SNVSBJ0A December 2019 – June 2020 LM5170
Depending on application preference, the failure detection function can be activated or deactivated by the SYNCOUT pin. During start-up, the LM5170 first detects the external resistor attached to the SYNCOUT pin. To enable the failure detection function, do not place resistor between the SYNCOUT and AGND pins (refer to Figure 33 or Figure 34).
To disable the failure detection function, place a 10-kΩ resistor between the SYNCOUT and AGND pins, as shown in Figure 35, and the LM5170 skips the 2- to 3-ms interval of MOSFET failure detection. Instead, it will activate the standby mode in approximately 300 µs after VCC is above 8.5 V and UVLO is greater than 2.5 V. If the circuit breaker is not present or not controlled by the LM5170, do not leave the BRKG and BRKS pins floating, but terminate the BRKG and BRKS pins with 20-kΩ resistors as shown in Figure 35.