The TPS40304A is a cost-optimized synchronous step-down controller that operates from 3-V to 20-V inputs. The controller realizes the voltage mode control structure, has the input voltage feedforward compensation, can immediately respond to the input voltage change. The switching frequency is fixed at 600 KHZ. The frequency spread spectrum feature increases jitter in the switching frequency, significantly reducing peak EMI noise and making it easier to comply with EMI standards.
The TPS40304A offers a variety of user-programmable features, including soft start, overcurrent protection (OCP) levels, and loop compensation. The OCP level is programmed by an external resistor connected from the LDRV pin to the circuit ground. During the initial power-up, the TPS40304A enters a calibration cycle to measure the voltage of the LDRV pin and set the internal OCP voltage level.
During operation, the programmed OCP voltage level is compared with the voltage drop when the low side FET is on to determine if there is an overcurrent situation. TPS40304A enters shutdown and restart loop until troubleshooting.
TPS40304A Schematic diagram of simplified application
TPS40304A Device information
TPS40304A Block diagram
