The HV9985 is a three-channel peak current mode PWM controller for driving single switch converters in a constant output current mode. It can be used for driving either RGB LEDs or multiple channels of white LEDs. The HV9985 features a 40V linear regulator, which provides a 5.0V supply to power the IC. The switching frequencies of the three converters in the IC are controlled either with an external clock signal (the channels operate at a switching frequency of 1/12th of the external clock frequency) or using the internal oscillator. The three channels are positioned 120° out-of-phase to reduce the input current ripple. Each converter is driven by a peak current mode controller with output current feedback. The three output currents can be individually dimmed using either linear or PWM dimming. The IC also includes three disconnect FET drivers which enable high PWM dimming ratios and also helps to disconnect the input in case of an output short circuit condition. The HV9985 includes hiccup mode protection for both open LED and short circuit condition to prevent the IC from shutting down in the case of intermittent faults.

  Switch mode controller for single-switch converters

  Gate drivers optimized for driving Logic Level FETs

  ♦ 0.25A sourcing

  ♦ 0.5A sinking

  Typical ±2% absolute and string-to-string current accuracy (with ±1% sense resistors)

  High PWM dimming ratio up to 5000:1

  10-40V input range

  Constant frequency operation up to 1.0MHz

  On-chip clock or external clock option

  Programmable slope compensation

  Linear and PWM dimming

  Output short circuit protection

  Output over voltage protection

  Hiccup mode protection