300W Isolated DC-DC Converter

This reference design provides specification, block diagram and PCB layout data of 300W isolated DC-DC converter which is small size and suitable for consumer applications.

Block diagram of 300W Isolated DC-DC converter.
Block Diagram
Efficiency curves of 300W Isolated DC-DC converter.
Efficiency Curves


  • Input voltage : DC 36 to 75V
  • Output voltage : DC 12V
  • Output power : 300W
  • Circuit topology : Phase Shift Full Bridge + Synchronous Rectification


Features of 300W Isolated DC-DC converter.
  • Total efficiency : 94.5%(Vin=48V, 100% load)
  • Outline size : 82mm x 82mm  x 24mm
  • Provides appropriate power MOSFETs and photocouplers totally.

Reference design files

Design, Document

“Design・Document” contains the documents listed below.

Name Date

Design, File

“Design・File” contains the documents listed below.

*1:Actual PCB was designed on CR5000BD.
   The other files were made from CR5000BD file.
*2:The data was generated on CR5000BD.

Toshiba items

Part Number Device Category Portion Usage Description
TPN1200APL MOSFET Primary side・4 U-MOSIX-H/100V/10mΩ(max)@VGS=10V/TSON Advance
TPH3R70APL MOSFET Secondary side synchronous rectification・4 U-MOSIX-H/100V/3.7mΩ(max)@VGS=10V/SOP Advance
TLP291(SE GR Photocoupler Output voltage feedback・1 DC input/Trasistor output/BVS=5000Vrms/11-3C1
TLP2370 Photocoupler Communication between primary side and secondary side・2 DC input/IC output/BVS=3750Vrms/SO6/For high-speed communication
CRS10I30B Schottky Barrier Diode Secondary side・1 30V/1A/VFM=0.42V(max)@IFM=1A/S-FLAT
CTS05F40 Schottky Barrier Diode Secondary side・7 40V/0.5A/VF=0.81V(max)@IF=500mA/SOD-882


Name Date



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