This research have developed Forward DC-DC converter to make the high-effective, miniaturized, and high density on-board DC/DC Converter, which selected the synchro-nous rectification circuit to have voltage and current with Active clamp system resonant and also to reduce the loss.

At present, the worldwide competitive telematique equip-ment will apply the high density power supply unit to keep their competitiveness continuously. And the development of home-manufactured DC/DC converter will not only affect to substitute the import equipment to the domestics, but also to become independent on the related techniques.
 
 
1. Design with Multi-layer PCB
2. The design method for magnetic device, applying PCB pattern
  - Miniaturization
  - Thermal resistance
  - The minimization of leakage inductance, thanks to the superior coupling of winding
3. Applying synchronous rectification circuit to increase the effectiveness
4. Able to limit 4~5 times voltage stress by input voltage as applying Active Clamp circuit to resonant circuit
 
 
1. Applying the soft switching method to reduce the switching loss at the maximum, as resonant voltage and current, switching zero-voltage and zero-current during switching
2. The developed converter is for 50[W] with power density of 50[W/in3] and Rated voltage is input voltage of 48[V], output voltage of 5[V], output current of 10[A]
3. The effectiveness of 88% at Zero-voltage switching mode and non zero-voltage switching mode, 90.3% at Non zero-voltage switching mode
 
 
Rated input voltage 48(VDC)
Input voltage range 40 ~ 60 (VDC)
Rated output voltage 5(VDC)
Rated output current 10(ADC)
Switching frequency 250kHz
Power 50(W)
Effectiveness 90(%)
Power density 50(W/in3)
Table 1. Design specific for converter
 
 
The loss by switching and transformers must be continuously reduced through the improvement. Under the result from this research, the developed high density DC/DC converter will contribute high density-stable power supply, high performance special power unit and also all kinds of industrial equipment to develop.

※ This research was jointly conducted with the applied electronic circuit laboratory and Samwha Electronics.