Supertex HV9971高精度LED电流控制解决方案

Supertex公司的 HV9971是不连续导通模式（DCM）反激LED驱动器，可以工作满负荷100kHz开关频率，通用80-264VAC输入电压，±3% LED电流精度，自适应于外部元件误差和寄生参数，输出开路和短路保护，主要用在低功耗照明。本文介绍了HV9971主要特性，功能方框图和典型应用电路图。
The HV9971 is a primary-side control IC for driving a discontinuous conduction mode (DCM) flyback LED driver. The IC is optimized for operation at a constant full-load switching frequency of 100kHz and the universal input AC voltage range of 80-264VAC. It maintains 3% variation of the LED current setting, and features tight line and load regulation. The proprietary primary-side output current control employed in the HV9971 makes the output current setting insensitive to most component tolerances and parasitics without use of an opto-feedback.
The HV9971 LED driver is fully protected against output open and short circuit conditions and input under-voltage. It also offers a logic input for dimming the LED light output by means of pulse-width modulation of the output current.
The HV9971 is ideally suited for driving high-brightness LEDs in low-power lighting fixtures such as incandescent bulb retrofits.
HV9971主要特性：
►► Programmable true constant current operation
►► ±3% LED current accuracy
►► Adaptive to external component tolerances and parasitics
►► Primary-side current sensing
►► Output open circuit protection
►► Output short circuit protection
►► Input under voltage lockout
►► PWM dimming / enable
►► Universal 80-264VAC operation
►► Fixed frequency operation
HV9971应用：
►► Low power lighting fixtures

图1。HV9971功能方框图

图2。HV9971典型应用电路图
详情请见：
http://www.supertex.com/pdf/datasheets/HV9971.pdf