The TD7580 is a 240 KHz fixed frequency monolithic step down switch mode regulator with a built in internal Power MOSFET. It achieves 4A continuous output current over a wide input supply range with excellent load and line regulation. The device includes a voltage reference, oscillation circuit, error amplifier, internal PMOS and etc. The PWM control circuit is able to adjust the duty ratio linearly from 0 to 100%. An enable function, an over current protection function and a short circuit prot.