The Design Of Power Management Module With Charge Pump

A kind of power management module is designed in this paper, witch is mainlyused in low voltage power supply for 5V. Its main structure is the charge pump circuitand LDO voltage regulator circuit. When the battery capacity is insufficient inelectricity which is below the rated voltage at the output, Charge Pump will beupgraded, the maximum of which is double the original voltage. After pressureresistance, the output voltage is feed back to the error amplifier (AMP) negative input.After this voltage was compared with REF, we can get the magnified error voltage.The error was used to control the charge pump voltage conduction resistance (alsoknown as controlled resistance), then we get a stable output voltage. This circuit hasbeen designed by the simulation analysis, design of various simulation results havebeen achieved the expected goals.This design has several merits:①Electromagnetic compatibility (EMC) is good.②)A small ripple.③LDO Voltage output, low load regulation.④Extending battery life.Charge Pump and LDO integrated design can be realized in two working condition:①when the battery voltage is greater than the rated output voltage, LDO can use aseparate mode. This is good use of a low-voltage of LDO voltage differenceproperties greatly enhance the power conversion efficiency.②when the battery voltage is less than the rated output voltage, through the chargepump and LDO integrated mode, output voltage regulator reached.