8.1.4 V_DS Fault Condition

The LM5060 includes a V_DS Fault Comparator that senses the voltage difference between the SENSE pin and the OUT pin. If the voltage at the OUT pin falls lower than the voltage at the SENSE pin, the V_DS Fault Comparator will trip and switch the nPGD pin to a high impedance state. It will also initiate charging of the capacitor on the TIMER pin with a 6-µA (typical) current source if V_GS is less than than 5-V, or a 11-µA (typical) current source if V_GS is higher than 5 V. If the voltage on the TIMER pin reaches the typical 2 V fault threshold, the gate of the N-Channel MOSFET is pulled low with a 80 mA (typical) sink current. Figure 23 illustrates a V_DS fault condition during start-up. The nPGD pin never switches low because the V_DS fault comparator detects excessive V_DS voltage throughout the entire sequence.