STLDC08PUR STMicroelectronics

STLDC08 Step-up controller for LED supply Features Input voltage range from 0.8 V to 3.6 V Overvoltage protection Drives N-channel MOSFET or NPN bipolar transistor No control loop compensation required FET driver for very precise PWM dimming DFN10 (3 x 3 mm) Applications Single/dual cell NiMH, NiCd, or alkaline batteries Small appliances LED lighting Portable lighting Description The STLDC08 LED driver step-up controller is optimized to operate from one or two NiCd/NiMH or alkaline cells. The IC is able to drive an external MOSFET (N-channel) enabling it for use with wide power levels. Hysteretic control eliminates the need for small signal control loop compensation. The IC integrates an FET driver for a precise PWM dimming. STLDC08 comes in a DFN10 (3 x 3 mm) package. Table 1. Device summary Order code Marking Package STLDC08PUR STLDC08 DFN10 (3 x 3 mm.) February 2011 Doc ID 18476 Rev 1 1/29 www.st.com 29Contents STLDC08 Contents 1 Application diagram . 3 2 Absolute maximum ratings . 5 3 Pin configuration . 6 4 Electrical characteristics . 7 5 Typical performance characteristics 9 6 Block diagram . 11 7 Detailed description 12 7.1 Main control loop . 12 7.2 Start up . 12 7.3 Over voltage protection (OVP) . 13 7.4 Enable/PWM 13 7.5 Dimming 14 8 Application information . 15 8.1 LED current programming 15 8.2 Duty cycle . 15 8.3 Inductor selection . 15 8.4 Inductor peak current limit 17 8.5 Power MOSFET selection 18 8.6 Schottky diode selection 20 8.7 Input capacitor . 20 8.8 Output capacitor 20 9 Demonstration board . 21 10 Layout suggestion . 22 11 Package mechanical data 24 2/29 Doc ID 18476 Rev 1