AT9932 Datasheet, PDF (1/10 Pages) Supertex, Inc – Automotive Boost-Buck LED Lamp Driver IC

Supertex inc.
AT9932
Automotive Boost-Buck
LED Lamp Driver IC
Features
► Constant output current
► Steps output voltage up or down
► Very low susceptibility to Input voltage transients
► Frequency jitter
► Externally programmable fixed switching frequency
► Temperature foldback with external NTC resistor
► Internal 40V voltage regulator
► +/-1A MOSFET gate driver
► Short LED protection
► Open LED protection
► Input undervoltage protection
► Enable & PWM dimming
► Trimmed reference (±3% accurate)
► AEC-Q100 compliant
Applications
► Automobile lighting
► Battery powered LED lamps
► Other low voltage AC/DC or DC/DC LED drivers
General Description
The AT9932 is an advanced fixed frequency PWM
controller IC designed to control an LED lamp driver using
a boost-buck topology that can step the input voltage up
or down automatically. The IC provides fast output current
transient response and very low susceptibility to input
voltage transients, which allows the lamp driver to pass the
rigorous electrical transient requirements of SAE J1455 or
ISO 7637-2, making the AT9932 an ultimate solution for
automobile lighting. Capacitive isolation protects the LED
Lamp from failure of the switching MOSFET.
The AT9932 features a unique feed-forward current control
scheme, differential output current sensing, soft start,
protection from short or open LED load. Switching frequency
can be programmed with a single external resistor.
The AT9932 includes a temperature fold-back of the output
current using an external NTC resistor. This feature allows
maximizing the light output of the LED load over the entire
operating temperature range.
Typical Application Circuit
C_IN
L₁
R_d
C_{1 Cd}
R_IN
VIN
GATE
M₁
AVDD
R_P
D₁
C_VDD
PVDD
FFP
R_N
PWMD
FFN
R_INC
R₂
UVLO
R_T
RT
SS
C_SS
PGND
R_NTC
GND
NTC
T1
R₁
DIV
REF
FLT
FB
DRP
COMP
T2
JTR
R_REF
R_FLT
R_DRP
C_C
R₃
C_JTR
C_REF
AT9932
L₂
C_O
ZD₁
LED(s)
R_FB
R_OV
R_S
Supertex inc. ● 1235 Bordeaux Drive, Sunnyvale, CA 94089 ● Tel: [phone] ● www.supertex.com