HV9921/HV9922/HV9923 3-Pin Switch-Mode LED Lamp Driver ICs Features Description HV9921/HV9922/HV9923 are pulse-width modulated Constant output current: (PWM), high-efficiency, LED driver control ICs. They - HV9921 20mA allow efficient operation of LED strings from voltage - HV9922 50mA sources ranging up to 400VDC. HV9921/22/23 include - HV9923 30mA an internal high voltage switching MOSFET controlled Universal 85 - 264VAC operation with fixed off-time (T ) of approximately 10 s. The OFF LED string is driven at constant current, thus providing Fixed off-time buck converter constant light output and enhanced reliability. The out- Internal 475V power MOSFET put current is internally fixed at 20mA for HV9921, 50mA for HV992, and 30mA for HV9923. The peak cur- Applications rent control scheme provides good regulation of the output current throughout the universal AC line voltage Decorative lighting range of 85 to 264VAC or DC input voltage of 20 to Low power lighting fixtures 400V. 2014 Microchip Technology Inc. DS20005311A-page 1HV9921/HV9922/HV9923 TO OUR VALUED CUSTOMERS It is our intention to provide our valued customers with the best documentation possible to ensure successful use of your Microchip products. To this end, we will continue to improve our publications to better suit your needs. Our publications will be refined and enhanced as new volumes and updates are introduced. If you have any questions or comments regarding this publication, please contact the Marketing Communications Department via E-mail at docerrors microchip.com. We welcome your feedback. Most Current Data Sheet To obtain the most up-to-date version of this data sheet, please register at our Worldwide Web site at: