20W Automotive Start-Stop Power Supply Reference Design

February 13, 2020 by Paul Shepard

The TND6323/D automotive start-stop power supply reference design from ON Semiconductor describes the operation and performance for a typical pre−boost application needed in various automotive applications like ADAS, gateway and infotainment. This dc-dc converter ensures proper supply of all subsequent regulators and therefore uninterrupted operation of the application, even at significant input voltage drops down to 1.5V caused by cold cranking.

The design delivers 20W and demonstrates the NCV887801 controller capabilities and incorporates a NVMFS5C442NL 40V N−channel FET and a NRVB460MFS 60V Schottky diode for the power stage.

It is intended for the power supply designer to adopt the circuit directly into a typical system design, making only minimal component changes based on system requirements.

The design is meant to be a complete solution, but it also provides access to key features of the NCV887801. These include automatic wake up, status pin diagnostic function, low IQ, ±2% output accuracy over temperature range, peak current mode control with integrated slope compensation and cycle−by−cycle current limit protection with hiccup−mode overcurrent protection.

Key Features

  • Complete Automotive Reference Design
  • Non−synchronous Boost Converter with an Input Voltage Range of Nominal 3.0V to 7.0V, Capable to Operate Temporary Down to 1.5V, Withstands Peaks Up to 40V
  • 450kHz Switching Frequency for High Efficiency
  • ON Semiconductor NCV887801 Start−Stop Non−synchronous Boost Controller, NVMFS5C442NL 40V N−channel FET and NRVB460MFS 60V Schottky Diode
  • Optional Bypass Circuit with a NVTFS5116PL −60V P−FET to Minimize Losses while the Converter is Not Switching
  • Small Form Factor PCB with Four Layers