封装：DFN2030-14L

General Description

    The AS6585 is a 3MHz fixedfrequency synchronous boostconverter, optimized for 0.75A/ch, total 1.5A flash current output LED driver with PWM dimming function, for distance dimming camera flash LED application and maximum 800mA movie mode applications using high-current white LEDs in all single cell Li-ion powered products. An adaptive regulationmethod ensures the current for each LED remains inregulation and maximizes efficiency.

    Two simple logic control inputs (ENM and ENF) enable and disable flashand movie mode operation of the AS6585. The movie-modeand flash-mode current levels are independently fixedby two separate resistors (RSETM and RSETF).

For flash mode, a defaulttimer 800mS can be used either to terminate a flash event or asa safety flashtimer. One or two LEDs can beconnected to the AS6585; in the case of two LEDs theoutput current is matched between each diode. The real LED current at flash mode and movie/torch mode can be programmed by external PWM signal at ENM pin.

    The AS6585 integrate an intelligent flash current control mode: during flash current turn-on the input voltage falls below the flash mode VIN Monitor threshold, the flash current is stopped at the level that the current ramp had risen to, at the time of the VIN Flash Monitor events.

    The AS6585 contain a thermal management system toprotect the device; a internal over-voltage protection (OVP) circuitry prevents damaged to the AS6585 from open LED or open circuit conditions; and a cycle-by-cycle current limit prevents damage to the AS6585. Built-in circuitry prevents excessive inrushcurrent during start-up. The shutdown feature reducesquiescent current to less than 1.0μA.

    The 3MHz switching frequency allow for the use of tiny, low profile (0.47uH or 1.0uH) inductors and 4.7uF ceramic capacitors. The device is available in 14-pin 2mmX3mm DFNpackageand is rated over the -40°C to 85°C.