SNVSC75 april 2023 LM5171-Q1
ADVANCE INFORMATION
The DT/SD pin also serves as an emergent latched shutdown pin. During the operation the DT/SD pin is monitored by an internal circuit. The pin is normally regulated at 1.2V with a sourcing current limit of 300uA. Once the pin is externally pulled down below 0.5V for more than 2.5 µs, the LM5171-Q1 shuts down and the state is latched until the UVLO is pulled below 1.25V to unlatch. Figure 7-19shows an example of implementing the emergency latched shutdown function.
When the LM5171-Q1 sets for adaptive dead time scheme, DT/SD pin needs to be pulled up to VDD. In order to implement the emergent latched shutdown control in this case, a 20 kΩ limiting resistor must be placed across the VDD and DT/SD pin, as shown in Figure 7-22.