Constant current source voltage regulating power supply circuit, method and PD power supply

Abstract

A constant current source voltage regulating power supply circuit, method and PD power source, by reading the voltage change of the feedback resistance of the AC / DC circuit under the action of the voltage regulating constant current source signal, the voltage of the feedback resistance of the AC / DC circuit is adjusted, so that the output voltage of the AC / DC circuit is indirectly adjusted by the voltage regulating constant current signal to follow the output demand voltage of the DC / DC circuit, thereby realizing the synchronous adjustment of the output voltage of the DC / DC circuit and the AC / DC circuit by the voltage regulating constant current signal; when the output demand voltage is lower than the initial voltage of the AC / DC circuit, the pass-through circuit is turned off, and at the same time the voltage following function is disconnected to maintain the initial voltage of the output voltage of the AC / DC circuit; when the output demand voltage is not lower than the initial voltage of the AC / DC circuit, the pass-through circuit is turned on, and at the same time the voltage following function is turned on so that the output voltage of the AC / DC circuit is regulated by the voltage regulating constant current source signal, thereby realizing the synchronous regulation of the DC / DC pass-through and the AC / DC under the open loop protocol when the high voltage gear is output, thereby improving the overall efficiency.

Description

Technical Field

[0001] This invention relates to the field of power supplies, and more particularly to a constant current source voltage regulation power supply circuit, method, and PD power supply. Background Technology

[0002] Due to the significant improvement in self-regulation compared to traditional USB power supplies, PD power supplies offer increasingly diverse outputs, including dynamic output voltages and currents up to 5A. Given this diversity, most power supply topologies are AC / DC + DC / DC (one or more channels), with the additional DC / DC stage further reducing efficiency. Since the maximum output current is typically 3A-5A, higher output voltage results in higher output power and greater heat generation. Therefore, at high power levels, DC / DC bypass is preferred to improve overall efficiency. However, conventional protocols do not support DC / DC bypass and synchronous AC / DC voltage regulation. While some custom chips may achieve this, these are typically tied to the protocol, leading to high costs, supply difficulties, and inflexible solution selection. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a constant current source voltage regulation power supply circuit, method and PD power supply in view of the above-mentioned defects of the prior art.

[0004] The technical solution adopted by this invention to solve its technical problem is:

[0005] On one hand, a constant current source voltage-regulating power supply circuit is constructed, including an AC / DC circuit and at least one DC / DC circuit connected to the downstream stage of the AC / DC circuit. The DC / DC circuit receives a voltage-regulating constant current source signal and applies it to the voltage change of a feedback resistor to adjust its own output voltage. The constant current source voltage-regulating power supply circuit is characterized by further including, for each of the DC / DC circuits:

[0006] A through circuit, connected in parallel with a corresponding DC / DC circuit, is used to directly output the output voltage of the AC / DC circuit when it is turned on;

[0007] A voltage follower and pass-through extraction circuit is connected between the output feedback side of the AC / DC circuit and the output feedback side of the DC / DC circuit, and also connected to the controlled terminal of the pass-through circuit. It is used to open the pass-through circuit when the output demand voltage of the DC / DC circuit is not lower than the initial voltage of the AC / DC circuit, and to read the voltage change of the feedback resistor of the DC / DC circuit under the action of the voltage-regulating constant current source signal to adjust the voltage of the feedback resistor of the AC / DC circuit, so that the voltage-regulating constant current signal indirectly regulates the output voltage of the AC / DC circuit to follow the output demand voltage of the DC / DC circuit. When the output demand voltage of the DC / DC circuit is lower than the initial voltage of the AC / DC circuit, the pass-through circuit is turned off, and the following effect on the output demand voltage of the DC / DC circuit is disconnected, so that the output voltage of the AC / DC circuit maintains the initial voltage.

[0008] Furthermore, in the constant current source voltage regulation power supply circuit of the present invention, the voltage follower and direct-through extraction circuit includes:

[0009] An emitter follower circuit is connected between the output feedback side of the AC / DC circuit and the output feedback side of the DC / DC circuit. It is used to apply the voltage change of the feedback resistor of the DC / DC circuit to the feedback resistor of the AC / DC circuit so that the output voltage of the AC / DC circuit follows the output demand voltage of the DC / DC circuit.

[0010] A unidirectional switching circuit is disposed in the output path of the emitter follower circuit and connected to the controlled terminal of the direct circuit. It is used to turn off the direct circuit and disconnect the emitter follower circuit to maintain the output voltage of the AC / DC circuit at the initial voltage when the output demand voltage of the DC / DC circuit is lower than the initial voltage of the AC / DC circuit. When the output demand voltage of the DC / DC circuit is not lower than the initial voltage of the AC / DC circuit, it turns on the direct circuit and the emitter follower circuit.

[0011] Furthermore, in the constant current source voltage regulation power supply circuit described in this invention,

[0012] The DC / DC circuit includes a DC / DC chip, a first resistor, a second resistor, and a third resistor. The first end of the first resistor is connected to the voltage output pin of the DC / DC chip. The second end of the first resistor is connected to the first end of the second resistor and receives the voltage-regulating constant current source signal. The second end of the second resistor and the first end of the third resistor are connected to the feedback pin of the DC / DC chip. The second end of the third resistor is connected to the DC output ground.

[0013] The AC / DC circuit includes an AC / DC chip, a fourth resistor, a fifth resistor, and a sixth resistor. The first end of the fourth resistor is connected to the voltage output pin of the AC / DC chip, the second end of the fourth resistor is connected to the first end of the fifth resistor, the second end of the fifth resistor and the first end of the sixth resistor are connected to the feedback pin of the AC / DC chip, and the second end of the sixth resistor is connected to the DC output ground.

[0014] The resistance values ​​of the second and third resistors and the fifth and sixth resistors satisfy the following: when the feedback pins of the AC / DC chip and the DC / DC chip reach their respective set feedback values, the difference between the voltage at the first end of the second resistor and the voltage at the first end of the fifth resistor is the preset deviation voltage.

[0015] The emitter follower circuit is a differential amplifier circuit. The differential input of the emitter follower circuit is connected to the second and first terminals of the first resistor, and the differential output is connected to the first and second terminals of the fourth resistor, respectively. It is used to emitter follower the voltage at the two terminals of the first resistor onto the voltage at the two terminals of the fourth resistor.

[0016] Furthermore, in the constant current source voltage regulation power supply circuit described in this invention, the preset deviation voltage is 0.2V.

[0017] Furthermore, in the constant current source voltage regulation power supply circuit of the present invention, the emitter follower circuit includes an operational amplifier, a seventh resistor, an eighth resistor, a ninth resistor, and a tenth resistor. The inverting input terminal of the operational amplifier is connected to the first terminal of the first resistor via the eighth resistor. The inverting input terminal of the operational amplifier is also connected to the second terminal of the fourth resistor via the seventh resistor. The non-inverting input terminal of the operational amplifier is connected to the second terminal of the first resistor via the ninth resistor. The non-inverting input terminal of the operational amplifier is also connected to the first terminal of the fourth resistor via the tenth resistor. The unidirectional switching circuit is connected between the second terminal of the fourth resistor and the output terminal of the operational amplifier.

[0018] Furthermore, in the constant current source voltage regulation power supply circuit of the present invention, the unidirectional switching circuit includes an NPN transistor, the base of the transistor is connected to the second terminal of the fourth resistor, the emitter of the transistor is connected to the output terminal of the operational amplifier, and the collector of the transistor is connected to the through circuit.

[0019] Furthermore, in the constant current source voltage regulation power supply circuit of the present invention, the through circuit includes a MOSFET, an eleventh resistor and a twelfth resistor. The MOSFET is connected between the voltage output pin of the AC / DC chip and the voltage output pin of the DC / DC chip. The gate of the MOSFET is connected to the collector of the transistor via the twelfth resistor. The eleventh resistor is connected between the source and the gate of the MOSFET.

[0020] Secondly, a PD power supply is constructed, including the constant current source voltage regulation power supply circuit as described above.

[0021] Thirdly, a constant current source power supply control method is constructed, based on the aforementioned constant current source voltage regulation power supply circuit, the method comprising:

[0022] The DC / DC circuit receives the voltage-regulating constant current source signal and applies it to the voltage change of the feedback resistor to adjust its own output voltage.

[0023] When the output demand voltage of the DC / DC circuit is not lower than the initial voltage of the AC / DC circuit, the voltage follower and pass-through extraction circuit opens the pass-through circuit and reads the voltage change of the feedback resistor of the DC / DC circuit under the action of the voltage-regulating constant current source signal to adjust the voltage of the feedback resistor of the AC / DC circuit, so that the voltage-regulating constant current signal indirectly adjusts the output voltage of the AC / DC circuit to follow the output demand voltage of the DC / DC circuit.

[0024] When the output demand voltage of the DC / DC circuit is lower than the initial voltage of the AC / DC circuit, the voltage follower and direct extraction circuit turns off the direct circuit and disconnects the following effect on the output demand voltage of the DC / DC circuit, so that the output voltage of the AC / DC circuit maintains the initial voltage.

[0025] The constant current source voltage regulation power supply circuit, method, and PD power supply of the present invention have the following beneficial effects: This application adjusts the voltage of the feedback resistor of the AC / DC circuit by reading the voltage change of the feedback resistor of the DC / DC circuit under the action of the voltage regulation constant current source signal, so that the voltage regulation constant current source signal indirectly regulates the output voltage of the AC / DC circuit, thereby realizing the synchronous regulation of the output voltage of the DC / DC circuit and the AC / DC circuit by the voltage regulation constant current source signal; when the output demand voltage of the DC / DC circuit is lower than the initial voltage of the AC / DC circuit, that is, when the DC / DC circuit is stepping down, the pass-through circuit is turned off, and the voltage follower function is turned off so that the output voltage of the AC / DC circuit is maintained at the initial voltage. In this case, it is equivalent to relying on the DC / DC circuit for step-down output; when the output demand voltage of the DC / DC circuit is not lower than the initial voltage of the AC / DC circuit, the pass-through circuit is turned on, and the voltage follower function is turned on so that the voltage regulation constant current source signal indirectly regulates the output voltage of the AC / DC circuit, that is, the voltage followed by the AC / DC circuit is directly passed through for output. In this way, the DC / DC pass-through and AC / DC synchronous voltage regulation are realized when the high voltage level output is under the open-loop protocol, thereby improving the overall efficiency. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort:

[0027] Figure 1 This is a block diagram of the constant current source voltage regulation power supply circuit of the present invention;

[0028] Figure 2 This is a circuit diagram of a specific embodiment of the constant current source voltage regulation power supply circuit of the present invention. Detailed Implementation

[0029] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Typical embodiments of the invention are shown in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to make the disclosure of the present invention more thorough and complete. It should be understood that the embodiments of the present invention and the specific features thereof are detailed descriptions of the technical solutions of this application, and not limitations thereof. Where there is no conflict, the embodiments of the present invention and the technical features thereof can be combined with each other.

[0030] refer to Figure 1 The constant current source voltage regulator circuit of the present invention includes an AC / DC circuit 1 and at least one DC / DC circuit 2 connected to the stage following the AC / DC circuit 1. It also includes, for each of the DC / DC circuits 2, a pass-through circuit 3 and a voltage follower and pass-through extraction circuit 4. The input of the DC / DC circuit 2 is connected to the output of the AC / DC circuit 1, and the DC / DC circuit 2 is used to convert the output of the AC / DC circuit 1 to DC / DC conversion before outputting it. The pass-through circuit 3 is connected in parallel with the corresponding DC / DC circuit 2 and is used to directly output the output voltage of the AC / DC circuit 1 when it is turned on.

[0031] In this circuit, DC / DC circuit 2 uses closed-loop feedback control, with the feedback voltage of the feedback resistor reaching a set feedback value as the control objective. Specifically, DC / DC circuit 2 samples the output voltage through the feedback resistor, compares the feedback voltage with the feedback value, and adjusts the output voltage accordingly. If the feedback voltage is lower than the feedback value, the output voltage is increased; if it is higher, the output voltage is decreased. In practical applications, different loads require different output voltages. Therefore, a regulated constant current source signal can be sent to the feedback resistor via a protocol to adjust the output of DC / DC circuit 2 to meet the required output voltage. For example, if a higher output voltage is required, a regulated constant current source signal can be output and superimposed on the feedback voltage of the feedback resistor, effectively reducing the actual feedback voltage and thus increasing the output voltage of DC / DC circuit 2. Conversely, if a lower output voltage is required, a regulated constant current source signal can be output and superimposed on the feedback voltage of the feedback resistor, effectively increasing the actual feedback voltage and thus decreasing the output voltage of DC / DC circuit 2.

[0032] Similarly, AC / DC circuit 1 also uses closed-loop feedback control, with the feedback voltage of the feedback resistor reaching a set feedback value as the control target. Specifically, AC / DC circuit 1 samples the output voltage through the feedback resistor, compares the feedback voltage of the feedback resistor with the feedback value, and increases the output voltage if the voltage is lower than the feedback value, and decreases the output voltage if the voltage is higher than the feedback value.

[0033] The voltage follower and direct-through extraction circuit 4 of the present invention is connected between the output feedback side of the AC / DC circuit 1 and the output feedback side of the DC / DC circuit 2, and is also connected to the controlled terminal of the direct-through circuit 3. It is used to open the direct-through circuit 3 when the output demand voltage of the DC / DC circuit 2 is not lower than the initial voltage of the AC / DC circuit 1, and to read the voltage change of the feedback resistor of the DC / DC circuit 2 under the action of the voltage-regulating constant current source signal to adjust the voltage of the feedback resistor of the AC / DC circuit 1, so that the voltage-regulating constant current source signal indirectly regulates the output voltage of the AC / DC circuit 1, making the output voltage of the AC / DC circuit 1 follow the output demand voltage of the DC / DC circuit 2; when the output demand voltage of the DC / DC circuit 2 is lower than the initial voltage of the AC / DC circuit 1, it turns off the direct-through circuit 3 and disconnects the following of the output demand voltage of the DC / DC circuit 2, so that the output voltage of the AC / DC circuit 1 maintains the initial voltage.

[0034] refer to Figure 2 The voltage follower and direct extraction circuit 4 in this embodiment includes an emitter follower circuit 41 and a one-way switching circuit 42.

[0035] An emitter follower circuit 41 is connected between the output feedback side of the AC / DC circuit 1 and the output feedback side of the DC / DC circuit 2. It is used to apply the voltage change of the feedback resistor of the DC / DC circuit 2 to the feedback resistor of the AC / DC circuit 1, causing the output voltage of the AC / DC circuit 1 to follow the output demand voltage of the DC / DC circuit 2. In other words, the purpose of the emitter follower circuit 41 is to allow the output demand voltage of the DC / DC circuit 2 to drive the output of the AC / DC circuit 1 to rise, rather than stabilizing it at the initial voltage. If the emitter follower circuit 41 stops working, the output voltage of the AC / DC circuit 1 will return to its initial voltage.

[0036] A one-way switching circuit 42 is disposed in the output path of the emitter follower circuit 41 and connected to the controlled terminal of the direct circuit 3. It is used to turn off the direct circuit 3 and disconnect the emitter follower circuit 41 when the output demand voltage of the DC / DC circuit 2 is lower than the initial voltage of the AC / DC circuit 1 so that the output voltage of the AC / DC circuit 1 is maintained at the initial voltage. When the output demand voltage of the DC / DC circuit 2 is not lower than the initial voltage of the AC / DC circuit 1, it turns on the direct circuit 3 and the emitter follower circuit 41.

[0037] The specific circuit of this embodiment is described below, and the working principle of this embodiment is explained in detail with reference to the specific circuit.

[0038] The DC / DC circuit 2 in this embodiment includes a DC / DC chip, a first resistor R3, a second resistor R4, and a third resistor R5. The AC / DC circuit 1 includes an AC / DC chip, a fourth resistor R9, a fifth resistor R12, and a sixth resistor R13. The first end of the first resistor R3 is connected to the voltage output pin of the DC / DC chip. The second end of the first resistor R3 is connected to the first end of the second resistor R4 and receives the voltage-regulating constant current source signal. The second ends of the second resistor R4 and the first ends of the third resistor R5 are connected to the feedback pin of the DC / DC chip. The second end of the third resistor R5 is connected to the DC output ground AGND. The first end of the fourth resistor R9 is connected to the voltage output pin of the AC / DC chip. The second end of the fourth resistor R9 is connected to the first end of the fifth resistor R12. The second ends of the fifth resistor R12 and the first ends of the sixth resistor R13 are connected to the feedback pin of the AC / DC chip. The second end of the sixth resistor R13 is connected to the DC output ground AGND.

[0039] The resistance values ​​of the second resistor R4, the third resistor R5, the fifth resistor R12, and the sixth resistor R13 satisfy the following condition: when the feedback pins of the AC / DC chip and the DC / DC chip reach their respective set feedback values, the difference between the voltage Vdc-fb at the first terminal of the second resistor R4 and the voltage Vac-fb at the first terminal of the fifth resistor R12 is the preset deviation voltage. That is, the voltage Vdc-fb at the first terminal of the second resistor R4 and the voltage Vac-fb at the first terminal of the fifth resistor R12 are approximately the same. This is because the set feedback value for the AC / DC chip differs from the set feedback value for the DC / DC chip. Therefore, resistors R12 and R4 are added to make the feedback voltage Vac-fb approximately the same as Vdc-fb. Currently, Vac-fb is designed to be slightly lower than Vdc-fb, for example, 0.2V lower, meaning the preset deviation voltage is 0.2V. The purpose of this design is to ensure that the DC / DC output voltage is low during direct connection, so that the DC / DC feedback is too low and remains in 100% operating mode.

[0040] In this embodiment, the emitter follower circuit 41 is a differential amplifier circuit with an amplification ratio of 1:1. The differential input of the emitter follower circuit 41 is connected to the second and first ends of the first resistor R3, and the differential output is connected to the first and second ends of the fourth resistor R9. The emitter follower circuit 41 is used to emit the voltage across the body of the first resistor R3 onto the voltage across the body of the fourth resistor R9.

[0041] More specifically, the emitter follower circuit 41 includes an operational amplifier IC1A, a seventh resistor R7, an eighth resistor R8, a ninth resistor R10, and a tenth resistor R11. The inverting input terminal of the operational amplifier IC1A is connected to the first terminal of the first resistor R3 via the eighth resistor R8. The inverting input terminal of the operational amplifier IC1A is also connected to the second terminal of the fourth resistor R9 via the seventh resistor R7. The non-inverting input terminal of the operational amplifier IC1A is connected to the second terminal of the first resistor R3 via the ninth resistor R10. The non-inverting input terminal of the operational amplifier IC1A is also connected to the first terminal of the fourth resistor R9 via the tenth resistor R11. The unidirectional switch circuit 42 is connected between the second terminal of the fourth resistor R9 and the output terminal of the operational amplifier IC1A.

[0042] Preferably, the unidirectional switching circuit 42 includes an NPN transistor Q2, the base of which is connected to the second terminal of the fourth resistor R9, the emitter of which is connected to the output terminal of the operational amplifier IC1A, and the collector of which is connected to the pass-through circuit 3. It is understood that the unidirectional switching circuit 42 can also be implemented using a diode.

[0043] The through circuit 3 in this embodiment includes a MOSFET Q1, an eleventh resistor R1, and a twelfth resistor R2. The MOSFET Q1 is connected between the voltage output pin of the AC / DC chip and the voltage output pin of the DC / DC chip. The gate of the MOSFET Q1 is connected to the collector of the transistor Q2 via the twelfth resistor R2. The eleventh resistor R1 is connected between the source and gate of the MOSFET Q1.

[0044] The working principle of this embodiment is explained below:

[0045] 1) Working principle of emitter follower circuit 41:

[0046] ① Because the AC / DC feedback voltage is different from the DC / DC feedback voltage, resistors R12 and R4 are added to make the feedback voltage Vac-fb and Vdc-fb approximately the same (in existing technologies, resistors R12 and R4 are not used; instead, R9 and R13 directly sample the AC / DC output voltage for feedback, and R3 and R5 directly sample the DC / DC output voltage for feedback). Currently, Vac-fb is designed to be slightly lower than Vdc-fb to ensure a low DC / DC output voltage during shoot-through, preventing the DC / DC feedback from being too low and keeping it in 100% operating mode. A differential amplifier circuit composed of op-amp IC1A, R7, R8, R10, and R11 applies the voltage emitter follower from R3 to R9; currently, the differential amplification ratio is 1:1. Since the feedback voltages Vac-fb and Vdc-fb are approximately the same, and the voltages of R3 and R9 are kept consistent due to the emitter follower circuit, when the protocol's constant current source signal is applied to R3, the voltage of R3 changes, and the voltage of R9 also changes accordingly. This achieves synchronous regulation of the DC / DC and AC / DC output voltages by the protocol's constant current source signal.

[0047] The above principle is explained in more detail below. For example, suppose the feedback value set for the DC / DC converter is Vref1, and the feedback value set for the AC / DC converter is Vref2, where Vref1 ≠ Vref2. Then we need to design R12 and R4 to satisfy the following conditions:

[0048]

[0049] This ensures that the feedback voltage Vac-fb is approximately the same as Vdc-fb.

[0050] Assuming Vac-fb and Vdc-fb are exactly equal, the voltage at one end of the connection between R10 and R11 is V1, the AC / DC output is Vac, and the DC / DC output is Vdc:

[0051] According to the voltage divider principle based on series resistors:

[0052]

[0053] Based on the virtual short and virtual open characteristics of the op-amp, the voltage across the connection of R10 and R11 is equal to the voltage across the connection of R7 and R8, both equal to V1. Therefore, the following formula can be obtained:

[0054]

[0055] Combining the above two calculation formulas (2) and (3), assuming R8 = R10 and R7 = R11, we can finally obtain:

[0056]

[0057] If R7 = R8, then the voltage across the two ends of resistor R9 (V) can be observed. ac -V ac-fb The voltage across the two terminals of resistor R3 (V) dc -V dc-fb ).

[0058] ② The transistor Q2 added to the differential amplifier circuit utilizes the PN junction characteristic of its base and emitter, allowing current to flow inwards but not outwards. This means that the voltage across R3 is only increased when the voltage across R9 is greater than its initial voltage. If the voltage across R3 is less than R9's initial voltage, Q2 disconnects, R9's voltage returns to its initial value and remains constant, and the op-amp output remains high. This ensures that the initial AC / DC output voltage is higher than the initial DC / DC output voltage. For example, if the AC / DC output voltage range is 13.5V-20V and the DC / DC output voltage is 5V-20V, when the DC / DC voltage is below 13.5V, the AC / DC output is 13.5V; when the DC / DC voltage is above 13.5V, the AC / DC output voltage adjusts to match the DC / DC output voltage.

[0059] 2) Working principle of the through circuit 3:

[0060] ① When the voltage of R3 is greater than the initial voltage of R9, the voltage at the inverting input terminal of op-amp IC1A is too high, and the voltage at the output terminal of op-amp IC1A is adjusted down. Through the base-emitter junction of Q2, R9 and R3 are made equal. At this time, the emitter voltage of Q2 is lower than the base voltage and will reach the turn-on voltage, so Q2 turns on. When Q2 turns on, the direct-pass MOS Q1 will also turn on.

[0061] ② When the voltage of R3 is less than the initial voltage of R9, the voltage of the inverting input terminal of op-amp IC1A is too low. Due to the PN junction characteristics of the base-emitter junction of Q2, the feedback signal cannot be raised, resulting in the op-amp output terminal always being high. This causes the emitter voltage of Q2 to be higher than the base voltage, so Q2 is turned off. When Q2 is turned off, the direct-acting MOS Q1 will also be turned off.

[0062] As can be seen, the open-loop protocol in this embodiment uses a voltage-regulating constant current source signal to regulate the DC / DC voltage, and then reads the voltage change of the DC / DC feedback resistor to regulate the voltage of the AC / DC feedback resistor, so that the voltage-regulating constant current source signal indirectly regulates the AC / DC voltage; moreover, when the DC / DC output demand voltage is increased and is higher than the AC / DC initial voltage, the AC / DC will simultaneously turn on the shoot-through while adjusting synchronously with the DC / DC; when the DC / DC output demand voltage is lower than the AC / DC initial voltage, the AC / DC will maintain the initial voltage while simultaneously turning off the shoot-through.

[0063] It should be noted that, Figure 1 The image only shows one DC / DC converter, but multiple DC / DC converters can actually be used in combination. When there are multiple DC / DC converters, if two or more DC / DC converters are simultaneously driven, the PN junction characteristics of the base and emitter of Q2 cause the AC / DC output voltage to follow the output voltage demand of the highest-power DC / DC converter. Since the output voltage demand of each DC / DC converter differs during the shoot-through process, it is possible to control only the DC / DC converter with the highest power to enable the voltage follower function through software, while preventing the other DC / DC converters from entering the voltage follower function and allowing them to operate in the traditional step-down mode.

[0064] The output voltage requirement mentioned in this article refers to the voltage at the first terminal of resistor R3 in DC / DC circuit 2, or the voltage required by the protocol.

[0065] It should be noted that the initial voltage of AC / DC circuit 1 refers to the output voltage of AC / DC circuit 1 when the voltage follower and direct-through extraction circuit 4 is not involved in voltage regulation. Specifically, when the output of the voltage follower and direct-through extraction circuit 4 does not affect the feedback of AC / DC circuit 1, but the bias current generated on the input and output feedback sampling of the voltage follower and direct-through extraction circuit 4 affects the feedback of AC / DC circuit 1, the output of AC / DC circuit 1 when the feedback voltage of the feedback resistor reaches the set feedback value is the initial voltage described in this invention. In fact, the initial voltage of AC / DC circuit 1 is... Figure 2 When Q2 is disconnected, the AC / DC chip output voltage reaches the feedback value at the feedback pin.

[0066] Based on the same inventive concept, this invention also claims protection for a PD power supply, including a battery, a microcontroller, and a constant current source voltage regulation power supply circuit as described in the above embodiments, wherein the microcontroller is communicatively connected to AC / DC and DC / DC chips respectively. It may also include conventional circuits such as battery temperature detection, indicator lights, and touch control, all connected to the microcontroller.

[0067] Based on the same inventive concept, this invention also discloses a constant current source voltage-regulating power supply control method, implemented based on the aforementioned constant current source voltage-regulating power supply circuit, the method comprising:

[0068] DC / DC circuit 2 receives the voltage-regulating constant current source signal and applies it to the voltage change of the feedback resistor to adjust its own output voltage;

[0069] When the output demand voltage of the DC / DC circuit 2 is not lower than the initial voltage of the AC / DC circuit 1, the voltage follower and direct extraction circuit 4 opens the direct circuit 3 and reads the voltage change of the feedback resistor of the DC / DC circuit 2 under the action of the voltage-regulating constant current source signal to adjust the voltage of the feedback resistor of the AC / DC circuit 1, so that the voltage-regulating constant current signal indirectly adjusts the output voltage of the AC / DC circuit 1 to follow the output demand voltage of the DC / DC circuit 2.

[0070] When the output demand voltage of the DC / DC circuit 2 is lower than the initial voltage of the AC / DC circuit 1, the voltage follower and direct extraction circuit 4 shuts off the direct circuit 3 and disconnects the following effect on the output demand voltage of the DC / DC circuit 2, so that the output voltage of the AC / DC circuit 1 maintains the initial voltage.

[0071] For more details, please refer to the section on constant current source power supply control circuits; these details will not be elaborated upon here.

[0072] In summary, the constant current source voltage regulation power supply circuit, method, and PD power supply of the present invention have the following beneficial effects: This application adjusts the voltage of the feedback resistor of the AC / DC circuit by reading the voltage change of the feedback resistor of the DC / DC circuit under the action of the voltage regulation constant current source signal, so that the voltage regulation constant current source signal indirectly regulates the output voltage of the AC / DC circuit, thereby realizing the synchronous regulation of the output voltage of the DC / DC circuit and the AC / DC circuit by the voltage regulation constant current source signal; when the output demand voltage of the DC / DC circuit is lower than the initial voltage of the AC / DC circuit, that is, when the DC / DC circuit steps down, the DC / DC circuit is turned off. The circuit is opened while the voltage follower function is closed to maintain the output voltage of the AC / DC circuit at the initial voltage. In this case, it is equivalent to relying on the DC / DC circuit for step-down output. When the output voltage required by the DC / DC circuit is not lower than the initial voltage of the AC / DC circuit, the pass-through circuit is opened and the voltage follower function is opened at the same time, so that the voltage-regulating constant current source signal indirectly regulates the output voltage of the AC / DC circuit. That is, the voltage followed by the AC / DC circuit is directly passed through for output. In this way, DC / DC pass-through and AC / DC synchronous voltage regulation are realized when the high voltage level output is under the open-loop protocol, thereby improving the overall efficiency.

[0073] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0074] It should be noted that the term "connected" or "linked" not only includes directly connecting two entities, but also includes indirectly connecting them through other entities that have a beneficial improvement effect.

[0075] The terms "first," "second," and other ordinal numbers used in this specification are used to describe various constituent elements, but these constituent elements are not limited by these terms. The purpose of using these terms is solely to distinguish one constituent element from others. For example, without departing from the scope of the invention, a first constituent element may be named a second constituent element, and similarly, a second constituent element may be named a first constituent element.

[0076] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims. All of these forms are within the protection scope of the present invention.

Claims

1. A constant current source voltage regulating power supply circuit comprising an AC / DC circuit (1) and at least one DC / DC circuit (2) connected to the rear stage of said AC / DC circuit (1), said DC / DC circuit (2) being arranged to receive a voltage regulating constant current source signal and to act on the voltage variation of a feedback resistor to regulate its own output voltage, characterized in that, The constant-current source voltage regulating power supply circuit further comprises, for each of the DC / DC circuits (2): a pass-through circuit (3) connected in parallel with the corresponding DC / DC circuit (2), for outputting the output voltage of the AC / DC circuit (1) when the pass-through circuit (3) is opened; a voltage follower and pass-through extraction circuit (4) connected between the output feedback side of the AC / DC circuit (1) and the output feedback side of the DC / DC circuit (2) and also connected to the controlled end of the pass-through circuit (3), for opening the pass-through circuit (3) when the output demand voltage of the DC / DC circuit (2) is not lower than the initial voltage of the AC / DC circuit (1), and adjusting the voltage of the feedback resistor of the AC / DC circuit (1) by reading the voltage change of the feedback resistor of the DC / DC circuit (2) under the action of the constant-current source voltage regulating signal, so that the constant-current source voltage regulating signal indirectly adjusts the output voltage of the AC / DC circuit (1) to follow the output demand voltage of the DC / DC circuit (2); and for closing the pass-through circuit (3) when the output demand voltage of the DC / DC circuit (2) is lower than the initial voltage of the AC / DC circuit (1), and breaking the following action on the output demand voltage of the DC / DC circuit (2), so that the output voltage of the AC / DC circuit (1) is maintained at the initial voltage; The voltage follower and pass-through extraction circuit (4) comprises: a voltage follower circuit (41) connected between the output feedback side of the AC / DC circuit (1) and the output feedback side of the DC / DC circuit (2), for following the voltage change of the feedback resistor of the DC / DC circuit (2) and acting on the feedback resistor of the AC / DC circuit (1) to make the output voltage of the AC / DC circuit (1) follow the output demand voltage of the DC / DC circuit (2); a unidirectional switch circuit (42) arranged in the output path of the voltage follower circuit (41) and connected to the controlled end of the pass-through circuit (3), for closing the pass-through circuit (3) and breaking the voltage follower circuit (41) when the output demand voltage of the DC / DC circuit (2) is lower than the initial voltage of the AC / DC circuit (1), so that the output voltage of the AC / DC circuit (1) is maintained at the initial voltage, and for opening the pass-through circuit (3) and the voltage follower circuit (41) when the output demand voltage of the DC / DC circuit (2) is not lower than the initial voltage of the AC / DC circuit (1).

2. The constant-current source voltage regulating power supply circuit according to claim 1, characterized in that, The DC / DC circuit (2) comprises a DC / DC chip, a first resistor (R3), a second resistor (R4), and a third resistor (R5), a first end of the first resistor (R3) is connected to a voltage output pin of the DC / DC chip, a second end of the first resistor (R3) is connected to a first end of the second resistor (R4) and receives the voltage-regulating constant-current source signal, a second end of the second resistor (R4) and a first end of the third resistor (R5) are connected to a feedback pin of the DC / DC chip, and a second end of the third resistor (R5) is connected to a direct-current output ground (AGND). The AC / DC circuit (1) comprises an AC / DC chip, a fourth resistor (R9), a fifth resistor (R12), and a sixth resistor (R13), a first end of the fourth resistor (R9) is connected to a voltage output pin of the AC / DC chip, a second end of the fourth resistor (R9) is connected to a first end of the fifth resistor (R12), a second end of the fifth resistor (R12) and a first end of the sixth resistor (R13) are connected to a feedback pin of the AC / DC chip, and a second end of the sixth resistor (R13) is connected to a direct-current output ground (AGND). The resistance values of the second resistor (R4), the third resistor (R5), the fifth resistor (R12), and the sixth resistor (R13) satisfy: when the feedback pins of the AC / DC chip and the DC / DC chip reach the respective set feedback values, the difference between the voltage (Vdc-fb) at the first end of the second resistor (R4) and the voltage (Vac-fb) at the first end of the fifth resistor (R12) is a preset deviation voltage. The shoot-through circuit (41) is a differential amplification circuit, the differential inputs of the shoot-through circuit (41) are respectively connected to the second end and the first end of the first resistor (R3), and the differential outputs are respectively connected to the first end and the second end of the fourth resistor (R9), so as to shoot the voltage at the two ends of the first resistor (R3) to the voltage at the two ends of the fourth resistor (R9).

3. The constant current source regulated power supply circuit of claim 2, wherein, The preset deviation voltage is 0.2V.

4. The constant current source regulated power supply circuit of claim 2, wherein, The shoot-through circuit (41) comprises an operational amplifier (IC1A), a seventh resistor (R7), an eighth resistor (R8), a ninth resistor (R10), and a tenth resistor (R11), the inverting input end of the operational amplifier (IC1A) is connected to the first end of the first resistor (R3) through the eighth resistor (R8), the inverting input end of the operational amplifier (IC1A) is also connected to the second end of the fourth resistor (R9) through the seventh resistor (R7), the non-inverting input end of the operational amplifier (IC1A) is connected to the second end of the first resistor (R3) through the ninth resistor (R10), the non-inverting input end of the operational amplifier (IC1A) is also connected to the first end of the fourth resistor (R9) through the tenth resistor (R11), and the unidirectional switching circuit (42) is connected between the second end of the fourth resistor (R9) and the output end of the operational amplifier (IC1A).

5. The constant current source regulated power supply circuit of claim 4, wherein, The one-way switch circuit (42) comprises an NPN type transistor (Q2), the base of the transistor (Q2) is connected to the second end of the fourth resistor (R9), the emitter of the transistor (Q2) is connected to the output of the operational amplifier (IC1A), and the collector of the transistor (Q2) is connected to the pass-through circuit (3).

6. The constant current source regulated power supply circuit of claim 5, wherein, The pass-through circuit (3) comprises a MOS transistor (Q1), an eleventh resistor (R1) and a twelfth resistor (R2), the MOS transistor (Q1) is connected between the voltage output pin of the AC / DC chip and the voltage output pin of the DC / DC chip, the gate of the MOS transistor (Q1) is connected to the collector of the transistor (Q2) via the twelfth resistor (R2), and the eleventh resistor (R1) is connected between the source and the gate of the MOS transistor (Q1).

7. A PD power supply characterized by, The constant current source voltage regulating power supply circuit comprises the constant current source voltage regulating power supply circuit according to any one of claims 1-6.

8. A constant current source voltage regulating power supply control method, characterized by, The method is realized based on the constant current source voltage regulating power supply circuit according to any one of claims 1-6, and the method comprises: The DC / DC circuit (2) receives the voltage regulating constant current source signal and acts on the voltage change of the feedback resistor to regulate the output voltage of the DC / DC circuit (2) itself; When the output demand voltage of the DC / DC circuit (2) is not lower than the initial voltage of the AC / DC circuit (1), the voltage following and pass-through extraction circuit (4) opens the pass-through circuit (3), reads the voltage change of the feedback resistor of the DC / DC circuit (2) caused by the voltage regulating constant current source signal, and regulates the voltage of the feedback resistor of the AC / DC circuit (1), so that the voltage regulating constant current signal indirectly regulates the output voltage of the AC / DC circuit (1) to follow the output demand voltage of the DC / DC circuit (2); When the output demand voltage of the DC / DC circuit (2) is lower than the initial voltage of the AC / DC circuit (1), the voltage following and pass-through extraction circuit (4) closes the pass-through circuit (3), and disconnects the following action on the output demand voltage of the DC / DC circuit (2), so that the output voltage of the AC / DC circuit (1) maintains the initial voltage. The constant current source voltage regulating power supply circuit comprises the constant current source voltage regulating power supply circuit according to any one of claims 1-6.

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