LED7707TR;LED7707;STEVAL-ILL021V1;EVALED7707;中文规格书,Datasheet资料.pdf

April 2009 Rev 3 1/47 47 LED7707 6-rows 85 mA LEDs driver with boost regulator for LCD panels backlight Features ■ Boost section – 4.5 V to 36 V input voltage range – Internal power MOSFET – Internal +5 V LDO for device supply – Up to 36 V output voltage – Constant frequency peak current-mode control – 250 kHz to 1 MHz adjustable switching frequency – External synchronization for multi-device application – Pulse-skip power saving mode at light load – Programmable soft-start – Programmable OVP protection – Stable with ceramic output capacitors – Thermal shutdown ■ Backlight driver section – Six rows with 85 mA maximum current capability (adjustable) – Rows disable option – Less than 10 μs minimum dimming on-time – ±2 % current matching between rows – LED failure (open and short-circuit) detection Applications ■ LCD monitors and TV panels ■ PDAs panel backlight ■ GPS panel backlight Description The LED7707 consists of a high efficiency monolithic boost converter and six controlled current generators (rows) specifically designed to supply LEDs arrays used in the backlighting of LCD panels. The device can manage an output voltage up to 36 V (i.e. 10 white LEDs per row). The generators can be externally programmed to sink up to 85 mA and can be dimmed via a PWM signal (1 % dimming duty-cycle at 1 kHz can be managed). The device allows to detect and manage the open and shorted LED faults and to let unused rows floating. Basic protections (output over-voltage, internal MOSFET over-current and thermal shutdown) are provided. VFQFPN-24 4x4 Table 1. Device summary Order codes Package Packaging LED7707 VFQFPN-24 4x4 (exposed pad) Tube LED7707TR Tape and reel / Contents LED7707 2/47 Contents 1 Typical application circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 2 Pin settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2.1 Connections . . . . . . . . . . . . . .