White LED driver based on inductive boost converter
Integrated 40 V MOSFET with 1.5 A peak current limit
Input voltage range: 6 V to 21 V
Maximum output adjustable up to 36 V
600 kHz to 1 MHz adjustable operating frequency
Typical 39 V fixed overvoltage protection (OVP)
Built-in soft start for boost converter
Drives up to 4 LED current strings
LED current adjustable up to 25 mA for each channel
Headroom control to maximize efficiency
Fixed LED dimming frequency: 8 kHz
LED open fault protection
Brightness control with PWM input
4-channel operation: 90 degree phase shift between
3-channel operation: 120 degree phase shift between
14-lead, 4 mm × 3 mm LFCSP
Notebook PCs, UMPCs, and monitor displays
Four-String, White LED Driver
for LCD Backlight Applications
The ADD5207 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, 1.5 A internal switch and a
pin-adjustable operating frequency between 600 kHz and 1 MHz.
The ADD5207 contains four regulated current sources for
uniform LED brightness. Each current source can drive up to
25 mA and the LED-driving current is pin adjustable by an
external resistor. The ADD5207 drives up to four parallel
strings of multiple series-connected LEDs with a ±1.5% current
matching between strings.
The ADD5207 provides phase shift PWM brightness control
methods. LED dimming control is achieved through the PWM
input. The device includes an 8 kHz LED-dimming oscillator
for driving each current source. The ADD5207 operates over an
input voltage range of 6 V to 21 V, but the device can function
with a voltage as low as 5.6 V.
The ADD5207 also has multiple safety protection features to
prevent damage during fault conditions. If any LED is open, the
device automatically disables the faulty current source. The
internal soft start circuit prevents a high inrush current during
http://www.DataSheet4U.net/ startup. Thermal shutdown protection prevents thermal damage.
The ADD5207 is available in a low profile, thermally enhanced,
4 mm × 3 mm × 0.75 mm, 14-lead, RoHS-compliant lead frame
chip scale package (LFCSP) and is specified over the industrial
temperature range of −25°C to +85°C.
TYPICAL APPLICATION CIRCUIT
14 13 4µF
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datasheet pdf - http://www.DataSheet4U.net/