SNVSB29C October 2018 – June 2021 LM5143-Q1
The LM5143-Q1 operational input voltage range is from 3.5 V to 65 V. The device is intended for step-down conversions from 12-V, 24-V, and 48-Vautomotive supply rails. The application circuit in Figure 8-1 shows all the necessary components to implement an LM5143-Q1 based wide-VIN dual-output step-down regulator using a single supply. The LM5143-Q1 uses an internal LDO subregulator to provide a 5-V VCC bias rail for the gate drive and control circuits (assuming the input voltage is higher than 5 V plus the necessary subregulator dropout specification).
In high input voltage applications, make sure the VIN and SW pins do not exceed their absolute maximum voltage rating of 70 V during line or load transient events. Voltage excursions that exceed the Absolute Maximum Ratings can damage the IC. Proceed carefully during PCB board layout and use high-quality input bypass capacitors to minimize voltage overshoot and ringing.