DC/DC Reference Design Ensures 97% Efficiency

irf.com/technical-info/refdesigns/ irdc2086-330w.pdf
Easing development of 48V brick or embedded power supplies, the IRDC2086-330W reference design enlists an IR2086S dc bus converter control IC and DirectFET power MOSFET chipset to deliver efficiencies up to 97%. In addition to ensuring high efficiency, the design reduces the number of components from three ICs and 14 FETs to one chip and eight FETs. The IR2086S full-bridge controller operates at programmable frequencies up to 500 kHz and integrates a softstart capacitor that gradually increases duty cycle to 50% over 2,000 cycles. This limits in-rush current during start-up and maintains equal pulse widths for the high-and low-side MOSFETs throughout the start-up sequence. The reference design also includes an assembled printed circuit board and a CD-ROM containing a user guide, data sheets, PCB files, and application notes. Single-piece pricing $250. For more information, contact Wayne Yoshida at INTERNATIONAL RECTIFIER, El Segundo, CA. (310) 252-7726.

See Associated Figure

Key Components

1. IR2086S primary-side, full-bridge control IC operates at high frequency (programmable to 500 kHz). In addition to features already mentioned, IR's high voltage IC technology used in the IR2086S works with the company's DirectFET MOSFET packaging technology to reduce primary temperature as much as 40°C for increased system reliability

2. Eight power train MOSFETs: four IRF6646 80V DirectFET primary-side MOSFETs and four IRF6635 30V DirectFET secondary-side synchronous MOSFETs

3. IRF7830 80V MOSFET for bias switching

4. Two IRF6621 30V small can DirectFET MOSFETs for the secondary clamp 5IRDC2086-330W fully-assembled printed circuit board

6. CD-ROM as noted; PCB files are available as Gerber, .dxf and .cad

7. IR's on-line design tool, myPOWER, can be used to customize MOSFET selection to suit user applications. The myPOWER on-line design tool is available at no charge, after a simple registration process, at http://mypower.irf.com.