HV9982
Three-Channel, Closed-Loop, Switch Mode LED Driver IC
Features
►
Switch mode controller for single-switch converters
►
Closed loop control of output current
♦
Buck
♦
Boost
♦
SEPIC
►
High PWM dimming ratio
►
Internal 40V linear regulator
►
Constant frequency operation
►
Programmable slope compensation
►
Linear and PWM dimming
►
+0.2A/-0.4A gate drives for the switching FETs
►
Output short circuit protection
►
Output over voltage protection
►
Hiccup mode protection
►
Analog control of PWM dimming
General Description
The HV9982 is a three-channel, closed loop, peak current
mode PWM controller for driving a constant output current.
It can be used for driving either RGB LEDs or multiple
channels of white LEDs.
The HV9982 includes a 40V linear regulator which provides
an 8.0V supply to power the IC. The switching frequencies
of the three converters are controlled by an external clock
signal. The channels operate at a switching frequency of
1/12
th
of the external clock frequency to minimize 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 help to disconnect the input in case of an
output short circuit condition. HV9982 includes a hiccup
mode protection for both open LED and short circuit
condition with automatic recovery when the fault clears.
Applications
►
RGB backlight applications
►
Multiple string white LED driver applications
Typical Boost Application Circuit
VIN
VDD
VDD1
VDD2
GATE1
CS1
GND1
OVP1
FLT1
VDD3
FDBK1
PWMD1
PWMD2
PWMD3
REF1
REF2
REF3
EN
CLK
GND
COMP1
COMP2
COMP3
SKIP
S1
S2
GATE3
CS3
GND3
OVP3
FLT3
FDBK3
RAMP
GATE2
CS2
HV9982
GND2
OVP2
FLT2
FDBK2
SUPERTEX [ Supertex, Inc ]
