Clare Introduces Power MOSFETs as Synchronous Rectifiers for Battery Powered Equipment and Solar Chargers
Clare, Inc., a wholly owned subsidiary of IXYS Corp., announced the release of new low voltage Power MOSFETs in small SOIC packages with a breakdown voltage rating of 30V and a gate threshold voltage of 1V. The optimized low gate voltage turn-on specification is well suited for applications in synchronous rectification as well as high frequency switching and power control for battery powered portable equipment. The CPC3801N single MOSFET and the CPC3851N dual MOSFET have a current rating of 1A and 80mΩ of on-resistance.
Targeted applications are low voltage dc-dc converters and synchronous rectification, where MOSFETs can replace rectifier diodes in the output rectification circuit thereby reducing conduction losses. Replacing a diode for rectification (400 to 600mV of forward voltage drop) with these new FETs reduces the voltage drop to 20mV for a 0.25A load, achieving a 20 times reduction of rectification power losses. The ability of these MOSFETs to be switched at high frequencies like 250KHz, enables the use of smaller inductors, transformers and capacitors in dc-dc converters battery chargers and solar chargers circuits.
The CPC3801N and CPC3851N are also well suited for solar chargers as the isolation rectifier between the solar cells and the battery. These MOSFETs have very low gate threshold voltage and are optimized to be driven by the CPC1822/24 photovoltaic solar cells from Clare, turning the FETs on under ambient light conditions allowing the battery to be charged by light. When there is not sufficient light, the MOSFET will turn off and prevent battery discharge.
"These MOSFETs highlight our commitments to energy harvesting applications, where we developed products that enable higher efficiency solar chargers. By coupling the CPC MOSFETs with our solar gate drivers the CPC1822/24, or as we call them our ’solar bulbs’ or ’solar panel chip’, and our SolarBits™ solar cells, we provide the total solution for solar chargers," commented Dr. Nathan Zommer, CEO of IXYS Corp..
