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.

Features of 300W Isolated DC-DC converter.
Block diagram 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.


Input voltage DC 36 to 75V
Output voltage DC 12V
Output power 300W
Circuit topology Phase Shift Full Bridge + Synchronous Rectification
Efficiency curves of 300W Isolated DC-DC converter.
Efficiency Curves

Design Documents

Materials for designers, such as an overview of circuit operation and explanations of design considerations. Please click on each tab to view the contents.

Design Data

Provides circuit data that can be loaded into EDA tools, PCB layout data, and data used in PCB manufacturing. Available in formats from multiple tool vendors. You can freely edit it with your preferred tool.

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

*2:The data was generated on CR5000BD.

Used Toshiba Items

Part Number Device Category Portion Usage Description
Power MOSFET (N-ch single 60V<VDSS≤150V) Primary side・4 N-ch MOSFET, 100 V, 0.0115 Ω@10V, TSON Advance, U-MOSⅨ-H
Power MOSFET (N-ch single 60V<VDSS≤150V) Secondary side synchronous rectification・4 N-ch MOSFET, 100 V, 0.0037 Ω@10V, SOP Advance, U-MOSⅨ-H
Photocoupler (photo-IC output) Communication between primary side and secondary side・2 Photocoupler (photo-IC output), High-speed, 20 Mbps, 3750 Vrms, 5pin SO6
Schottky barrier diode Secondary side・1 30 V/1 A Schottky Barrier Diode, S-FLAT
Small-signal Schottky barrier diode Secondary side・7 40 V/0.5 A Schottky Barrier Diode, SOD-882(CST2)

Related Documents

We provide materials useful for designing and considering similar circuits, such as application notes for installed products. Please click on each tab to view the contents.


Technical inquiry

Contact us

Contact us

Frequently Asked Questions

A new window will open