ELM900 Datasheet, PDF (1/2 Pages) List of Unclassifed Manufacturers – WHITE LED FLASHLIGHT DRIVER

ELM900x CMOS White LED flashlight driver
■General description
ELM900x is CMOS white LED flashlight driver. This series can drive two series connected white LED by 1.5V
to 3.0V input voltage. ELM900 series uses an external inductor as voltage booster and consists of an oscillator
circuit and a driving transistor. The input DC power is transformed to constant current pulse when the external
inductor is switched on and repeatly at the frequency : 35kHz, 55kHz.
■Features
• Low noise : 35kHz, 55kHz (constant frequency switching)
• Constant average power control
• High efficiency
• Package : SOT-89
■Application
• White LED flashlight
• Laser pointer
• LCD backlighting
■Maximum absolute ratings
Parameter
Symbol
Limit
Unit
Max.voltage (Vdd to Vss)
Vdd
12
V
Max.voltage (LX to Vss)
Vlx
12
V
Max.current LX
Ilx
200
mA
Power dissipation
Pd
500
mW
Operating temperature
Top
-20 to +70
°C
Storage temperature
Tstg
-55 to +125
°C
■Selection guide
ELM900x-x
Symbol
a
Switching frequency
b
Taping direction
B: Frequency 35kHz
D: Frequency 55kHz
S: Refer to PKG file
N: Refer to PKG file
ELM900 x - x
↑↑
ab
■Pin configuration
SOT-89(TOP VIEW)
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Pin No.
1
2
3
Pin name
VSS
VDD
LX
■Block diagram
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