ͨ¹ýNCP5608 LEDÇý¶¯Æ÷ʵÏÖ¶îÍ⹦ÄÜ

¡¡¡¡Abstract£º With more than 500 mA output current capability£¬ the NCP5608 is capable to drive the high power LED used in the portable photo flash system. Although the embedded I2C makes programming the chip very easy£¬ it turns out that the flash can be trigged by the camera with no access to the I2C protocol. In this case£¬ an extra function is necessary to support this specific pulse mode. This Application Note depicts a simple way to implement such a need without sacrificing extra GPIO at MCU level.

¡¡¡¡The current of each block can be set up independently by means of the I2C protocol£¬ the maximum current being accurately preset by an external resistor. On the other hand£¬ using such an external reference yields a very tight matching between the LED of a given block£º typical 0.2% matching is achieved without the need for extra adjustment. The Charge Pump converter is capable to supply the total current continuously£¬ assuming the PCB is designed to evacuate the heat coming from the operation. Generally speaking£¬ the two blocks are used for their respective function£¬ but one can connect all the LED pins to a single power full LED to generate a 500 mA flash pulse. It is possible also to combine the LED to get the most appropriate function in a given application£º sharing the Flash and the Torch becomes very easy to implement.