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Step-up DC/DC Converter —Backlight Driver
LN2117
■ General Description
The LN2117 Series is a fixed frequency, constant current step-up DC/DC converter ideal for driving LEDs used in backlighting applications on cellular phones, PDAs and digital cameras etc. Output voltage of up to 20V can be derived, and from a 3.2V input four white Led’s cab be driven in series or alternatively, using a 3.0V input, a network of six LEDs may be driven. Luminance of the LED’s is controlled by changing the duty cycle of a PWM signal applied to the CE pin.
■ Features
Input voltage range
2.5V—6V
Output voltage range
up to 20V
Oscillation frequency
1MHz±20%
Efficiency
88%(When driving 3 white
LEDs in series VIN=3.6V ILED=20mA)
Control
PWM control
Stand-by Current
ISTB=1.
LN2117 Datasheet
