Automotive 40-V to 1-kV input flyback reference design supporting regenerative braking test
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This power supply reference design for automotive auxiliary circuits generates a 15-V, 4-A output from a wide input range of 40 V to 1 kV and up to a 1.2-kV transient. The design fits ideally into an 800-V batterydriven hybrid-electric vehicle (HEV) or electric vehicle(EV) traction inverter system. The 40-V minimum input voltage supports the functional safety test for the regenerative braking from the traction motor. This reference design implements a silicon carbide (SiC) MOSFET with high blocking voltage and low gate charge to reduce switching losses. A non-isolated level shifter enables driving the SiC MOSFET from the Si MOSFET driver embedded in the flyback controller. The board includes two flyback converter variants: primary-side regulation (PSR) and optocoupler feedback to make comparisons and address different needs. The transformer design meets qualifications for Automotive AEC-Q200 Grade 1 with reinforced isolation.

  • 40V to 1kV input, 15-V output flyback auxiliary power supply with output power up to 60W
  • Regulated 15V with active start-up circuit for reduced standby power
  • Extendable to higher voltage and higher power range to utilize high voltage capability of SiC MOSFET
  • Two converter variants with PSR and optocoupler feedback included on board
  • Constant switching frequency type of controller with maximum switching frequency of 1MHz and duty cycle range from 0% to 96%

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TI Devices (2)

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Part Number Name Product Family Sample & Buy Design Kits & Evaluation Modules
TL431-Q1  Automotive adjustable precision shunt regulator (pin layout: KRA)  Voltage references  Sample & Buy Not Available
UCC28C43-Q1  1-A, automotive single ended 1MHz current mode PWM controller with 8.4V/7.6V UVLO 100% duty cycle  Offline & isolated DC/DC controllers & converters  Sample & Buy Not Available

CAD/CAE symbols

Part # Package | Pins CAD File (.bxl) STEP Model (.stp)
TL431-Q1 Download
UCC28C43-Q1 Download Download

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Technical documentation

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Application note (2)
Title Type Size (KB) Date
PDF 787 05 Sep 1999
PDF 189 05 Sep 1999
User guide (1)
Title Type Size (KB) Date
PDF 3569 13 Aug 2019
Design files (6)
Title Type Size (KB) Date
ZIP 1705 30 Jan 2020
PDF 963 30 Jan 2020
ZIP 283 21 Feb 2018
PDF 1570 21 Feb 2018
PDF 395 21 Feb 2018
PDF 77 21 Feb 2018
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Reference Designs (1)

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