Conversion voltage stabilizing circuit and electronic equipment

Abstract

The utility model relates to the technical field of wireless charging, and discloses a conversion voltage stabilizing circuit and electronic equipment, the conversion voltage stabilizing circuit comprises a voltage stabilizing unit, a charging unit, a control unit and a comparison unit, the first power supply end of the voltage stabilizing unit is connected with the voltage stabilizing unit and the charging unit, and the comparison unit is used for detecting the charging voltage of an energy storage device; when the control unit detects that the direct-current driving voltage is lower than a preset power failure protection threshold value, the control unit controls the voltage stabilizing unit to store energy through the voltage of the wireless charging coil, so that the direct-current driving voltage is increased, and the control unit is prevented from entering a power failure state.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electric energy conversion, and particularly to a conversion voltage stabilizing circuit and an electronic device. BACKGROUND

[0002] At present, in the field of wireless charging, the wireless charging coil needs to charge the energy storage unit and supply power to the control logic circuit, and the power supply circuits of the two are isolated. The voltage on the wireless charging coil fluctuates, and when the voltage on the wireless charging coil is low, charging the energy storage unit will cause insufficient power supply to the logic control unit, while the logic control unit will still detect that the charging voltage of the energy storage unit is sufficient, which will cause the logic control unit to enter a power-off restart state. Repeated restarts not only reduce the charging efficiency, but also reduce the service life of electronic components. CONTENT OF THE UTILITY MODEL

[0003] The present application aims to provide a conversion voltage stabilizing circuit and an electronic device, which aims to solve the problem that the logic control unit is restarted when the voltage of the wireless charging coil is unstable in the prior art.

[0004] The present application is implemented in this way. The present application provides a conversion voltage stabilizing circuit, which is used to connect a wireless charging coil and an energy storage device. The wireless charging coil includes a first power supply end and a second power supply end. The second power supply end serves as a ground reference end of the conversion voltage stabilizing circuit. The energy storage device includes a charging end. The conversion voltage stabilizing circuit includes:

[0005] a voltage stabilizing unit, a first input end of the voltage stabilizing unit being used to connect the first power supply end, for generating a direct current driving voltage according to the voltage of the first power supply end;

[0006] a charging unit, an input end of the charging unit being connected with the first power supply end, and an output end of the charging unit being connected with the charging end of the energy storage device;

[0007] a control unit, the control unit being connected with an output end of the voltage stabilizing unit to obtain the direct current driving voltage, and a control end of the control unit being connected with a controlled end of the charging unit;

[0008] a comparison unit, an output end of the comparison unit being connected with the control unit, and input ends of the comparison unit being respectively connected with the first power supply end, the charging end and a preset voltage source;

[0009] The control unit is configured to control the charging unit to charge the energy storage device according to the first power supply end, the charging end and a preset voltage source, and when detecting that the direct-current driving voltage is lower than a preset power-off protection threshold, the control unit is further configured to control the voltage stabilizing unit to raise the direct-current driving voltage by using the voltage of the first power supply end.

[0010] In some embodiments, the voltage stabilizing unit comprises a first switch tube, a voltage stabilizing chip, a first diode and an energy storage capacitor.

[0011] The controlled end of the first switch tube is connected to the control unit, the first end of the first switch tube is connected to the first power supply end and the anode of the first diode respectively, the second end of the first switch tube is connected to the ground reference end, the cathode of the first diode is connected to the input end of the voltage stabilizing chip and the first end of the energy storage capacitor respectively, the output end of the voltage stabilizing chip is connected to the control unit to provide the direct-current driving voltage for the control unit, and the voltage stabilizing chip and the second end of the energy storage capacitor are both connected to the ground reference end.

[0012] In some embodiments, the control unit is configured to perform:

[0013] When detecting that the direct-current driving voltage is lower than a preset power-off protection threshold, a conduction pulse signal is sent to the first switch tube, so that the first power supply end and the second power supply end are only conductive in a pulse interval corresponding to the conduction pulse signal through the first switch tube, so that the wireless charging coil generates an induced voltage, the induced voltage is used to charge the energy storage capacitor, and the charged energy storage capacitor is used to raise the direct-current driving voltage.

[0014] In some embodiments, the charging unit further comprises a second diode, a second switch tube and a filter capacitor.

[0015] The anode of the second diode is connected to the first power supply end, the cathode of the second diode is connected to the first end of the first switch tube, the first end of the second switch tube and the input end of the comparison unit respectively, the controlled end of the second switch tube is connected to the control end of the control unit, the second end of the second switch tube is connected to the charging end and the first end of the filter capacitor respectively, and the second end of the filter capacitor is connected to the ground reference end.

[0016] In some embodiments, the comparison unit comprises a first comparator and a second comparator.

[0017] The non-inverting input end of the first comparator is connected to the cathode of the second diode, the inverting input end of the first comparator is connected to the charging end, and the output end of the first comparator is connected to the control unit.

[0018] The non-inverted input end of the second comparator is connected with the preset voltage source, the inverted input end of the first comparator is connected with the charging end, and the output end of the second comparator is connected with the control unit.

[0019] Only when the first comparator and the second comparator both output high level signals, the control unit sends a conduction signal to the second switch tube to control the charging unit to charge the energy storage device through the electric energy of the wireless charging coil.

[0020] The application further provides an electronic device comprising the conversion voltage stabilizing circuit.

[0021] The application provides a conversion voltage stabilizing circuit for connecting a wireless charging coil and an energy storage device. The wireless charging coil comprises a first power supply end and a second power supply end, and the second power supply end serves as a ground reference end of the conversion voltage stabilizing circuit. The energy storage device comprises a charging end. The conversion voltage stabilizing circuit comprises a voltage stabilizing unit, a charging unit, a control unit and a comparison unit. The first input end of the voltage stabilizing unit is connected with the first power supply end, and is used to generate a direct current driving voltage according to the voltage of the first power supply end. The input end of the charging unit is connected with the first power supply end, and the output end of the charging unit is connected with the charging end of the energy storage device. The output end of the voltage stabilizing unit is connected with the control unit to obtain the direct current driving voltage. The input end of the control unit is connected with the first power supply end, the charging end and a preset voltage source respectively. The control end of the control unit is connected with the controlled end of the charging unit. The output end of the comparison unit is connected with the control unit, and the input end of the comparison unit is connected with the first power supply end, the charging end and the preset voltage source respectively. The control unit is used to control the charging unit to charge the energy storage device according to the first power supply end, the charging end and the preset voltage source. When the direct current driving voltage is detected to be lower than a preset power-off protection threshold value, the control unit is further used to control the voltage stabilizing unit to raise the direct current driving voltage by using the voltage of the first power supply end. The conversion voltage stabilizing circuit has the following beneficial effects:

[0022] 1. The stability of the power supply of the control unit is improved, the control unit is prevented from repeatedly entering a power-off state, the charging efficiency is improved, and the service life of the circuit is improved.

[0023] 2. The energy storage unit is charged with low loss. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 FIG. 1 is a structural schematic diagram of a first conversion voltage stabilizing circuit provided by the application.

[0025] Figure 2 FIG. 2 is a structural schematic diagram of a second conversion voltage stabilizing circuit provided by the application.

[0026] Reference Signs:

[0027] 300, wireless charging coil; 200, energy storage device; 100, conversion voltage stabilization circuit; 11, voltage stabilization unit; Q1, first switch tube; LDO, voltage stabilization chip; D1, first diode; C1, energy storage capacitor; 12, charging unit; D2, second diode; Q2, second switch tube; C2, filter capacitor; 13, control unit; 14, comparison unit; U1, first comparator; U2, second comparator; E1, preset voltage source; VACP, first power supply end; VACN, second power supply end; VO, charging end; VACN, ground reference end. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical scheme and advantages of the present application clearer, the present application is further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application and do not limit the present application.

[0029] The implementation of the present application is described in detail below in combination with specific examples.

[0030] Reference Figure 1 The preferred embodiments of the present application are provided.

[0031] As Figure 1 shown, the present application provides a conversion voltage stabilization circuit 100, which is used to connect a wireless charging coil 300 and an energy storage device 200. The wireless charging coil 300 includes a first power supply end VACP and a second power supply end VACN, and the second power supply end VACN serves as a ground reference end VACN of the conversion voltage stabilization circuit 100. The energy storage device 200 includes a charging end VO. The conversion voltage stabilization circuit 100 includes a voltage stabilization unit 11, a charging unit 12, a control unit 13 and a comparison unit 14.

[0032] The first input end of the voltage stabilization unit 11 is used to connect the first power supply end VACP, and is used to generate a direct current driving voltage (VCC and VDD) according to the voltage of the first power supply end VACP.

[0033] The input end of the charging unit 12 is connected with the first power supply end VACP, and the output end of the charging unit 12 is connected with the charging end VO of the energy storage device 200.

[0034] The control unit 13 is connected with the output end of the voltage stabilization unit 11 to obtain the direct current driving voltage (VCC and VDD), and the control end of the control unit 13 is connected with the controlled end of the charging unit 12.

[0035] The output of the comparison unit 14 is connected to the control unit 13, and the input of the comparison unit 14 is connected to the first power supply end VACP, the charging end VO and the preset voltage source E1 respectively.

[0036] It should be noted that if the first power supply end VACP and the charging end VO are provided with a voltage dividing resistor, the voltage of the first power supply end VACP and the voltage of the charging end VO are both the voltage after voltage division.

[0037] The control unit 13 is configured to control the charging unit 12 to charge the energy storage device 200 according to the first power supply end VACP, the charging end VO and the preset voltage source E1. When the detection result of the DC driving voltage (VCC and VDD) is lower than the preset power-off protection threshold, the control unit 13 is further configured to control the voltage stabilizing unit 11 to increase the DC driving voltage (VCC and VDD) by using the voltage of the first power supply end VACP. It should be noted that in the embodiment of the present application, the voltage stabilizing unit 11 is used to increase the DC driving voltage (VCC and VDD) only when the peak voltage of the first power supply end VACP is less than the preset power supply threshold.

[0038] For example, the voltage stabilizing unit 11 includes an energy storage element, and when the detection result of the DC driving voltage (VCC and VDD) is lower than the preset power-off protection threshold, the control unit 13 controls the voltage stabilizing unit 11 to generate an induced voltage in the wireless charging coil 300, so that when the energy storage element is charged, the voltage output to the charging unit 12 will not be too low, and the charging process of the charging unit 12 can be maintained.

[0039] The present application provides a conversion voltage stabilizing circuit for connecting a wireless charging coil and an energy storage device. The wireless charging coil includes a first power supply end and a second power supply end, and the second power supply end is used as a ground reference end of the conversion voltage stabilizing circuit. The energy storage device includes a charging end. The conversion voltage stabilizing circuit includes a voltage stabilizing unit, a charging unit, a control unit and a comparison unit. The first input end of the voltage stabilizing unit is connected to the first power supply end, and is configured to generate a DC driving voltage according to the voltage of the first power supply end. The input end of the charging unit is connected to the first power supply end, and the output end of the charging unit is connected to the charging end of the energy storage device. The output end of the voltage stabilizing unit is connected to the control unit, and the input end of the control unit is connected to the first power supply end, the charging end and a preset voltage source respectively. The control end of the control unit is connected to the controlled end of the charging unit. The control unit is configured to control the charging unit to charge the energy storage device according to the first power supply end, the charging end and the preset voltage source. When the detection result of the DC driving voltage is lower than the preset power-off protection threshold, the control unit is further configured to control the voltage stabilizing unit to increase the DC driving voltage by using the voltage of the first power supply end. The conversion voltage stabilizing circuit has the following advantages:

[0040] 1. The stability of the power supply to the control unit is provided, the control unit is prevented from repeatedly entering the power-off state, the charging efficiency is improved, and the circuit life is also improved.

[0041] 2. The energy storage unit is charged with lower loss.

[0042] In order to more clearly introduce the technical scheme of the present application, the technical scheme of the present application will be introduced through specific embodiments below. It should be noted that the specific embodiments are used to expand the description of the technical scheme of the present application, and are not intended to limit the present application.

[0043] In some embodiments, the voltage stabilizing unit 11 includes a first switch tube Q1, a voltage stabilizing chip LDO, a first diode D1, and an energy storage capacitor C1. The controlled end of the first switch tube Q1 is connected with the control unit 13, the first end of the first switch tube Q1 is connected with the first power supply end VACP and the anode of the first diode respectively, and the second end of the first switch tube Q1 is connected with the ground reference end VACN. The cathode of the first diode is connected with the input end of the voltage stabilizing chip LDO and the first end of the energy storage capacitor C1 respectively. The output end of the voltage stabilizing chip LDO is connected with the control unit 13 to provide a direct current driving voltage (VCC and VDD) to the control unit 13, and the second end of the voltage stabilizing chip LDO and the energy storage capacitor C1 are both connected with the ground reference end VACN.

[0044] In some embodiments, the charging unit 12 further includes a second diode D2, a second switch tube Q2, and a filter capacitor C2.

[0045] The anode of the second diode D2 is connected with the first power supply end VACP, the cathode of the second diode D2 is connected with the first end of the first switch tube Q1, the first end of the second switch tube Q2, and the input end of the comparison unit 14 respectively, the controlled end of the second switch tube Q2 is connected with the control end of the control unit 13, the second end of the second switch tube Q2 is connected with the charging end VO and the first end of the filter capacitor C2 respectively, and the second end of the filter capacitor C2 is connected with the ground reference end VACN.

[0046] It should be noted that the functions of the first diode and the second diode D2 are to prevent voltage backflow, wherein the first diode is used to prevent voltage backflow of the energy storage capacitor C1, and the second diode D2 is used to prevent voltage backflow of the energy storage device 200. Since the power supply voltage of the first power supply end VACP is lowered by the conduction voltage drop of the second diode D2 and is lowered to VPD, in order to facilitate description, the voltage (VPD) at the cathode of the second diode D2 is taken as the power supply voltage VPD of the wireless charging coil 300 in the following.

[0047] In some embodiments, the control unit 13 is configured to perform the following: when detecting that the direct current driving voltage (VCC and VDD) is lower than a preset power-off protection threshold, sending a conduction pulse signal to the first switch tube Q1 to make the first power supply end VACP and the second power supply end VACN conduct only in the pulse interval corresponding to the conduction pulse signal through the first switch tube Q1, so that the wireless charging coil 300 generates an induced voltage, and the induced voltage is used to charge the energy storage capacitor C1, and the charged energy storage capacitor C1 is used to increase the direct current driving voltage (VCC and VDD).

[0048] For example, when the supply voltage of the wireless charging coil 300 fluctuates. The wireless charging coil 300 has inductance characteristics, and when the supply current increases, the supply voltage decreases, and an induced voltage is generated. The pulse interval of the conduction pulse signal is set in the positive half-wave interval where the voltage of the first power supply end VACP is greater than 0V, for example, when the frequency of the voltage change of the first power supply end VACP is 500kHz, the pulse interval of the conduction pulse signal is within 1us. At the same time, the pulse interval of the conduction pulse signal can also be set through a feedback mechanism, for example, the induced voltage or induced current is detected through the feedback mechanism and transmitted to the control unit, and when the induced voltage or induced current is greater than a preset induction threshold, it means that the charging demand of the energy storage capacitor C1 has been met, and the control unit 13 stops outputting the pulse signal. By controlling the first switch tube Q1 to conduct for a short time, the first power supply end VACP and the second power supply end VACN are temporarily turned on, so that the wireless charging coil 300 generates an induced voltage or an induced current. The energy storage capacitor C1 is charged by the induced voltage or the induced current. In specific applications, the effect of charging the energy storage capacitor C1 by detecting and controlling the size of the induced current will be better. After the first switch tube Q1 is turned off, the energy storage capacitor C1 and the supply voltage jointly supply power to the voltage stabilizing chip LDO, thereby increasing the direct current driving voltage (VCC and VDD).

[0049] Through the above circuit setting, the stability of the power supply of the control unit 13 is improved, the control unit 13 is prevented from repeatedly entering the power-off state, the charging efficiency is improved, and the service life of the circuit is also improved.

[0050] At the same time, the induced voltage exists for a certain period of time, and the charging unit 12 can also continue to charge. Compared with the prior art of isolating the charging unit 12 and the voltage stabilizing unit 11, the charging efficiency is improved.

[0051] In some embodiments, the comparison unit 14 includes a first comparator U1 and a second comparator U2. The non-inverting input of the first comparator U1 is connected to the cathode of the second diode D2, the inverting input of the first comparator U1 is connected to the charging terminal VO, and the output of the first comparator U1 is connected to the control unit 13. The non-inverting input of the second comparator U2 is connected to the preset voltage source E1, the inverting input of the second comparator U2 is connected to the charging terminal VO, and the output of the second comparator U2 is connected to the control unit 13. Only when both the first comparator U1 and the second comparator U2 output high level signals, the control unit 13 sends a conduction signal to the second switch tube Q2 to control the charging unit 12 to charge the energy storage device 200 through the wireless charging coil 300.

[0052] For example, the preset voltage source E1 provides a reference voltage Vref. The second power supply terminal VACN is used as the ground reference terminal VACN of the conversion voltage stabilizing circuit 100. The voltage at the negative electrode of the second diode D2 is used as the power supply voltage VPD. The first comparator U1 is used to determine the magnitude of the power supply voltage VPD and the voltage VO at the charging terminal VO, and outputs a high level signal when the power supply voltage VPD is greater than the voltage VO at the charging terminal VO. The second comparator U2 is used to determine the magnitude of the reference voltage Vref and the voltage VO at the charging terminal VO, and outputs a high level signal when the reference voltage Vref is greater than the voltage VO at the charging terminal VO. The control unit 13 uses the two high level signals as the condition for controlling the charging. When the power supply voltage VPD is greater than the voltage VO at the charging terminal VO and the voltage VO at the charging terminal VO is less than the reference voltage Vref, the energy storage device 200 can be directly charged by the power supply voltage VPD. Moreover, the charging of the energy storage device 200 is stopped when the voltage VO at the charging terminal VO reaches the reference voltage Vref, so during the charging process, the alternating voltage for charging is VF+VPD=VF+Ron*I+VO, where VF is the forward conduction voltage of the second diode D2, Ron is the resistance of the second switch tube Q2, and I is the charging current.

[0053] It should be noted that if the negative electrode of the second diode D2 is provided with a voltage dividing resistor, the voltage at the negative electrode of the second diode D2 is the voltage after voltage division.

[0054] In the conversion voltage stabilizing circuit 100 provided in the present application, only one charging switch (the second switch tube Q2) needs to be controlled, and compared with the prior art, the control logic is simple, and at the same time, in terms of power consumption, the power consumption P1 of the conversion voltage stabilizing circuit 100 in each charging period is P1=VF*I+Ron*I 2 , which is less than the power P2 of the prior art, P2=Ron(SW1)*I 2 +Ron(SW3)*I 2The power consumption of the conversion voltage stabilizing circuit 100 can be lower.

[0055] Through the above power supply mode, the voltage V0 of the charging end V0 is less than the peak voltage of the wireless charging coil 300, so that the effect of reducing power loss is achieved.

[0056] In addition, since the second power supply end VACN is directly used as the ground reference end VACN, compared with the circuit in the prior art which needs to additionally set the ground end GND, the technical solution of the present application is easier to implement and the circuit structure is simpler. At the same time, since it is not necessary to judge the positive and negative phases of the alternating current of the wireless charging coil 300, the number of comparators used is reduced, and the circuit is further simplified.

[0057] The present application also provides an electronic device comprising the conversion voltage stabilizing circuit according to any one of the embodiments of the present application.

[0058] The above merely provides the preferred embodiments of the present application but not for limiting the present application. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A conversion regulator circuit, characterized by comprising: The conversion voltage stabilization circuit is used for connecting a wireless charging coil and an energy storage device, the wireless charging coil comprises a first power supply end and a second power supply end, the second power supply end is used as a ground reference end of the conversion voltage stabilization circuit, the energy storage device comprises a charging end, and the conversion voltage stabilization circuit comprises: a voltage stabilization unit, a first input end of the voltage stabilization unit is used for connecting the first power supply end, and a direct current driving voltage is generated according to a voltage of the first power supply end; a charging unit, an input end of the charging unit is connected with the first power supply end, and an output end of the charging unit is connected with the charging end of the energy storage device; a control unit, the control unit is connected with an output end of the voltage stabilization unit to obtain the direct current driving voltage, and a control end of the control unit is connected with a controlled end of the charging unit; a comparison unit, an output end of the comparison unit is connected with the control unit, and input ends of the comparison unit are respectively connected with the first power supply end, the charging end and a preset voltage source; wherein, the control unit is used for controlling the charging unit to charge the energy storage device according to the first power supply end, the charging end and the preset voltage source, and when it is detected that the direct current driving voltage is lower than a preset power-off protection threshold value, the control unit is further used for controlling the voltage stabilization unit to raise the direct current driving voltage by using the voltage of the first power supply end.

2. The conversion regulator circuit of claim 1, wherein, The voltage stabilization unit comprises a first switch tube, a voltage stabilization chip, a first diode and an energy storage capacitor. The controlled end of the first switch tube is connected with the control unit, the first end of the first switch tube is respectively connected with the first power supply end and the anode of the first diode, the second end of the first switch tube is connected with the ground reference end, the cathode of the first diode is respectively connected with the input end of the voltage stabilization chip and the first end of the energy storage capacitor, the output end of the voltage stabilization chip is connected with the control unit to provide the direct current driving voltage for the control unit, and the second ends of the voltage stabilization chip and the energy storage capacitor are both connected with the ground reference end.

3. The conversion regulator circuit of claim 2, wherein, The control unit is used for performing: when it is detected that the direct current driving voltage is lower than a preset power-off protection threshold value, a conduction pulse signal is sent to the first switch tube to make the first power supply end and the second power supply end only conduct in a pulse interval corresponding to the conduction pulse signal through the first switch tube, so that the wireless charging coil generates an induced voltage, the induced voltage is used for charging the energy storage capacitor, and the charged energy storage capacitor is used for raising the direct current driving voltage.

4. The conversion regulator circuit of claim 2, wherein, The charging unit further comprises a second diode, a second switch tube and a filter capacitor. The anode of the second diode is connected with the first power supply end, the cathode of the second diode is respectively connected with the first end of the first switch tube, the first end of the second switch tube and the input end of the comparison unit, the controlled end of the second switch tube is connected with the control end of the control unit, the second end of the second switch tube is respectively connected with the charging end and the first end of the filter capacitor, and the second end of the filter capacitor is connected with the ground reference end.

5. The conversion regulator circuit of claim 4, wherein, The comparison unit comprises a first comparator and a second comparator; a non-inverted input end of the first comparator is connected with a cathode of the second diode, an inverted input end of the first comparator is connected with the charging end, and an output end of the first comparator is connected with the control unit; a non-inverted input end of the second comparator is connected with the preset voltage source, an inverted input end of the first comparator is connected with the charging end, and an output end of the second comparator is connected with the control unit; only when high level signals are output by the first comparator and the second comparator, the control unit sends a conduction signal to the second switch tube to control the charging unit to charge the energy storage device through the electric energy of the wireless charging coil.

6. An electronic device, comprising: The electronic device comprises the conversion voltage stabilization circuit according to any one of claims 1-5.

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