Supertex, Inc. today introduced the HV9805, an LED driver IC, where the LED light source is arranged as a high voltage LED string in order to accommodate certain lamp form factors, while allowing for cost savings through less complicated cooling and optical arrangements. The driver includes a linear post regulator to provide a pure dc current drive, for flicker free light output. The linear post regulator also provides protection from line voltage transients.
HV9805 supports a simple and low cost driver circuit, which combines a PFC boost stage and a linear post regulator for regulating the LED current to a dc value. The boost stage employs the boundary conduction mode, with the output regulated for lowest overhead voltage at the linear regulator. The headroom voltage can be freely selected to optimize the efficiency of the post regulator or to minimize the cost or size of the bus capacitor.
The boost converter employs a cascode switch for high speed switching and convenient generation of the housekeeping (VDD) supply. The low voltage device of the cascode switch is integral to the HV9805 and is rated at a current of 1A. VDD power is derived with high efficiency and without the need for extra components or magnetic windings.
“The HV9805 offers an interesting alternative for lowering the cost of LED lighting solutions, while improving the performance of the light source. High power factor, low THD, and high efficiency are attained through use of two simple stages. The HV9805 offers the lighting designer a powerful alternative for optimizing their designs, as they examine the tradeoffs of performance and lower system cost,” states Alex Mednik, Application Engineering Director at Supertex.
The HV9805 is available in a lead(Pb)-free/RoHS compliant 10-lead MSOP package (HV9805MG-G). Samples are available from stock. Pricing is US$0.77 each in 1K quantities.