AT9919 Datasheet, PDF (1/7 Pages) Supertex, Inc – Hysteretic, Buck, High Brightness LED Driver with High-Side Current Sensing

Supertex inc.
AT9919
Hysteretic, Buck, High Brightness LED Driver
with High-Side Current Sensing
Features
►► Hysteretic control with high-side current sensing
►► Wide input voltage range: 4.5 to 40V
►► >90% Efficiency
►► Typical ±5% LED current accuracy
►► Up to 2.0MHz switching frequency
►► Adjustable constant LED current
►► Analog or PWM control signal for PWM dimming
►► Over-temperature protection
►► -40ºC to +125ºC operating temperature range
►► AEC-Q100 compliant
Applications
►► Automotive LED lighting applications
General Description
The AT9919 is a PWM controller IC designed to drive high
brightness LEDs using a buck topology. It operates from an
input voltage of 4.5 to 40VDC and employs hysteretic control
with a high-side current sense resistor to set the constant
output current.
The operating frequency range can be set by selecting the
proper inductor. Operation at high switching frequency is
possible since the hysteretic control maintains accuracy even
at high frequencies. This permits the use of small inductors
and capacitors minimizing space and cost in the overall
system.
LED brightness control is achieved with PWM dimming from
an analog or PWM input signal. Unique PWM circuitry allows
true constant color with a high dimming range. The dimming
frequency is programmed using a single external capacitor.
The AT9919 comes in a small, 8-Lead DFN package and is
qualified for automotive LED lighting applications.
Typical Application Circuit
R_SENSE
L
C_IN
0 - 2.0V
Doc.# DSFP-AT9919
A061212
CS
VIN
RAMP
VDD
ADIM
GATE
DIM
GND
AT9919
Supertex inc.
www.supertex.com