ZHCSK92E September 2019 – March 2022 TPS25840-Q1 , TPS25842-Q1
PRODUCTION DATA
The system enable and undervoltage lockout (UVLO) is adjusted using the external voltage divider network of RENT and RENB. The EN/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 equations can be used to determine the VIN(ON) and VIN(OFF) levels.
VIN(ON) = 6 V (user choice)
RENB = 5 kΩ (user choice)
RENT = [(VIN(ON) / (VEN/UVLO_H) – 1] × RENB
RENB = [(6 V / 1.2 V) – 1] × 5 kΩ = 20 kΩ. Choose standard 20 kΩ.
Therefore VIN(OFF) = 6 V × [1 – (0.09 V / 1.2 V)] = 5.55 V