Description
The STLED25 is a fixed frequency, high efficiency, boost DC-DC converter with five parallel high side current sources. It is capable of providing 125 mA of total current with a maximum voltage of 7.5 V on each channel. Each current source supports single or dual LED connection. The output voltage of the step-up converter is automatically set at 100 mV above the highest voltage required on any driver, to guarantee proper operation of the linear current sources. The device implements a self-test feature to detect failure of any of the LEDs and to disable the related channel. The failure status is reset as soon the IC is disabled. This mode of failure detection allows the device to continue operating driver channels that are functioning normally, while avoiding excessive power consumption or associated thermal issues. The control technique is able to maintain the efficiency close to 87% at medium load and higher than 85% at light or full load. The device also includes soft-start control, inrush current limit, thermal shutdown and inductor peak current limit. The STLED25 is packaged in a 12-bump CSP (1.4 x 1.8 mm, 0.5 mm height). Flip-Chip 12 bumps (1.4 x 1.8 mm.)

Features
■ Operating input voltage range from 2.3 V to 5.5 V
■ ± 7.5% LED current accuracy
■ Two LEDs in series per channel
■ High side current source
■ Up to 125 mA of total LED current
■ 86% efficiency at 100 mA
■ PWM dimming with automatic shutdown time window
■ 2.5 MHz switching frequency
■ CSP 12 bumps 0.4 mm. pitch 1.4 x 1.8 mm.

Applications
■ LCD backlight with up to 10 LEDs
■ Cellular phones
■ PDAs