SLUA987C October   2019  – February 2023 UCC27531-Q1 , UCC28700-Q1 , UCC28730-Q1 , UCC28740-Q1 , UCC28C40-Q1 , UCC28C41-Q1 , UCC28C42-Q1 , UCC28C43-Q1 , UCC28C44-Q1 , UCC28C45-Q1


  1.   Abstract
  2.   Trademarks
  3. 1Introduction
  4. 2Selecting Devices
  5. 3Start-Up Circuitry
  6. 4Noise Coupling
  7. 5Safety
  8. 6Summary
  9. 7Related Documentation
  10. 8Revision History


The market for automotive powertrain electrification products like the high-voltage (HV) traction inverter grows as consumers and regulating agencies demand fewer emissions. In response, manufacturers of hybrid and electric vehicles (xEV) have doubled the HV battery level. Increasing battery voltage from 400 V to 800 V decreases reliance on the internal combustion engine, decreases charging times, and improves driving range. But, changing battery voltage has implications especially regarding safety critical systems that operate during crash events or malfunction. For example, the redundant power supply, which has become common in traction inverter architectures, operates directly off the HV battery. This application note discusses key considerations for high-voltage to low-voltage (HV-LV) redundant power supply design using TI's automotive flyback controllers.