SBVS445A October 2024 – December 2024 TPS7N53
PRODUCTION DATA
The precision enable circuit (EN pin) turns the device on and off. This circuit can be used to set an external undervoltage lockout (UVLO) voltage, as shown in Figure 7-1, to turn on and off the device using a resistor divider between IN, EN, and GND.
This external UVLO solution is used to prevent the device from turning on when the input supply voltage is not high enough and can place the device in dropout operation. This solution also allows simple sequencing of multiple power supplies with a resistor divider from another supply. Another benefit from using a resistor divider to enable or disable the device is that the EN pin is never left floating because this pin does not have an internal pulldown resistor. However, a Zener diode can be needed between the EN pin and ground to comply with the absolute maximum ratings on this pin.
Use Equation 2 and Equation 3 to determine the correct resistor values.
where: