SLVSAH5E December 2010 – May 2019 TPS57114-Q1
The VIN pin voltage falling below 2.6 V disables the TPS57114-Q1 device. If an application requires a higher undervoltage lockout (UVLO), use the EN pin as shown in Figure 22 to adjust the input voltage UVLO by connecting two external resistors. TI recommends using the EN resistors to set the UVLO falling threshold (V(STOP)) above 2.6 V. Set the rising threshold (V(START)) to provide enough hysteresis to allow for any input supply variations. The EN pin has an internal pullup current source that provides the default condition of the TPS57114-Q1 operation when the EN pin floats. Once the EN pin voltage exceeds 1.25 V, the circuitry adds an additional 1.6 µA of hysteresis. Pulling the EN pin below 1.18 V removes the 1.6 µA. This additional current facilitates input voltage hysteresis.
where I(hys) = 1.6 µA, I(1) = 1.6 µA, V(ENRISING) = 1.25 V, V(ENFALLING) = 1.18 V.