High Efficiency, Eight-String, White LED
Driver for LCD Backlight Applications
White LED driver based on inductive boost converter
Integrated 50 V MOSFET with 2.9 A peak current limit
Input voltage range: 6 V to 21 V
Maximum output adjustable up to 45 V
350 kHz to 1 MHz adjustable operating frequency
Built-in soft start for boost converter
Drives up to eight LED current sources
LED current adjustable up to 30 mA for each channel
Headroom control to maximize efficiency
Adjustable output dimming frequency: 200 Hz to 10 kHz
LED open/short fault protection
Selectable brightness control interface modes
SMBus serial interface
Selectable dimming controls
Fixed delay PWM dimming control with 8-bit resolution
No delay PWM dimming control with 8-bit resolution
Phase shift PWM dimming control with 8-bit resolution
Direct PWM dimming control
DC current dimming mode with 8-bit resolution
28-lead, 4 mm × 4 mm LFCSP
Notebook PCs, UMPCs, and monitor displays
The ADD5201 is a white LED driver for backlight applications
based on high efficiency, current mode, step-up converter tech-
nology. It is designed with a 0.15 Ω, 2.9 A internal switch and a
pin adjustable operating frequency between 350 kHz and 1 MHz.
The ADD5201 contains eight regulated current sources for
uniform brightness intensity. Each current source can be
driven up to 30 mA.
The ADD5201 drives up to eight parallel strings of multiple
series connected LEDs with a ±1.5% current regulation accuracy.
The device provides an adjustable LED driving current up to
30 mA for each channel by an external resistor. The ADD5201
provides various brightness control methods. The LED dimming
control can be achieved through SMBus and/or pulse-width
modulation (PWM) input. Each dimming mode is selectable
STEP-UP SWITCHING REGULATOR
EIGHT CURRENT SOURCES
8-BIT DIMMING CONTROL LOGIC
AUTODISABLE FOR LED OPEN/SHORT
with two external dimming mode selection pins. The device pro-
vides a pin adjustable output dimming frequency range from
200 Hz to 10 kHz.
The ADD5201 operates over an input voltage range of 6 V to
21 V, but the device can function with a voltage as low as 5.4 V.
The ADD5201 has multiple safety protection features to prevent
damage during fault conditions. If any LED is open or short, the
device automatically disables the faulty current regulator. The
internal soft start prevents inrush current during startup. A
thermal shutdown protection prevents thermal damage.
The ADD5201 is available in a low profile, thermally enhanced,
4 mm × 4 mm × 0.75 mm, 28-lead, RoHS compliant lead frame
chip scale package (LFCSP) and is specified over the industrial
temperature range of −25°C to +85°C.
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