Research on the LED driver with programmable flash timer charge pump

Because the mobile and personal electronics designers will be more high-performance camera embedded in a new generation of products, the amount of current requirements for flash with increasing demand to flash chip in a smaller package, and in providing high power output with excellent control function at the same time, can also protect LED. Research Nobel (AnalogicTech) AAT3170 will be a flash timer with a high flash current drive current control of 32 level digital combination, provide a hitherto unknown performance for the next generation of many kinds of product design, so as to achieve the best effect of LED flash, and provide good protection function of flash LED.

AAT3170 is the current output of the charge pump chip a high output and high efficiency, is suitable for the application of white LED flash. It is a 600mA dual regulator output current flash drive and a safety timer combination, in addition, each LED output by Nobel (Advanced Simple AS2Cwire research Serial Control) interface through a GPIO output channel 32 programming control.

AAT3170 flash timer can use an external capacitor programming. The capacitor can be used to protect the LED when the control logic fault occurs, so as to avoid excessive loss, and can be used to preset the duration of the flash duration. In addition, the device has three modes through a load switch mode (1 x), intermittent mode (1.5 x) and double mode (2x) adjustable capacity and an internal sensing circuit combined with output of LED, in order to achieve maximum efficiency. When the lower working current of the LED, at 1 x and 1.5 x, the current consumption of the battery is the lowest, for example in the lighting mode or shooting motion picture light source mode, battery time is longer than in flash mode. The dual current inhaler allows the system designer to choose a single or dual (independent cathode) flash LED configuration.

32 single wire interface AT3170 can eliminate the transition, and in a flash or other light emitting mode, so that the designer can flexibly control the brightness of. The interface can also be programmed to provide an alternative current stable voltage for the system's additional load.

AAT3170 requires only 5 external components: two 1 F ceramic capacitor, used as capacitor charge pump; a 1 CIN F capacitor; a 1 COUT F capacitor; a capacitor for setting additional flash timer duration. The device also comes with a thermal management system and a built-in soft start circuit.