HV9910B Datasheet, PDF (1/8 Pages) Supertex, Inc – Universal High Brightness LED Driver

HV9910B
Universal High Brightness LED Driver
Features
General Description
► Switch mode controller for single switch LED drivers
► Enhanced drop-in replacement to the HV9910
► Open loop peak current controller
► Internal 8.0V to 450V linear regulator
► Constant frequency or constant off-time operation
► Linear and PWM dimming capability
► Requires few external components for operation
Applications
► DC/DC or AC/DC LED driver applications
► RGB backlighting LED driver
► Back lighting of flat panel displays
► General purpose constant current source
► Signage and decorative LED lighting
► Chargers
The HV9910B is an open loop current mode control LED driver
IC. The HV9910B can be programmed to operate in either a
constant frequency or constant off-time mode. It includes an
8 – 450V linear regulator which allows it to work from a wide
range of input voltages without the need for an external low
voltage supply. The HV9910B includes a 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 kilohertz. It also includes
a 0 – 250mV linear dimming input which can be used for linear
dimming of the LED current.
The HV9910B is ideally suited for buck LED drivers. Since
the HV9910B operates in open loop current mode control, the
controller achieves good output current regulation without the
need for any loop compensation. PWM dimming response is
limited only by the rate of rise and fall of the inductor current,
enabling very fast rise and fall times. The HV9910B requires
only three external components (apart from the power stage) to
produce a controlled LED current making it an ideal solution for
low cost LED drivers.
Typical Application Circuit
C_IN
C_DD
VIN
VDD
HV9910B
LD
GATE
PWMD
CS
RT GND
R_T
D1
C_O
L1
Q1
R_CS