HV9963設(shè)計的高壓LED驅(qū)動方案
The HV9963 is a current mode control LED driver IC designed to control single switch PWM converters (buck, boost, buck-boost or SEPIC) in a constant frequency mode. The controller uses a peak current-mode control scheme (with programmable slope compensation) and includes an internal transconductance amplifier to accurately control the output current over all line and load conditions. Multiple HV9963s can be synchronized to each other or to an external clock using the SYNC pin. The IC also provides a disconnect switch gate drive output, which can be used to disconnect the LEDs in case of a fault condition using an external disconnect FET. The 10V external FET drivers allow the use of standard level FETs. The low voltage 5.0V AVDD is used to power the internal logic and also acts as a reference voltage to set the current level.
The HV9963 includes an enhanced PWM dimming logic (patent pending) that enables very high PWM dimming ratios. HV9963 also provides a TTL compatible, low-frequency PWM dimming input that can accept an external control signal with a duty ratio of 0-100% and a frequency of up to a few tens of kilohertz.
HV9963主要特性:
Switch mode controller for single switch converters
● Buck
● Boost
● Buck-boost and SEPIC
High output current accuracy
High PWM dimming ratio (>5000:1)
Internal 40V linear regulator
Internal ±2% voltage reference
Constant frequency operation with sync capability
Programmable soft start
10V GATE drivers
Hiccup mode protection for both short circuit and open circuit conditions
HV9963應(yīng)用:
RGB or white LED backlighting
Battery powered LED lamps
Other DC/DC LED drivers
圖1。HV9963功能方框圖
圖2。HV9963典型應(yīng)用電路圖
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