AT9933_12 Datasheet, PDF (1/9 Pages) Supertex, Inc – Hysteretic Boost-Buck (Ćuk) LED Driver IC

Supertex inc.
AT9933
Hysteretic Boost-Buck (Ćuk)
LED Driver IC
Features
►► Constant current LED Driver
►► Steps input voltage up or down
►► Low EMI
►► Variable frequency operation
►► Internal 75V linear regulator
►► Input and output current sensing
►► Input current limit
►► Enable & PWM dimming
►► Ambient temperature rating up to 125°C
►► Meets AEC-Q100 requirements
Applications
►► Automotive LED Lighting
Reference Documents
►► AEC-Q100 Rev. F, 7/18/2003
►► SAE J1752-3
General Description
The AT9933 is a variable frequency PWM controller IC,
designed to control an LED lamp driver using a low-noise
boost-buck (Ćuk) topology. The AT9933 uses patent-pending
hysteretic current-mode control to regulate both the input and
the output currents. This enables superior input surge immunity
without the necessity for complex loop compensation. Input
current control enables current limiting during startup, input
under-voltage and output overload conditions. The AT9933
provides a low-frequency PWM dimming input that can accept
an external control signal with a duty cycle of 0 - 100% and a
high dimming ratio.
The AT9933 based LED driver is ideal for automotive LED
lamps. The part is rated for up to 125°C ambient temperatures
and is AEC-Q100 compliant.
Typical Application Circuit
D₂ (optional)
L₁
VDC
R_CS1
C₁
R_D
C_D
Q₁
L₂
D₁
-
D₃
VO
+
R_S1
R_REF1
VIN
GATE
CS1
VDD
R_CS2
C₂
PWMD
CS2
R_S2
R_REF2
GND
REF
AT9933
C₃
Doc.# DSFP-AT9933
B061710
Supertex inc.
www.supertex.com