LED Driver. AT9919 Datasheet

AT9919 Datasheet PDF, Equivalent


Part Number

AT9919

Description

High Brightness LED Driver

Manufacture

Supertex

Total Page 7 Pages
PDF Download
Download AT9919 Datasheet PDF


AT9919 Datasheet
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
CIN
RSENSE
L
0 - 2.0V
Doc.# DSFP-AT9919
A061212
CS VIN
RAMP
VDD
ADIM
GATE
DIM GND
AT9919
Supertex inc.
www.supertex.com

AT9919 Datasheet
AT9919
Ordering Information
Part Number
Package
AT9919K7-G
8-Lead DFN
-G indicates package is RoHS compliant (‘Green’)
Packing
3000/Reel
Pin Description
CS 1
VIN 2
RAMP 3
GND
8 GATE
7 GND
6 VDD
ADIM 4
5 DIM
Absolute Maximum Ratings
Parameter
VIN, CS to GND
Value
-0.3 to +45V
8-Lead DFN (K7)
(top view)
Product Marking
VDD, GATE, RAMP, DIM, ADIM to GND
CS to VIN
Continuous power dissipation, (TA = +25°C)
Operating temperature range
Junction temperature
-0.3 to +6.0V
-1.0 to +0.3V
1.6W
-40°C to +125°C
+150°C
9919
YWLL
Y = Last Digit of Year Sealed
W = Code for Week Sealed
L = Lot Number
= “Green” Packaging
8-Lead DFN (K7)
Storage temperature range
-65°C to +150°C
Stresses beyond those listed under “Absolute Maximum Ratings” may cause
permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in
the operational sections of the specifications is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect device reliability.
Typical Thermal Resistance
Package
θja
8-Lead DFN
37OC/W
Mounted on FR-4 board, 25mm x 25mm x 1.57mm
Electrical Characteristics
(VIN = 12V, VDIM = VDD, VRAMP = GND, CVDD = 1.0µF, RCS = 0.5Ω, TA = TJ = -40OC to +125OC* unless otherwise noted)
Sym Description
Min Typ
Max Units Conditions
VIN Input DC supply voltage range
4.5 - 40 V DC input voltage
VDD Internally regulated voltage
4.5 - 5.5 V VIN = 6.0 to 40V
IIN Supply current
- - 1.5 mA GATE open
IIN, SDN
Shutdown supply current
- - 900 µA DIM < 0.7V
IIN, LIM
Current limit
- 30 - mA VIN = 4.5V, VDD = 0V
- 8.0 -
VIN = 4.5V, VDD = 4.0V
fOSC Oscillator frequency
- - 2.0 MHz ---
UVLO VDD Undervoltage lockout threshold
-
- 4.5 V VDD rising
ΔUVLO VDD Undervoltage lockout hysteresis
-
500 - mV VDD falling
* Guaranteed by design and characterization, 100% tested at TA = 25OC. Typical characteristics are given at TA = 25OC.
Doc.# DSFP-AT9919
A061212
Supertex inc.
2 www.supertex.com


Features Datasheet pdf Supertex inc. AT9919 Hysteretic, Buck, High Brightness LED Driver with High-S ide Current Sensing Features ►► Hy steretic control with high-side current sensing ►► Wide input voltage rang e: 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 fo r PWM dimming ►► Over-temperature p rotection ►► -40ºC to +125ºC oper ating temperature range ►► AEC-Q100 compliant Applications ►► Automoti ve LED lighting applications General D escription The AT9919 is a PWM controll er IC designed to drive high brightness LEDs using a buck topology. It operate s 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 opera ting frequency range can be set by sele cting the proper inductor. Operation at high switching frequency is possible since the hysteretic control maintains accuracy even at high frequencies.
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