STLD40DPUR STMicroelectronics

STLD40D White LED power supply for large display backlight Features Inductor switches boost controller PFM mode control High efficiency over wide range of input voltage from 3.0 V to 5.5 V Over voltage protection with automatic restart QFN8 (3 x 3 mm) Adjustable peak current limit Enable pin with possibility of PWM dimming control Low shutdown current < 1 A resistor R . The device can be turned ON/OFF LED Small external component through the logic enable signal pin EN. By Good load and line regulation applying a low frequency PWM signal the LEDs can be dimmed. The maximum peak inductor QFN8 3 x 3 mm current can be programmed by connected a resistor R to the pin R . SET SET Applications White LED supply for LCD backlight Mobile phone PDA and organizers Any handsets powered form 3.0 V to 5.5 V Description STLD40D is a boost converter that operates from 3.0 V to 5.5 V. It can provide an output voltage as high as 37 V and can drive up to 10 white LEDs in series. The converter is a PFM (pulse frequency modulation) inductor switch that can work in discontinuous (DCM) mode operation. A minimum OFF time of the embedded boost switch T is SW fixed internally and allows limiting the switching frequency. The output current capability is 20 mA with an output voltage of 37 V. The regulation is done by sensing the LED current through the Table 1. Device summary Order code Package Packaging STLD40DPUR QFN8 (3 x 3 mm) 3000 parts per reel May 2011 Doc ID 12203 Rev 7 1/16 www.st.com 16Contents STLD40D Contents 1 Block diagram 3 2 Pin configuration 4 3 Maximum ratings 5 4 Electrical characteristics . 6 5 Functional description . 7 5.1 Boost controller . 7 5.2 Adjustable peak inductor current limit 7 5.3 Enable 7 5.4 OVP 7 6 Typical application 8 7 Typical performance characteristics 9 8 Package mechanical data 11 9 Revision history . 15 2/16 Doc ID 12203 Rev 7