TFS761HG

The TFS761HG is incorporate both a high-power two-switch-forward converter and a mid-power fly back (standby) converter into a single, low-profile eSIP™ power package. The single chip solution provides the controllers for the two-switch-forward and fly back converters, high- and low-side drivers, all three of the high-voltage power MOSFETs, and eliminates the converter’s need for costly external pulse transformers. The device is ideal for high power applications that require both a main power converter (two-switch forward) up to 326 W, and standby converter (fly back) up to 20 W. TFS761HG includes standard set of comprehensive protection features, such as integrated soft-start, fault and over-load protection, and hysteretic thermal shutdown. TFS761HG utilizes advanced power packaging technology that simplifies the complexity of two-switch forward layout, mounting and thermal management, while providing very high power capabilities in a single compact package. The devices operate over a wide input voltage range, and can be used following a power-factor correction stage such as HiperPFS.

Two-switch-forward power converters are often selected for applications demanding cost-effective efficiency, fast transient response, and accurate tolerance to line voltage fluctuation. The two-switch-forward controller incorporated into TFS761HG devices improves on the classic topology by allowing operation considerably above 60% duty cycle. This improvement reduces RMS currents conduction losses, minimizes the size and cost of the bulk capacitor, and minimizes output diode voltage ratings. The advanced design also includes transformer flux reset control (saturation protection) and charge-recovery switching of the high-side MOSFET, which reduces switching losses. This combination of innovations yields an extremely efficient power supply with smaller MOSFETs, fewer passives and discrete components, and a lower-cost transformer.