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CN-224217034-U - Linear power supply circuit

CN224217034UCN 224217034 UCN224217034 UCN 224217034UCN-224217034-U

Abstract

The application relates to a linear power supply circuit which comprises a power tube, a first switch tube, a first power supply circuit, a second switch tube, a first resistor and a second power supply circuit, wherein the third end of the first switch tube is coupled with the first end of the power tube, the third end of the second switch tube is coupled with the second end of the first switch tube, the first power supply circuit is coupled with the first end of the first switch tube, the second power supply circuit is coupled with the first end of the second switch tube, the second switch tube is fully conducted in a first mode, the first power supply circuit controls the first switch tube to drive the power tube to output stable first output voltage, and in a second mode, the second power supply circuit uses the first resistor as a current detection resistor to control the second switch tube to drive the power tube to adjust the output voltage so that the second output current flowing through the first resistor is constant. The circuit of the application utilizes the first switching tube, the second switching tube and the power tube to work cooperatively, simplifies the constant voltage and constant current circuit, and realizes free switching between the constant voltage mode and the constant current mode.

Inventors

  • FAN DING

Assignees

  • 苏州华兴源创科技股份有限公司

Dates

Publication Date
20260508
Application Date
20250609

Claims (10)

  1. 1. A linear power circuit having a voltage output, the linear power circuit comprising: A power tube; the third end of the first switch tube is coupled with the first end of the power tube; The output end of the first power supply circuit is coupled with the first end of the first switching tube, and the first power supply circuit is used for controlling the first switching tube to drive the second end of the power tube to generate a first output voltage when receiving a first control signal; a third end of the second switching tube is coupled with the second end of the first switching tube; a first resistor having a first end coupled to the second end of the power tube and a second end coupled to the voltage output end, and The output end of the second power supply circuit is coupled with the first end of the second switching tube, and the second power supply circuit is used for controlling the second switching tube to drive the power tube to generate a second output current on the first resistor when receiving a second control signal; in a first mode, the first power supply circuit receives the first control signal, the second switching tube is completely conducted, and the first output voltage is kept unchanged; in a second mode, the second power supply circuit receives the second control signal, the first switching tube is completely conducted, and the second output current is kept unchanged.
  2. 2. The linear power supply circuit of claim 1, further comprising a first voltage source, the first voltage source being a voltage source that outputs a first negative voltage, the first negative voltage being applied to a third terminal of the power tube.
  3. 3. The linear power supply circuit of claim 1, comprising a second voltage source and a switching circuit, wherein an anode of the second voltage source is coupled to a feedback terminal of the switching circuit, a cathode of the second voltage source is grounded, an output terminal of the switching circuit is coupled to a third terminal of the power tube, and the switching circuit is configured to output a second negative voltage.
  4. 4. The linear power supply circuit of claim 1, wherein the first power supply circuit comprises: The output end of the first operational amplifier is coupled with the first end of the first switching tube, and the inverting input end of the first operational amplifier is coupled with the voltage output end; and the output end of the first power supply circuit is coupled with the non-inverting input end of the first operational amplifier and is used for outputting a first set voltage.
  5. 5. The linear power supply circuit of claim 4, wherein the first power supply circuit comprises: a third voltage source for outputting a first positive voltage; And the inverting input end of the first inverting amplifier is coupled with the positive electrode of the third voltage source, and the output end of the first inverting amplifier is coupled with the non-inverting input end of the first operational amplifier.
  6. 6. The linear power circuit of claim 4, wherein the linear power circuit is configured to power a first load, the linear power circuit further comprising: The input end of the first follower is used for being coupled with the power supply end of the first load, and the output end of the first follower is coupled with the inverting input end of the first operational amplifier; And the input end of the second follower is used for being coupled with the grounding end of the first load, and the output end of the second follower is coupled with the non-inverting input end of the first operational amplifier.
  7. 7. The linear power supply circuit of claim 1, wherein the second power supply circuit comprises: the inverting input end of the second operational amplifier is coupled with the first end of the first resistor, and the non-inverting input end of the second operational amplifier is coupled with the second end of the first resistor; And the output end of the second power supply circuit is coupled with the non-inverting input end of the second operational amplifier, and the second power supply circuit is used for outputting a second set voltage.
  8. 8. The linear power supply circuit of claim 7, wherein the second power supply circuit comprises: a fourth voltage source for outputting a second positive voltage; And the inverting input end of the second inverting amplifier is coupled with the positive electrode of the fourth voltage source, and the output end of the second inverting amplifier is coupled with the non-inverting input end of the second operational amplifier.
  9. 9. The linear power supply circuit of claim 1, wherein a second end of the second switching tube is grounded to achieve a return of the second control signal.
  10. 10. The linear power supply circuit of claim 7, wherein the linear power supply circuit further comprises: the non-inverting input end of the third follower is coupled with the first end of the first resistor, and the output end of the third follower is coupled with the inverting input end of the second operational amplifier; and the non-inverting input end of the fourth follower is coupled with the second end of the first resistor, and the output end of the fourth follower is coupled with the non-inverting input end of the second operational amplifier.

Description

Linear power supply circuit Technical Field The present application relates to the field of power supply circuits, and more particularly, to a linear power supply circuit. Background The current common constant voltage and constant current circuit generally adopts a completely separated design, and the constant voltage and the constant current are operated independently, so that two sets of complete control loops are needed, the number of elements is increased, the PCB layout is more complex, and extra noise and signal delay can be introduced to influence the overall performance. Because the two sets of control loops are mutually independent, when the constant voltage mode and the constant current mode are switched, smooth transition of mode switching is difficult to realize by discrete design, response lag or instantaneous fluctuation is easy to occur, and the stability of the circuit under dynamic load is poor. Disclosure of utility model In view of the above problems, the present application provides a linear power supply circuit having a voltage output terminal, the linear power supply circuit comprising: A power tube; the third end of the first switch tube is coupled with the first end of the power tube; The output end of the first power supply circuit is coupled with the first end of the first switching tube, and the first power supply circuit is used for controlling the first switching tube to drive the second end of the power tube to generate a first output voltage when receiving a first control signal; a third end of the second switching tube is coupled with the second end of the first switching tube; a first resistor having a first end coupled to the second end of the power tube and a second end coupled to the voltage output end, and The output end of the second power supply circuit is coupled with the first end of the second switching tube, and the second power supply circuit is used for controlling the second switching tube to drive the power tube to generate a second output current on the first resistor when receiving a second control signal; in a first mode, the first power supply circuit receives the first control signal, the second switching tube is completely conducted, and the first output voltage is kept unchanged; in a second mode, the second power supply circuit receives the second control signal, the first switching tube is completely conducted, and the second output current is kept unchanged. Further, the linear power supply circuit comprises a first voltage source, wherein the first voltage source is a voltage source for outputting a first negative voltage, and the first negative voltage acts on a third end of the power tube. Further, the linear power supply circuit comprises a second voltage source and a switch circuit, wherein the positive electrode of the second voltage source is coupled with the feedback end of the switch circuit, the negative electrode of the second voltage source is grounded, the output end of the switch circuit is coupled with the third end of the power tube, and the switch circuit is used for outputting a second negative voltage. Further, the first power supply circuit includes: The output end of the first operational amplifier is coupled with the first end of the first switching tube, and the inverting input end of the first operational amplifier is coupled with the voltage output end; and the output end of the first power supply circuit is coupled with the non-inverting input end of the first operational amplifier and is used for outputting a first set voltage. Further, the first power supply circuit includes: a third voltage source for outputting a first positive voltage; And the inverting input end of the first inverting amplifier is coupled with the positive electrode of the third voltage source, and the output end of the first inverting amplifier is coupled with the non-inverting input end of the first operational amplifier. Further, the linear power supply circuit is configured to supply power to a first load, and the linear power supply circuit further includes: The input end of the first follower is used for being coupled with the power supply end of the first load, and the output end of the first follower is coupled with the inverting input end of the first operational amplifier; And the input end of the second follower is used for being coupled with the grounding end of the first load, and the output end of the second follower is coupled with the non-inverting input end of the first operational amplifier. Further, the second power supply circuit includes: the inverting input end of the second operational amplifier is coupled with the first end of the first resistor, and the non-inverting input end of the second operational amplifier is coupled with the second end of the first resistor; And the output end of the second power supply circuit is coupled with the non-inverting input end of the second operational amplifier, and the second power supply ci