GM2102 Datasheet, PDF (1/6 Pages) List of Unclassifed Manufacturers – CONSTANT CURRENT DC/DC WHITE LED DRIVER

PRELIMINARY
GM2102
CONSTANT CURRENT DC/DC WHITE LED DRIVER
GENERAL DESCRIPTION
The GM2102 is a member of Gamma Microelectronics’s
family of white LED drivers.
The GM2102 is a fixed frequency step-up DC/DC
converter designed to operate as a constant-current
source. It is ideal for driving light emitting diodes (LEDs)
whose light intensity is proportional to the current
passing through them and not on the voltage across their
terminals as it directly regulates the output current.
The wide input voltage range allows the device to work
from a variety of input sources. A single external
resistor sets LED current between 5mA and 40mA,
which can then be easily adjusted using either a DC
voltage or a PWM signal. In Shutdown mode, the
LED’s are disconnected from the output with the
maximum quiescent current of 1µA for the entire circuit.
FEATURES
• Drives Six White LED’s from 1.8 V
• 1.2Mhz Fixed Frequency Switching
• Minimum operating input voltage 1.2V
• 90% efficiency
• Accurately adjustable LED current
• Current Regulation even when
Vin > Vout
• Disconnects LED’s in Shutdown mode
• Available in SOT23 Package ideal for
space conscious portable applications
TYPICAL APPLICATION
Vin
2.7V to 4.2V
6.8 uH
D1
C1
4.7 uF
PWM
DIMMING
CONTROL
SIGNAL
6
1
Vin
SW
GM2102
5
3
SHDN
LED
Rset
GND
4 Rset
2
1.5K
C2
1 uF
15mA
APPLICATIONS
• Cellular Phones
• Digital Cameras
• Handheld Computers
• Portable Audio players
• Pagers
• Other White LED applications
Revision 1, March 2003
1
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