SD42351NA Datasheet, PDF (3/4 Pages) Silan Microelectronics Joint-stock – 350MA WHITE SINGLE LED DRIVER

PIN CONFIGURATION
SD42351
PIN DESCRIPTION
Pin No.
1
2
3
Pin Name
VOUT
GND
VDD
I/O
Pin Description
O
LED Current Output.
--
Ground .
I
Power Supply.
FUNCTION DESCRIPTION
The SD42351 is a low dropout current regulator rated for constant LED sink current. The low quiescent current
and low dropout voltage is achieved by advanced Bi-CMOS process. Its main function is to stabilize the current
passing, other than the LED voltage. Traditional LED drivers are Voltage regulator IC, which will affect the
brightness because of different forward voltages, although the LEDs are in the same structure. SD42351 controls
the brightness of the LED by controlling the current passing by the LED, which eliminates the limitation of
traditional voltage regulator IC.
The device consists of Voltage Reference, Error Amplifier, Power NMOS, Current Sense Resistance, LOGIC
Enable and Over Temperature Protection Circuit. The resistance senses the output current and transform to the
voltage, which compared with the reference voltage. The error is amplified, controls the Power NMOS, so that the
output current is regulated.
Inrush current (over 1 A) in traditional LED drivers is eliminated by the initial current limit circuit, thus constant
sink current in the LED is maintained.
TYPICAL APPLICATION CIRCUIT
Note:The circuit and parameters are reference only, please set the parameters of the real application circuit
based on the real test .
HANGZHOU SILAN MICROELECTRONICS CO.,LTD
Http: //www.silan.com.cn
REV:1.5
2008.03.13
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