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CN-122026882-A - Switch control circuit, voltage regulation control system and switch control method

CN122026882ACN 122026882 ACN122026882 ACN 122026882ACN-122026882-A

Abstract

The invention provides a switch control circuit, a voltage regulation control system and a switch control method, wherein the switch control circuit is used in a voltage conversion circuit and comprises a first control module, a second control module and an output selection module, wherein the first control module is used for providing a first control signal, the second control module is used for providing a second control signal, the output selection module is coupled to the output ends of the first control module and the second control module and is used for selecting and outputting the first control signal or the second control signal based on a first instruction signal and a second instruction signal, and when the voltage conversion circuit starts an output voltage regulation function, the output selection module is used for selecting and outputting the second control signal so as to perform discharge control on the output voltage of the voltage conversion circuit. The switch control circuit, the voltage regulating control system and the switch control method solve the problem that the existing voltage regulating scheme is easy to cause output overshoot.

Inventors

  • YU JINTAO
  • BAI ZHIBIN
  • ZHANG HAIBO

Assignees

  • 芯迈半导体技术(杭州)股份有限公司

Dates

Publication Date
20260512
Application Date
20260112

Claims (16)

  1. 1. A switch control circuit for a voltage conversion circuit, comprising: The first control module is used for providing a first control signal; the second control module is used for providing a second control signal; The output selection module is coupled with the output ends of the first control module and the second control module, and selects and outputs the first control signal or the second control signal based on a first instruction signal and a second instruction signal; when the voltage conversion circuit starts the output voltage regulation function, the output selection module selects and outputs the second control signal so as to perform discharge control on the output voltage of the voltage conversion circuit.
  2. 2. The switch control circuit of claim 1, wherein the first control signal is a digital signal having at least two discrete level states and the second control signal is an analog signal having a continuously variable amplitude.
  3. 3. The switch control circuit of claim 1, the output selection module comprising: a logic unit that generates a selection control signal and a transmission control signal based on the first instruction signal and the second instruction signal, wherein the selection control signal and the transmission control signal are a set of inverted signals; and the output selection unit is coupled to the output end of the logic unit and is used for selecting and outputting the first control signal or the second control signal based on the selection control signal.
  4. 4. The switch control circuit of claim 3, the logic unit comprising an and gate, a first not gate, and a second not gate, wherein a first input of the and gate is coupled to the first command signal via the first not gate, a second input of the and gate is coupled to the second command signal, an output of the and gate outputs the selection control signal, and an output of the and gate further outputs the transmission control signal via the second not gate.
  5. 5. The switch control circuit of claim 3, the output selection unit comprising a first transistor and a second transistor, wherein a control terminal of the first transistor is coupled to a first terminal thereof and acts as an output terminal, a first terminal of the first transistor is coupled to the first control signal and the second control signal, a second terminal of the first transistor is coupled to a first terminal of the second transistor, a control terminal of the second transistor is coupled to the selection control signal, and a second terminal of the second transistor is coupled to a ground reference.
  6. 6. The switch control circuit of claim 3, the first control module being controlled by the transmission control signal to provide the first control signal.
  7. 7. The switch control circuit of claim 6, the first control module comprising a transmission gate, wherein the transmission gate transmits the first command signal as the first control signal under control of the transmission control signal.
  8. 8. A switch control circuit as claimed in claim 1 or 3, the second control module comprising a current source, wherein an input of the current source is coupled to an input voltage of the voltage conversion circuit, and an output of the current source provides the second control signal.
  9. 9. The switch control circuit of claim 8 wherein the current source is controlled by a select control signal to start and stop, wherein the second control signal gradually increases from a first preset value to a second preset value when the current source starts to operate, and gradually decreases from the second preset value to the first preset value when the current source stops operating.
  10. 10. A voltage regulation control system for a voltage conversion circuit, comprising the switch control circuit according to any one of claims 1 to 9, further comprising: The rapid discharging circuit comprises at least one rapid discharging module, and is coupled between the output voltage of the voltage conversion circuit and the reference ground; the switch control circuit selectively outputs the first control signal or the second control signal and controls the quick discharging circuit to discharge the output voltage with a first discharging current or a second discharging current.
  11. 11. The voltage regulation control system of claim 10, the fast discharge module comprising a third transistor and a resistor coupled in series between the output voltage of the voltage conversion circuit and a reference ground, wherein a control terminal of the third transistor is coupled to an output terminal of the switch control circuit.
  12. 12. The voltage regulation control system of claim 11, the third transistor and the first transistor in the output selection module form a current mirror, wherein the second discharge current is equal to the second control signal multiplied by a current mirror ratio.
  13. 13. A switch control method for a voltage conversion circuit, comprising: Providing a first control signal and a second control signal respectively; Based on a first instruction signal and a second instruction signal, selecting and outputting the first control signal and the second control signal; When the voltage conversion circuit starts the output voltage regulation function, the second control signal is selected to be output so as to perform discharge control on the output voltage of the voltage conversion circuit; when the voltage conversion circuit starts a quick release function, the first control signal is selected to be output so as to carry out discharge control on the output voltage of the voltage conversion circuit.
  14. 14. The switch control method of claim 13, wherein the output voltage regulation function is turned on when the voltage conversion circuit is idle, and the fast bleeding function is turned on when the voltage conversion circuit is off.
  15. 15. The switch control method of claim 13, wherein the first control signal is a digital signal having at least two discrete level states and the second control signal is an analog signal having a continuously variable amplitude.
  16. 16. The method of claim 15, wherein the voltage converting circuit turns on the output voltage regulating function, the second control signal gradually increases from a first preset value to a second preset value, and the voltage converting circuit turns off the output voltage regulating function, and the second control signal gradually decreases from the second preset value to the first preset value.

Description

Switch control circuit, voltage regulation control system and switch control method Technical Field The present invention relates to the field of electronic circuits, and in particular, to a switch control circuit, a voltage regulation control system, and a switch control method. Background When the output is in the PFM mode, the inductor has only active capability to the output and no discharging capability, so the output can only drop at a slow rate of the electrode through the drain electrode and cannot follow the rate of the voltage regulation. In the existing three solutions, the first is to multiplex a fast discharging circuit (for fast discharging the output to the ground when the chip is shut down) to discharge the output, so as to realize fast voltage regulation under no load, the second is to additionally add a dummy load module for fast voltage regulation under no load, and the third is to add FCCM (forced continuous conduction mode) control, so that the inductor has the discharging capability. Excessive overshoot or undershoot is not desirable when the output is regulated. The first scheme, the multiplexing quick discharging circuit discharges the output in the voltage regulating stage, but the discharge current is larger, so that the output is obviously undershooted, which can be seen in fig. 1, the second scheme, the proper resistor size can be designed to follow the voltage regulating speed, so that the output realizes the voltage regulating process without overshoot smoothly, but extra area consumption is increased, and the third scheme, the output voltage regulating stage is switched from the PFM mode to the FCCM mode, but in the mode switching process, the inductance discharging capacity of the first several periods is too strong, so that the output is obviously undershooted, which can be seen in fig. 1. It should be noted that the foregoing description of the background art is only for the purpose of providing a clear and complete description of the technical solution of the present invention and is presented for the convenience of understanding by those skilled in the art. The above-described solutions are not considered to be known to the person skilled in the art simply because they are set forth in the background of the invention section. Disclosure of Invention In view of the above-mentioned drawbacks of the prior art, an objective of the present invention is to provide a switch control circuit, a voltage regulation control system and a switch control method for solving the problem that the existing voltage regulation scheme is prone to cause output overshoot. To achieve the above and other related objects, the present invention provides a switch control circuit for a voltage converting circuit, comprising: The first control module is used for providing a first control signal; the second control module is used for providing a second control signal; The output selection module is coupled with the output ends of the first control module and the second control module, and selects and outputs the first control signal or the second control signal based on a first instruction signal and a second instruction signal; when the voltage conversion circuit starts the output voltage regulation function, the output selection module selects and outputs the second control signal so as to perform discharge control on the output voltage of the voltage conversion circuit. Optionally, the first control signal is a digital signal having at least two discrete level states, and the second control signal is an analog signal with continuously variable amplitude. Optionally, the output selection module includes: a logic unit that generates a selection control signal and a transmission control signal based on the first instruction signal and the second instruction signal, wherein the selection control signal and the transmission control signal are a set of inverted signals; and the output selection unit is coupled to the output end of the logic unit and is used for selecting and outputting the first control signal or the second control signal based on the selection control signal. Optionally, the logic unit includes an and gate, a first not gate, and a second not gate, where a first input terminal of the and gate is coupled to the first instruction signal via the first not gate, a second input terminal of the and gate is coupled to the second instruction signal, an output terminal of the and gate outputs the selection control signal, and an output terminal of the and gate outputs the transmission control signal via the second not gate. Optionally, the output selecting unit includes a first transistor and a second transistor, wherein a control terminal of the first transistor is coupled to a first terminal thereof and is used as an output terminal, a first terminal of the first transistor is coupled to the first control signal and the second control signal, a second terminal of the first transistor is coupled t