q1 is set to be 1.227V (typical). Choose a value of 200kΩ for RENB to minimize input current from the supply. If the desired VIN rising UVLO level is at 6.0V (typical), then the value of RENT can be calculated using Equation 14:
The above equation yields a value of 778kΩ, a standard value of 768kΩ is selected. The resulting VIN falling UVLO threshold, equal to 4.84V, can be calculated by Equation 15 where EN falling threshold (VEN(F)) for LMR516xx-Q1 is set to be 1.0V (typical).