The Design of the Parallel Switching Power Supply System

This study introduces a parallel switching power supply system which is controlled by C8051F020 MCU. The system consists of DC/DC converter, voltage-controlled constant current source circuit, over-current protection circuit and auxiliary power supply. TPS54331 is used to constitute a highly efficient DC/DC converter, reducing the input DC voltage to supply the voltage-controlled constant current source circuit. The parallel current-sharing of the system is realized by the voltage-controlled constant current source circuit. The output current of the two parallel power supply can be adjusted by changing the control voltage. When the output current exceeds the set value, the system starts over-current protection circuit to cut off the power and delays to restore power automatically after a certain period of time. The test results show that the system is stable and reliable, easy to control and has a function of over-current protection and automatic recovery.