OPERATION OF DC-DC CHARGE PUMP CONVERTER MCP1253 IN BUCK MODE

The algorithm of operation of MCP1253 charge pump converter in buck mode is studied for the first time by detailed measurements of ripples of output voltage and flying capacitor voltage. Some experimental results for MCP1253 operation in regulation buck mode at combinations of input voltage 5.1 V and output voltage 3.5 V, input voltage 5.1 V and output voltage 4.8 V and input voltage 2.2 V and output voltage 1.7 V for the range of load current from 2 to 100 mA are presented as examples. Realized investigations revealed that algorithm of MCP1253 operation in buck mode, described by its manufacturer, is not defined the all different cases of its use. The algorithm depends on the ratio between input and output voltages, their values and load currents.