Аннотация:The paper presents investigation results concerning output ripple voltage and flying capacitor voltage in the integrated circuit of the MCP 1253 charge pump DC -to- DC converter operating in buck mode with various combinations of input and output voltage values (5.1 and 3.5 V, 5.1 and 4.8 V, 3.26 and 3.02 V, 2.59 and 2.18 V,2.52 and 1.71 V, 2.17 and 1.71 V) when load currents vary of 5…100 mA. The results obtained allowed us to show for the first time that operation algorithms of the charge pumping system in the MCP 1253 integrated circuit depend on the ratio of input to output voltage and variations in the load current.