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 a change in input voltage. The switching
frequency is fixed at 300 kHz, 600 kHz, or 1.2 MHz.The frequency spread-spectrum (FSS) feature adds 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, overcurrent protection (OCP) levels, and loop compensation.OCP level may be programmed by a single external resistor connected from the 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.
