Switching power supply circuit

摘要

There is provided a switching power supply circuit (1) for supplying a power supply voltage to a load through a transmission line PL. The switching power supply circuit (1) includes: a voltage conversion unit (11) for inputting thereinto an input voltage VIN and a control signal Vc, converting the input voltage VIN into an output voltage Vo having a magnitude corresponding to the control signal Vc, and outputting the output voltage Vo to the transmission line PL; a signal generation unit (12) for monitoring a load current ILOAD flowing through the transmission line PL and generating a signal corresponding to a voltage dropped in the transmission line PL; and a low pass filter (13) for outputting the signal generated in the signal generation unit (12) to the voltage conversion unit (11) as the control signal Vc.

主权项

1. A switching power supply circuit for supplying a power supply voltage to a load through a transmission line, the switching power supply circuit comprising:
a voltage conversion unit for receiving an input voltage, converting the input voltage into an output voltage having a magnitude corresponding to a control signal, and outputting the output voltage to the transmission line; a signal generation unit for generating a signal corresponding to a voltage to be dropped in the transmission line on the basis of a current flowing through the transmission line, the signal generation unit including a sense resistance electrically connected in series to the transmission line, and a level shift circuit for level-shifting a voltage across both ends of the sense resistance to a voltage based on a reference voltage corresponding to the power supply voltage; and a low pass filter for receiving the signal generated in the signal generation unit, smoothing the input signal, and outputting the control signal to the voltage conversion unit, the low pass filter including a resistance element having one end connected to an output end of the level shift circuit, and a capacitance element having one end connected to the other end of the resistance element, and the other end connected to a reference voltage terminal having the reference voltage.