Power Integrations Expands TOPSwitch-HX Family of Offline Switcher ICs

Power Integrations has announced a package for its TOPSwitch-HX family of AC-DC power conversion ICs. The small package combined with high operating frequency of TOPSwitch-HX enables lightweight power supplies from 20 to 100 watts. Applications include adapters for notebook computers, as well as power supplies for LCD monitors and flat-panel TVs, in which slim form factor and high efficiency have become critical design criteria. The "L" shaped lead-bend allows the company's innovative eSIP package to lie flat against the printed circuit board with the heatsink pad facing upwards. The device stands just 2 millimeters above the board giving plenty of space for a heatsink and enabling extremely slender power supply designs.



The elegance of adapter designs enabled by the package is demonstrated by a reference design (DER-196) for a 65 W notebook adapter only slightly larger than a standard deck of playing cards. The design, which complies with the upcoming ENERGY STAR 2.0 specifications for external power supplies, utilizes a TOP261 chip in the new eSIP-L package. The IC combines a 700 V switching power MOSFET with controller and supervisory functions into a single monolithic IC, reducing the need for bulky heatsinks required in designs using traditional TO-220 packaged MOSFETs and discrete controllers, and eliminating the need to encase the electronics with thermally-conductive potting compound. The package's 90-degree pin deflection enables the PCB, chip and heatsink to lie parallel to each other, while the high switching frequency of TOPSwitch-HX eliminates the need for an expensive planar type transformer. This, together with Power Integrations' proprietary transformer design, greatly reduces both the cost and size of the notebook adapter. The TOP260LN, TOP261LN and TOP262LN devices suitable for slim adapters from 20 W to 100 W power levels are available in the new eSIP-L package style immediately from $1.00/ea in 10K unit quantities.