8.3.10.4 Sense-Resistor Open Protection

When the sense resistor is open before the device powers on, the device charges the BOOT capacitor at the power-on moment. The charging current flows through the inductor, the output capacitor, and the RC filter at the FB pin to charge up the FB pin voltage. Once the device detects an FB voltage higher than the 1-V OVP threshold, the device shuts down immediately. For the TPS54200 device, this is a latched shutdown, and the device can be reset by cycling VIN. For the TPS54201 device, once the device shuts down, it starts the overvoltage auto-retry timer t_{HIC_OV}. During the shutdown period, both FETs are kept off. Once the overvoltage auto-retry timer expires, the TPS54201 device restarts again. If the failure still exists, the TPS54201 device repeats the foregoing auto-retry shutdown-and-restart process.