AT9933 Datasheet, PDF (1/9 Pages) Supertex, Inc – Hysteretic Boost-Buck (cuk) LED Driver IC

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 8 to 100V 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)
C₁
L₁
L₂
-
VDC
R_CS1
R_D
C_D
Q₁
D₁
D₃
VO
+
R_S1
R_CS2
R_S2
R_REF1
C₂
VIN
VDD
GATE
PWMD
CS1
CS2
GND
REF
AT9933
R_REF2
C₃