Switching power supply
View Patent ↗A switching power supply includes an input terminal, a voltage converter, a feedback circuit, and a pulse width modulation (PWM) controller. The input terminal receives a first direct current (DC) voltage. The voltage converter transforms the first DC voltage into a second DC voltage and provides the second DC voltage to a load via transmission lines. The feedback circuit is configured for detecting voltage lost across the transmission lines. The PWM controller controls the voltage converter to adjust the second DC voltage according to the voltage loss.
1. A switching power supply comprising:
an input terminal receiving a first direct current (DC) voltage;
a voltage converter receiving and transforming the first DC voltage into a second DC voltage, and providing the second DC voltage to a load via transmission lines;
a feedback circuit detecting a voltage loss across the transmission lines, wherein the feedback circuit comprises a first resistor, a second resistor, and a reference voltage source, the reference voltage source comprises a control terminal connected to the input terminal via the first resistor, a cathode connected to the input terminal via the first resistor, and an anode grounded via the second resistor; and
a pulse width modulation (PWM) controller providing PWM signal to the voltage converter, and controlling the voltage converter to compensate the second DC voltage according to the voltage loss.
2. The switching power supply of claim 1 , further comprising an output interface connected to the voltage converter, wherein the output interface comprises a first output terminal for outputting the second DC voltage and a second output terminal.
3. The switching power supply of claim 2 , wherein the first output terminal and the second output terminal of the output interface are connected to the load via two transmission lines, correspondingly.
4. The switching power supply of claim 2 , wherein the voltage converter is a buck converter.
5. The switching power supply of claim 4 , wherein the buck converter comprises a transistor, a diode having a cathode and a grounded anode, an inductor, and a capacitor, the input terminal is connected to the cathode of the diode via the transistor, a gate of the transistor is connected to the PWM controller for receiving the PWM signal, the cathode of the diode is connected to the first output terminal of the output interface via the inductor, the first output terminal of the output interface is grounded via the capacitor.
6. The switching power supply of claim 2 , wherein the anode of the reference voltage source is connected to the second output terminal of the output interface.
7. The switching power supply of claim 6 , wherein the PWM controller further comprises a comparator, a noninverting input of the comparator receives a first reference voltage plus a second reference voltage, and an inverting input of the comparator receives the second DC voltage.
8. The switching power supply of claim 7 , wherein the first reference voltage is a voltage between the anode and the cathode of the reference voltage source, and the second reference voltage is a voltage across the second resistor.
9. The switching power supply of claim 7 , wherein the noninverting input of the comparator is connected to the cathode of the reference voltage source.
10. The switching power supply of claim 9 , wherein the PWM controller further comprises a third resistor and a fourth resistor, the inverting input of the comparator is grounded via the fourth resistor, the inverting input of the comparator is connected to the first output terminal of the output interface via the third resistor for receiving the second DC voltage.
11. The switching power supply of claim 10 , wherein an output of the comparator is connected to the voltage converter for providing the PWM signal to the voltage converter.
12. The switching power supply of claim 10 , wherein the PWM controller further comprises a capacitor connected in parallel with the third resistor.
13. A switching power supply comprising:
an input terminal receiving a first direct current (DC) voltage;
a voltage converter receiving and transforming the first DC voltage into a second DC voltage, and providing the second DC voltage to a load via transmission lines, wherein the voltage converter comprises a transistor, a diode having a cathode and a grounded anode, an inductor, and a capacitor, the input terminal is connected to the cathode of the diode via the transistor, a gate of the transistor is connected to the PWM controller for receiving the PWM signal, the cathode of the diode is connected to the first output terminal of the output interface via the inductor, the first output terminal of the output interface is grounded via the capacitor;
a feedback circuit detecting a voltage loss across the transmission lines; and
a pulse width modulation (PWM) controller providing PWM signal to the voltage converter, and controlling the voltage converter to compensate the second DC voltage according to the voltage loss.