ZHCS447C SEPTEMBER 2011 – April 2018 TPS84210
PRODUCTION DATA.
The INH pin provides electrical on/off control of the device. Once the INH pin voltage exceeds the threshold voltage, the device starts operation. If the INH pin voltage is pulled below the threshold voltage, the regulator stops switching and enters low quiescent current state.
The INH pin has an internal pull-up current source, allowing the user to float the INH pin for enabling the device. If an application requires controlling the INH pin, use an open drain/collector device, or a suitable logic gate to interface with the pin. Do not place an external pull-up resistor on this pin. Figure 22 shows the typical application of the inhibit function.
Turning Q1 on applies a low voltage to the inhibit control (INH) pin and disables the output of the supply, as shown in Figure 23. If Q1 is turned off, the supply executes a soft-start power-up sequence, as shown in Figure 24. The waveforms were measured with a 2-A constant current load.