JAJSL80A February 2021 – March 2021 TPS541620
PRODUCTION DATA
The precision enable feature of the TPS541620 allows the voltage on the EN1/EN2 pin (VEN) to control the ON/OFF functionality of the device. The EN pin has a 1.4-μA typical internal pullup current source. Floating the EN pin allows the device to start up when a valid input voltage is applied. The TPS541620 switching action and output regulation are enabled when VEN is greater than 1.2 V (typical). While the device is switching, if the EN voltage falls below 1.1 V (typical), the device stops switching.
It is recommended to enable the device at a voltage greater than the minimum input voltage. Control the turn-on and turn-off using a resistor divider on the EN1 (EN2) pin, between VIN and AGND (see Figure 7-1). Set the divider to a voltage greater than the minimum input voltage as shown in Figure 7-2. Select a top enable resistor of 100 kΩ and use Equation 1 for RENB selection. It is recommended to use divider resistors with 1% tolerance or better and with a temperature coefficient of 100 ppm or lower.
The minimum input voltage of the TPS541620 is 4.5 V, however, the minimum input voltage increases at higher output voltages. Figure 7-2 plots the minimum required input voltage for each of the allowable switching frequencies across the output voltage range. It is recommended to control the turn-on and turn-off of the device at an input voltage greater than the minimum shown in Figure 7-2 using a resistor divider on the EN1 (EN2) pin, between VIN and AGND (see Figure 7-1).