The TPS40200 is a flexible nonsynchronous controller with a built-in 200-mA driver for P-channel FETs. The circuit operates with inputs up to 52 V, with a power-saving feature that turns off driver current once the external FET has been fully turned on. This feature extends the flexibility of the device, allowing it to operate with an input voltage up to 52 V without dissipating excessive power. The circuit operates with voltage-mode feedback and has feed-forward input-voltage compensation that responds instantly to input voltage change. The integral 700-mV reference is trimmed to 2%, providing the means to accurately control low voltages. The TPS40200 is available in an 8-pin SOIC and supports many of the features of more complex controllers.