200mA peak current letter phone photo camera flash circuit, using a AAT3110-4.5 electrical capacitive charge pump chip, the phone lithium battery voltage boost and regulated to
4.5V, to a group of light-emitting diode (LED) provide work for the voltage and 100 ~ 200mA peak current. The peak current through the switch as a flash of VF form a loop. The charge pump input filter capacitor capacitance of lOtiF, output filter capacitor electric capacity 4. 7vF, storage capacitor capacitance of ltiF. Ri, LED light-emitting tube balancing resistor. RP is the peak current regulation section resistance, adjust the resistance of RP can be set peak current size.