LN2118

Step-up DC/DC Converter —Backlight Driver LN2118 ■ General Description The LN2118 Series is a fixed frequency, constant current step-up DC/DC converter ideal for driving LEDs used in backlighting applications on Car GPS screen and digital cameras etc. Output voltage of up to 26V can be derived, and from a 3.6V input four white Led’s cab be driven in series or alternatively, using a 3.6V input, a network of seven parallel legs with three in each may be driven. Luminance of the LED’s is controlled by changing the duty cycle of a PWM signal applied to the CE pin. In addition, an internal MOSFET with an RDS-on of 2Ω is used. Allow profile and small board area solution can be achieved using a chip coil and an ultra small ceramic output capacitor (CL) of 0.22uF. ■ Applications  Car GPS screen ■ Features  Input voltage range  Output voltage range 2.7V—6.0V up to 26V externally set-up reference voltage 0.2V  Oscillation frequency 1.0MHz±20%  Efficienc...