Global Mixed-mode Technology Inc.
G5920/G5921
Ultra Low-Dropout, Constant-Current White LED Bias
Features
Ultra Low 150mV Dropout at 20mA
0.6% High Accuracy Current Matching
20mA Full Scale Current
32 Level Linear Current Brightness Control
PWM Brightness Control
2.5V to 5.5V Supply Voltage Range
SOT-23-6 Package (G5920)
MSOP-8 Package (G5921)
General Description
The G5920/G5921 is a high performance ultra low-
dropout constant current bias supply for white LEDs. It
can be used as an alternative to the simple ballast
resistors in conventional parallel white LEDs applica-
tions. Each white LED bias current is matching to
0.6%.
For dimming control, an enable input pin is controlled
by processor GPIO output pulses for 32 level linear
current. Using a low frequency PWM waveform to this
enable input pin also controls the average LED current
which is proportional to the PWM duty.
The G5920/G5921 is suitable for single cell Li-ion bat-
tery power device that using low forward voltage white
LEDs. The white LEDs can be powered directly from
battery without extra external components. This takes
an advantage of highest efficiency and creates no EMI
problem.
Applications
Mobile Phones
White LED backlighting
Ordering Information
ORDER
NUMBER
G5920TB1U
G5921P8U
Note:TB : SOT23-6
P8: MSOP-8
U: Tape & Reel
ORDER NUMBER
(Pb free)
G5920TB1Uf
G5921P8Uf
MARKING
5920x
5921x
TEMP. RANGE
-40°C to 85°C
-40°C to 85°C
PACKAGE
SOT-23-6
MSOP-8
Pin Configuration
G5920
LED2 1
6 LED1
Typical Application Circuit
Linear Current Dimming
EN
G5920
LED1
LED2
GND 2
5 VCC
LED3
GND
VCC
0.1µF
V
BAT
LED3 3
4 EN
SOT-23-6
G5921
LED2
LED1
VCC
N.C.
1
2
3
4
8
7
6
5
GND
LED4
LED3
EN
PWM Dimming
EN
G5920
LED1
LED2
LED3
GND
VCC
0.1µF
V
BAT
MSOP-8
Ver: 0.4 Preliminary
Feb 03, 2005
TEL: 886-3-5788833
http://www.gmt.com.tw
1
GMT [ GLOBAL MIXED-MODE TECHNOLOGY INC ]
