HV9989 Datasheet, PDF (1/22 Pages) Microchip Technology – Three-Channel CCM/DCM Boost LED Driver with Sub-Microsecond PWM Dimming

HV9989
Three-Channel CCM/DCM Boost LED Driver
with Sub-Microsecond PWM Dimming
Features
• Three out-of-phase constant-current boost
converters
• Current loop closed, with sub-microsecond PWM-
dimming pulses, supports PWM dimming >20 kHz
• Internal 40V linear regulator
• External clock input
• External individual reference inputs
• Individual PWM dimming inputs
• Programmable slope compensation
• +0.2A/-0.4A gate drivers
• Independent short circuit protection with hiccup
for each channel
• Latching output open-circuit protection
Applications
• LCD panel back-lighting
Description
HV9989 is a three-channel peak current mode PWM
controller designed to drive single switch converters in
a constant-output current mode. It can be used for driv-
ing either RGB LEDs or multiple channels of white
LEDs.
HV9989 features a proprietary PWM-dimming control
algorithm that achieves a dimming pulse of a few hun-
dred nanoseconds from a Continuous-Conduction
Mode (CCM) or Discontinuous-Conduction Mode
(DCM) boost converter, while maintaining the instanta-
neous LED constant current determined by the external
reference voltage input. This feature permits a dimming
frequency outside of the audible range, and can also
yield a wide dimming ratio in excess of 10,000:1 at low
dimming frequency. Each of the three channels fea-
tures individual PWM-dimming and reference voltage
inputs.
The switching frequencies of the three converters are
controlled by an external clock signal, such that the
channels operate at a switching frequency of 1/12th the
external clock frequency, and are positioned 120° out-
of-phase to reduce the input current ripple.
HV9989 provides a full protection feature set, including
output-short and open-circuit protection, for each indi-
vidual channel that is independent from the other chan-
nels.
HV9989 is powered by a built-in 40V linear regulator.
 2014 Microchip Technology Inc.
DS20005296B-page 1