Rich for boost IC high power LED driver portable charger

Rich technology (RichTek) - RT9269 boost IC low input voltage to 0.8V, stable drive in 1AA 350mA 1W LED battery input, stable driving in 2 AA batteries input 3W LED, accurately set the output current through a feedback resistor, the feedback voltage is 0.25V, in order to reduce their loss.

The IC integrated 500mA MOSFET, switching frequency is 500K, the choice of small size of inductance and capacitance, which can drive 1~4 50mA LED. The no-load current is only 30uA, the turn off current is less than 1uA, and its consumption is very low. Combined with external MOSFET and 2.2uH's small size inductor, the 1W can be driven by either or 3W high power LED, which can be up to 84% efficiency when the battery input is in section AA.

IC for the 1 AA batteries for charging the mobile phone up to 5V, when 0.9V can provide 250mA charging current to the mobile phone, is the best choice for portable battery charger 1AA.

RT9269 input voltage range of 0.8~5.5V, can work reliably in 1AA ~ 3AA battery input, SOT26 small package.

For NOKIA mobile phone charging special requirements - charger no-load voltage above 5.3V, charging down to below 5V, the output end of the cascade of a 0.1~0.22 resistor for current feedback, the charging voltage drops below 5V, the conversion efficiency decreased only about 1%, but it can improve the charging efficiency of 6% above, but also to take into account the most charging on the mobile phone market requirements.