Low ripple switching power supply for thermoelectric driving based on resonance analysis

A low ripple switching power supply with 0-12 V voltage and 35 A maximum current outputs is developed for the application of high-precision thermoelectric circulating water cooling. In order to suppress the voltage ripple in the output caused by voltage and current spikes generated when the switching mode of full-bridge converter changes, which is further resulted from parasitic capacitance and inductance of MOSFET circuit and rectifier diode circuit in the power supply, resonance analysis and optimization design is carried out. Equivalent models of MOSFET circuit and rectifier diode circuit are established, and absorption circuits are designed to absorb the voltage and current spikes, thus to effectively suppress the voltage ripple in the output of the switching power supply. Experimental results show that the output voltage ripple is reduced from 190 mV to 88 mV after optimization of key parameter.