General
Description
The AS6541 device is an integrated, adjustable, constant-current LED driver that can drive loads up to 1200mA. The output current level can be adjusted through an external resistor. The device is designed to supply a low voltage high-power flash LEDs ideal for camera
flash applications.
Two simple logic control inputs (EN and FLASH)enable and disable flash and movie mode operation ofthe AS6541. Movie-mode and Flash-mode currentlevels are independently fixed by an external resistors
(RSET).
For Flash mode, a default timer can be used eitherto terminate a flash event or as a safety flash timer. In both mode (flash and movie mode), the flash LED current can be programmedin 16 steps by the 1-wire dimming interface at EN pin. The AS6541 has an internal deglitch circuit, it can avoid EN/Flash’s false triggering caused by the interference of the external circuit. Powered by a single Li_Ion battery
cell or three to four NiCd, NiMH, or Alkaline battery cells, the AS6541 used low voltage LED, which reduce the system cost
and improve the EMI performance.
Protection circuits prevent
damage to the device in case of overload, over-temperature and short circuit protection. The supply voltage ranges from 2.7V to 5.5V and is ideally suited for all applications powered by
a single Li_Ion battery. The AS6541 also features a very low shutdown current (less than 1uA), an automatic soft-start mode to limit inrush current, as well as over current and over temperature shutdown control.
The AS6541 is offered in Green 10-pin DFN3030 package and is specified over an ambient temperature range
of -40˚C
to 85˚C.
Features
● Output Current Up to 1200mA
● Adjustable FLASH Mode Current
● Minimum External Components: No Inductors● Wide VIN Range: 2.7V to 5.5V
● 0.8 Second Timeout in Flash Mode
● Less than 1uA Shutdown Current
● 1-wire Control Movie/Torch Mode
● 16 Steps Dimming
● Automatic Soft Start Limits Inrush Current
● Under Voltage Lock-Out
● Short Circuit Protection
● Output Over Load Protection (RSET<20K)
● Over Temperature Protection
● Thermal management and Current Scale Back
● Separate Hardware Flash and Movie Enable
● Without EMI and Switch Noise
● RoHS and Green Compliant
● 10- pin, 3mm X 3mm DFN Packages
● -40℃ to +85 ℃ Temperature Range
Applications
● Camera Flashes and Movies
● Cell Phones or Smart Phones
● PDAs and Digital Camera
● White LED Biasing
● Mobil Handsets
● Tablet PCs and Laptops/Netbooks
● Camcorder Video Light (Movie Light)
