The TPS4030x is a family of cost-optimized synchronous buck controllers that operate from 3-V to 20-V input. The controller implements a voltage-mode control architecture with input-voltage feed-forward compensation that responds instantly to input voltage change. The switching frequency is fixed at 300 KHz, 600 KHz or 1.2 MHz. Frequency Spread Spectrum feature adds dither to the switching frequency, significantly reducing the peak EMI noise and making it much easier to comply with EMI standards. The TPS4030x offers design with a variety of user programmable functions, including soft-start, Over- Current Protection (OCP) levels, and loop compensation. OCP level may be programmed by a single external resistor connected from LDRV pin to circuit ground. During initial power on, the TPS4030x enters a calibration cycle, measures the voltage at the LDRV pin, and sets an internal OCP voltage level. During operation, the programmed OCP voltage level is compared to the voltage drop across the low side FET when it is on to determine whether there is an overcurrent condition. The TPS4030x then enters a shutdown and restart cycle until the fault is removed.