Output-controllable DC-DC conversion device and control method thereof

Abstract

Disclosed in the present invention are an output-controllable DC-DC conversion device and a control method thereof. The device comprises a voltage regulator circuit, an output feedback circuit, a control circuit, a previous-stage bias amplifier circuit, a sampling circuit, and a subsequent-stage bias amplifier circuit. An input end of the voltage regulator circuit is electrically connected to an input power supply; an output end of the voltage regulator circuit is electrically connected to an input end of the sampling circuit by means of the output feedback circuit; an output end of the sampling circuit is electrically connected to an input end of the control circuit and an input end of the subsequent-stage bias amplifier circuit, respectively; an output end of the control circuit is electrically connected to the input end of the subsequent-stage bias amplifier circuit by means of the previous-stage bias amplifier circuit; an output end of the subsequent-stage bias amplifier circuit is electrically connected to the input end of the voltage regulator circuit. The present invention realizes the bidirectional feedback adjustment in real time of an output voltage of the voltage regulator circuit, and achieves controllable output changes, the device is not limited to a preset fixed output value and can adapt to more use environments, and the universality is high.

Description

DC-DC conversion device with controllable output and control method thereof Technical Field

[0001] The present invention relates to the field of electronic devices, and in particular to a DC-DC conversion device with controllable output and a control method thereof. Background Art

[0002] With advancements in electronics technology, electronic products have become essential tools in people's lives. To enable these products to provide diverse functions, it's become inevitable to supply multiple power sources to their application circuits. Among these, using DC-DC converters to generate the required power is a common method.

[0003] In conventional technology, a DC-DC conversion device as shown in FIG1 is generally used, which includes a voltage stabilizing circuit and an output feedback circuit. The output end of the voltage stabilizing circuit is electrically connected to the input end of the output feedback circuit, and the output end of the output feedback circuit is electrically connected to the input end of the voltage stabilizing circuit, that is, the output feedback circuit is directly connected to the voltage stabilizing circuit. The output feedback circuit collects the output voltage of the voltage stabilizing circuit, obtains a feedback voltage and feeds it back to the voltage stabilizing circuit. Based on the feedback regulation function of the voltage stabilizing circuit itself, the output voltage is adjusted according to the feedback voltage, so that the output voltage is stabilized at a preset fixed value.

[0004] However, in the aforementioned conventional DC-DC converter, since the feedback voltage is fed back directly to the voltage regulator circuit via the output feedback circuit, the feedback voltage received by the voltage regulator circuit depends on the sampling function of the output feedback circuit. When the entire DC-DC converter is shipped from the factory, the feedback regulation function of the voltage regulator circuit itself and the sampling function of the output feedback circuit are already designed. Therefore, based on the determined feedback regulation function and sampling function, the output voltage VOUT that the conventional DC-DC converter can output and regulate is fixed. Therefore, conventional DC-DC converters cannot output a controllably variable voltage, which makes the DC-DC converter unsuitable for a wide range of use environments and has poor versatility.

[0005] Summary of the Invention

[0006] In view of this, the present invention provides a DC-DC converter device with controllable output and a control method thereof to solve the problem that existing DC-DC converter devices cannot achieve controllable output changes and have poor versatility.

[0007] The present invention provides a DC-DC conversion device with controllable output, the device comprising a voltage stabilizing circuit and an output feedback circuit, and further comprising a control circuit, a front-stage bias amplifier circuit, a sampling circuit and a rear-stage bias amplifier circuit;

[0008] The input end of the voltage stabilizing circuit is electrically connected to an input power supply, the output end of the voltage stabilizing circuit is electrically connected to the input end of the sampling circuit via the output feedback circuit, the output end of the sampling circuit is electrically connected to the input end of the control circuit and the input end of the post-stage bias amplifier circuit respectively, the output end of the control circuit is electrically connected to the input end of the post-stage bias amplifier circuit via the pre-stage bias amplifier circuit, and the output end of the post-stage bias amplifier circuit is electrically connected to the input end of the voltage stabilizing circuit;

[0009] The voltage stabilizing circuit is used to perform voltage stabilization conversion on the input voltage output by the input power supply to obtain an original output voltage;

[0010] The output feedback circuit is used to obtain the original output voltage and obtain an original feedback voltage according to the original output voltage;

[0011] The sampling circuit is used to collect the original feedback voltage to obtain a sampled voltage, and send the sampled voltage to the control circuit and the post-stage bias amplifier circuit respectively;

[0012] The control circuit is used to generate a pre-stage bias control signal according to the sampled voltage, and send the pre-stage bias control signal to the pre-stage bias amplifier circuit;

[0013] The front-stage bias amplifier circuit is used to amplify according to the front-stage bias control signal to obtain a front-stage bias voltage, and send the front-stage bias voltage to the rear-stage bias amplifier circuit;

[0014] The post-stage bias amplifier circuit is used to amplify the sampling voltage and the pre-stage bias voltage to obtain a target feedback voltage, and send the target feedback voltage to the voltage stabilization circuit;

[0015] The voltage stabilizing circuit is further configured to adjust the original output voltage according to the target feedback voltage to obtain a target output voltage.

[0016] Optionally, the pre-stage bias amplifier circuit includes a first operational amplifier, a first resistor, a second resistor, a third resistor, a fourth resistor and a fifth resistor;

[0017] The positive power input pin of the first op amp is electrically connected to the +5V power supply terminal, the negative power input pin of the first op amp is electrically connected to the -5V power supply terminal, the non-inverting input pin of the first op amp is electrically connected to the output terminal of the control circuit through the first resistor, and the non-inverting input pin of the first op amp is also electrically connected to the reference power supply terminal through the second resistor; the inverting input pin of the first op amp is grounded through the fourth resistor, the first end of the third resistor is connected to the common connection terminal between the non-inverting input pin of the first op amp and the first resistor, and the second end of the third resistor is grounded; the inverting input pin of the first op amp is also electrically connected to the output pin of the first op amp through the fifth resistor, and the output pin of the first op amp is also electrically connected to the input terminal of the post-stage bias amplifier circuit.

[0018] Optionally, the sampling circuit includes a sixth resistor, a seventh resistor, an eighth resistor and a first capacitor;

[0019] A first end of the eighth resistor is electrically connected to the output end of the output feedback circuit, a second end of the eighth resistor is electrically connected to the input end of the control circuit, and the first end of the eighth resistor is also electrically connected to the input end of the post-stage bias amplifier circuit via the sixth resistor. A first end of the first capacitor is connected to a common connection end between the second end of the eighth resistor and the input end of the control circuit, a second end of the first capacitor is grounded, and a second end of the first capacitor is also electrically connected to the input end of the post-stage bias amplifier circuit via the seventh resistor.

[0020] Optionally, the post-stage bias amplifier circuit includes a second operational amplifier, a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor, a second capacitor, and a third capacitor;

[0021] The power input pin of the second operational amplifier is electrically connected to the circuit power supply terminal VCC, and the ground pin of the second operational amplifier is grounded; the non-inverting input pin of the second operational amplifier is electrically connected to the output terminal of the pre-stage bias amplifier circuit through the ninth resistor, and the non-inverting input pin of the second operational amplifier is also grounded through the tenth resistor; the first end of the second capacitor is connected to the common connection terminal between the ninth resistor and the output terminal of the pre-stage bias amplifier circuit, the second end of the second capacitor is grounded, and the non-inverting input pin of the second operational amplifier is also electrically connected to the first end of the sixth resistor; the inverting input pin of the second operational amplifier is electrically connected to the first end of the seventh resistor, and the inverting input pin of the second operational amplifier is also electrically connected to the output pin of the second operational amplifier through the eleventh resistor, and the output pin of the second operational amplifier is electrically connected to the input terminal of the voltage stabilizing circuit through the twelfth resistor; the first end of the third capacitor is connected to the common connection terminal between the twelfth resistor and the input terminal of the voltage stabilizing circuit, and the second end of the third capacitor is grounded.

[0022] Optionally, the voltage stabilizing circuit includes a voltage stabilizing chip, a thirteenth resistor, a fourth capacitor, a fifth capacitor, a sixth capacitor, a seventh capacitor, an eighth capacitor, a ninth capacitor, an inductor and a diode;

[0023] The power input pin VIN and the enable pin EN of the voltage stabilizing chip are both electrically connected to the input power supply, the first end of the fourth capacitor and the first end of the fifth capacitor are both connected to the common connection end between the power input pin VIN of the voltage stabilizing chip and the input power supply, the second end of the fourth capacitor and the second end of the fifth capacitor are both grounded; the multi-function control pin RT / SYNC of the voltage stabilizing chip is grounded through the thirteenth resistor; the ground pin GND and the ground potential pin EPAD of the voltage stabilizing chip are both grounded, the sampling pin SS of the voltage stabilizing chip is grounded through the seventh capacitor, and the input feedback pin FB of the voltage stabilizing chip is connected to the post-stage The output end of the bias amplifier circuit is electrically connected; the switch pin BOOT of the voltage stabilizing chip is electrically connected to the output pin SW of the voltage stabilizing chip through the sixth capacitor, and the output pin SW of the voltage stabilizing chip is also electrically connected to the input end of the output feedback circuit and the external device through the inductor, the cathode of the diode is connected to the common connection end between the output pin of the voltage stabilizing chip and the inductor, the anode of the diode is grounded, the first end of the eighth capacitor and the first end of the ninth capacitor are both connected to the common connection end between the inductor and the input end of the output feedback circuit, and the second end of the eighth capacitor and the second end of the ninth capacitor are both grounded.

[0024] Optionally, the output feedback circuit includes a fourteenth resistor and a fifteenth resistor;

[0025] A first end of the fourteenth resistor is connected to a common connection end between the inductor and the external device, a second end of the fourteenth resistor is grounded through the fifteenth resistor, and an input end of the sampling circuit is connected to a common connection end between the second end of the fourteenth resistor and the fifteenth resistor.

[0026] Optionally, the device further comprises a follower circuit;

[0027] The input end of the follower circuit is electrically connected to the output end of the output feedback circuit, and the output end of the follower circuit is electrically connected to the input end of the sampling circuit;

[0028] The follower circuit is configured to send the original feedback voltage output by the output feedback circuit to the sampling circuit and prevent the target feedback voltage in the post-stage bias amplifier circuit from returning to the output feedback circuit through the sampling circuit.

[0029] Optionally, the follower circuit includes a third operational amplifier;

[0030] The power input pin of the third op amp is electrically connected to the circuit power supply terminal VCC, the ground pin of the third op amp is grounded, the non-inverting input pin of the third op amp is electrically connected to the output terminal of the output feedback circuit, the inverting input pin of the third op amp is electrically connected to the output pin of the third op amp, and the output pin of the third op amp is also electrically connected to the input terminal of the sampling circuit.

[0031] Optionally, the control circuit includes a single chip microcomputer having an analog-to-digital conversion pin and a digital-to-analog conversion pin;

[0032] The output end of the sampling circuit is electrically connected to the analog-to-digital conversion pin of the single-chip microcomputer, and the digital-to-analog conversion pin of the single-chip microcomputer is electrically connected to the input end of the pre-stage bias amplifier circuit;

[0033] The single-chip microcomputer is used to access the sampled voltage collected by the sampling circuit through the analog-to-digital conversion pin, and perform analog-to-digital conversion on the sampled voltage to obtain a digital voltage signal; it is also used to generate a digital control signal based on the digital voltage signal, and perform digital-to-analog conversion on the digital control signal through the digital-to-analog conversion pin to obtain the analog pre-stage bias control signal, and send it to the pre-stage bias amplifier circuit.

[0034] In addition, the present invention also provides a control method for a DC-DC converter device with controllable output, wherein the control method is configured to output a target output voltage using the aforementioned DC-DC converter device with controllable output. The method comprises:

[0035] The voltage stabilizing circuit is used to perform voltage stabilization conversion on the input voltage output by the input power supply to obtain the original output voltage;

[0036] Obtaining the original output voltage by using an output feedback circuit, and obtaining an original feedback voltage according to the original output voltage;

[0037] Using a sampling circuit, collecting the original feedback voltage to obtain a sampled voltage;

[0038] Using a control circuit to generate a front-stage bias control signal according to the sampled voltage, and using a front-stage bias amplifier circuit to amplify the front-stage bias control signal to obtain a front-stage bias voltage;

[0039] Using a post-stage bias amplifier circuit, the sampling voltage and the pre-stage bias voltage are respectively obtained, and amplified according to the sampling voltage and the pre-stage bias voltage to obtain a target feedback voltage;

[0040] The voltage stabilizing circuit is used to adjust the original output voltage according to the target feedback voltage to obtain the target output voltage.

[0041] The beneficial effects of the present invention are as follows: a sampling circuit, a control circuit, a pre-stage bias amplifier circuit and a post-stage bias amplifier circuit are respectively added between the output end of the output feedback circuit and the input end of the voltage stabilizing circuit; the sampling circuit is used to collect the original feedback voltage output by the output feedback circuit, and the sampled voltage is obtained and sent to the control circuit, so as to form a feedback closed loop and realize feedback monitoring of the output voltage of the voltage stabilizing circuit; the control circuit generates a pre-stage bias control signal according to the received sampled voltage, and the pre-stage bias control signal can control the amplification of the post-stage pre-stage bias amplifier circuit; since the pre-stage bias control signal is output by the control circuit and is an analog signal, the pre-stage bias voltage that can be positive or negative can be obtained by amplification of the pre-stage bias amplifier circuit. The negative pre-stage bias voltage can be used as a reference voltage for controlling and adjusting the sampling voltage, facilitating the subsequent controllable bidirectional adjustment of the output voltage. The sampling voltage collected by the sampling circuit and the pre-stage bias voltage obtained by the pre-stage bias amplifier circuit are both sent to the post-stage bias amplifier circuit, which amplifies the sampling voltage and the pre-stage bias voltage. Using the pre-stage bias voltage as a reference, a target feedback voltage can be obtained to control the voltage regulator circuit to bidirectionally adjust the voltage output at its output end. The voltage regulator circuit positively or negatively adjusts the original output voltage according to the target feedback voltage, thereby realizing feedback adjustment of the output voltage of the voltage regulator circuit, thereby realizing controllable changes in the output of the entire DC-DC conversion device, rather than being limited to a preset fixed output value.

[0042] The output-controllable DC-DC converter device and control method thereof in the present invention can realize real-time bidirectional feedback regulation of the output voltage of the voltage stabilizing circuit, realize controllable output variation, are not limited to a preset fixed output value, can be applied to a wide range of usage environments, and have strong versatility. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The features and advantages of the present invention will be more clearly understood by referring to the accompanying drawings, which are schematic and should not be construed as limiting the present invention in any way. In the accompanying drawings:

[0044] FIG1 shows a structural diagram of a conventional DC-DC converter;

[0045] FIG2 shows a structural diagram of a DC-DC converter device with controllable output according to a first embodiment of the present invention;

[0046] 3 shows a design diagram of a sampling circuit, a control circuit, a pre-stage bias amplifier circuit, a post-stage bias amplifier circuit, and a follower circuit in a DC-DC converter with controllable output according to a first embodiment of the present invention;

[0047] FIG4 shows a design diagram of a voltage stabilizing circuit and an output feedback circuit in a DC-DC converter device capable of controlling output in a first embodiment of the present invention;

[0048] FIG5 shows a structural diagram of another DC-DC converter device with controllable output according to the first embodiment of the present invention;

[0049] FIG6 shows a flow chart of a control method of a DC-DC converter device with controllable output in a second embodiment of the present invention. DETAILED DESCRIPTION

[0050] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making any creative efforts shall fall within the scope of protection of the present invention.

[0051] Example 1

[0052] As shown in FIG2 , a DC-DC converter device with controllable output includes a voltage stabilization circuit and an output feedback circuit, as well as a control circuit, a pre-stage bias amplifier circuit, a sampling circuit, and a post-stage bias amplifier circuit;

[0053] The input end of the voltage stabilizing circuit is electrically connected to an input power supply, the output end of the voltage stabilizing circuit is electrically connected to the input end of the sampling circuit via the output feedback circuit, the output end of the sampling circuit is electrically connected to the input end of the control circuit and the input end of the post-stage bias amplifier circuit respectively, the output end of the control circuit is electrically connected to the input end of the post-stage bias amplifier circuit via the pre-stage bias amplifier circuit, and the output end of the post-stage bias amplifier circuit is electrically connected to the input end of the voltage stabilizing circuit;

[0054] The voltage stabilizing circuit is used to perform voltage stabilization conversion on the input voltage output by the input power supply to obtain an original output voltage;

[0055] The output feedback circuit is used to obtain the original output voltage and obtain an original feedback voltage according to the original output voltage;

[0056] The sampling circuit is used to collect the original feedback voltage to obtain a sampled voltage, and send the sampled voltage to the control circuit and the post-stage bias amplifier circuit respectively;

[0057] The control circuit is used to generate a pre-stage bias control signal according to the sampled voltage, and send the pre-stage bias control signal to the pre-stage bias amplifier circuit;

[0058] The front-stage bias amplifier circuit is used to amplify according to the front-stage bias control signal to obtain a front-stage bias voltage, and send the front-stage bias voltage to the rear-stage bias amplifier circuit;

[0059] The post-stage bias amplifier circuit is used to amplify the sampling voltage and the pre-stage bias voltage to obtain a target feedback voltage, and send the target feedback voltage to the voltage stabilization circuit;

[0060] The voltage stabilizing circuit is further configured to adjust the original output voltage according to the target feedback voltage to obtain a target output voltage.

[0061] In the conventional DC-DC converter shown in Figure 1, the feedback voltage obtained by the voltage regulator circuit is completely equal to the feedback voltage output by the output feedback circuit. The feedback regulation function of the voltage regulator circuit depends on the feedback regulation function of the voltage regulator circuit itself and the sampling function of the output feedback circuit. The output voltage VOUT that the entire device can output and adjust is fixed (for example, 0.75V). Traditional DC-DC converters can only provide power with uncontrollable output.

[0062] In the DC-DC converter of this embodiment, a sampling circuit, a control circuit, a pre-stage bias amplifier circuit, and a post-stage bias amplifier circuit are respectively added between the output terminal of the output feedback circuit and the input terminal of the voltage stabilization circuit. The sampling circuit collects the original feedback voltage output by the output feedback circuit to obtain a sampled voltage, which is then fed into the control circuit, thereby forming a feedback closed loop to implement feedback monitoring of the output voltage of the voltage stabilization circuit. The control circuit generates a pre-stage bias control signal based on the received sampled voltage. The pre-stage bias control signal can control the amplification of the post-stage pre-stage bias amplifier circuit. Since the pre-stage bias control signal is an analog signal output by the control circuit, a positive or negative pre-stage bias voltage can be obtained by amplification of the pre-stage bias amplifier circuit. The positive or negative pre-stage bias voltage can be used as a reference voltage for controlling and adjusting the sampling voltage, thereby facilitating the subsequent controllable bidirectional adjustment of the output voltage. The sampling voltage collected by the sampling circuit and the pre-stage bias voltage obtained by the pre-stage bias amplifier circuit are both sent to the post-stage bias amplifier circuit, which is amplified based on the sampling voltage and the pre-stage bias voltage. With the pre-stage bias voltage as a reference, a target feedback voltage can be obtained to control the voltage stabilization circuit to bidirectionally adjust the voltage outputted by the output terminal. The voltage stabilization circuit performs positive or negative adjustment on the original output voltage according to the target feedback voltage, thereby realizing feedback adjustment of the output voltage of the voltage stabilization circuit, thereby realizing controllable output variation of the entire DC-DC conversion device, without being limited to a preset fixed output value.

[0063] Compared with conventional DC-DC converters, the output-controllable DC-DC converter of this embodiment does not directly connect the output end of the output feedback circuit to the input end of the voltage stabilization circuit. Instead, a sampling circuit, a control circuit, a pre-stage bias amplifier circuit, and a post-stage bias amplifier circuit are respectively added between the output end of the output feedback circuit and the input end of the voltage stabilization circuit. This enables real-time bidirectional feedback adjustment of the output voltage of the voltage stabilization circuit, achieving controllable output variation. The output is not limited to a preset fixed output value, is applicable to a wide range of usage environments, and has high versatility.

[0064] Preferably, as shown in FIG3 , the pre-stage bias amplifier circuit includes a first operational amplifier U3 , a first resistor R10 , a second resistor R2 , a third resistor R15 , a fourth resistor R8 and a fifth resistor R7 ;

[0065] The positive power input pin of the first op amp U3 is electrically connected to the +5V power supply terminal, the negative power input pin of the first op amp U3 is electrically connected to the -5V power supply terminal, the non-inverting input pin of the first op amp U3 is electrically connected to the output terminal of the control circuit through the first resistor R10, and the non-inverting input pin of the first op amp U3 is also electrically connected to the reference power supply terminal through the second resistor R2; the inverting input pin of the first op amp U3 is grounded through the fourth resistor R8, the first end of the third resistor R15 is connected to the common connection terminal between the non-inverting input pin of the first op amp U3 and the first resistor R10, and the second end of the third resistor R15 is grounded; the inverting input pin of the first op amp U3 is also electrically connected to the output pin of the first op amp U3 through the fifth resistor R7, and the output pin of the first op amp U3 is also electrically connected to the input terminal of the post-stage bias amplifier circuit.

[0066] As shown in FIG3 , in the pre-stage bias amplifier circuit of the above structure, the first op amp receives the pre-stage bias control signal VDA sent by the control circuit through the first resistor R10. Since the signal VDA is an analog signal and can only be positive, the first op amp also receives the reference voltage VBIS provided by the reference power supply terminal through the second resistor R2. By utilizing the setting of the reference voltage VBIS and combining the function of the first op amp, the pre-stage bias control signal VDA, which can only be positive, is amplified into a reference voltage VREF (i.e., the pre-stage bias voltage) that can be either positive or negative. The use of this reference voltage VREF facilitates the subsequent amplification of the post-stage bias amplifier circuit to increase or decrease the sampling voltage, thereby obtaining the target feedback voltage for controlling the bidirectional regulation of the original output voltage.

[0067] In the pre-stage bias amplifier circuit shown in FIG3 , the reference voltage VREF (or pre-stage bias voltage) can be obtained as follows: VREF = (R7 + R8) / R8 * (R2 * R15 * VDA + R10 * R15 * VBIS) / (R2 * R15 + R2 * R10 + R10 * R15);

[0068] When R2*R15*VDA+R10*R15*VBIS>0, VREF>0;

[0069] When R2*R15*VDA+R10*R15*VBIS=0, VREF=0;

[0070] When R2*R15*VDA+R10*R15*VBIS<0, VREF<0 can be obtained.

[0071] Preferably, as shown in FIG3 , the sampling circuit includes a sixth resistor R5 , a seventh resistor R6 , an eighth resistor R9 and a first capacitor C2 ;

[0072] A first end of the eighth resistor R9 is electrically connected to the output end of the output feedback circuit, a second end of the eighth resistor R9 is electrically connected to the input end of the control circuit, and the first end of the eighth resistor R9 is also electrically connected to the input end of the post-stage bias amplifier circuit via the sixth resistor R5. A first end of the first capacitor C2 is connected to a common connection end between the second end of the eighth resistor R9 and the input end of the control circuit, a second end of the first capacitor C2 is grounded, and a second end of the first capacitor C2 is also electrically connected to the input end of the post-stage bias amplifier circuit via the seventh resistor R6.

[0073] Through the sampling circuit of this structure, the original feedback voltage output by the output feedback circuit can be collected and processed into a sampling voltage. On the one hand, it is sent to the control circuit to generate a pre-stage bias control signal to control the pre-stage bias amplifier circuit to amplify the pre-stage bias, so as to obtain a pre-stage bias voltage that can be positive or negative, providing a bidirectionally adjustable reference voltage for the sampling voltage; on the other hand, it is sent to the post-stage bias amplifier circuit as a data source for generating the target feedback voltage, ensuring the generation of the target feedback voltage.

[0074] Preferably, as shown in FIG3 , the control circuit includes a single chip microcomputer having an analog-to-digital conversion pin and a digital-to-analog conversion pin;

[0075] The output end of the sampling circuit is electrically connected to the analog-to-digital conversion pin of the single-chip microcomputer, and the digital-to-analog conversion pin of the single-chip microcomputer is electrically connected to the input end of the pre-stage bias amplifier circuit;

[0076] The single-chip microcomputer is used to access the sampled voltage collected by the sampling circuit through the analog-to-digital conversion pin, and perform analog-to-digital conversion on the sampled voltage to obtain a digital voltage signal; it is also used to generate a digital control signal based on the digital voltage signal, and perform digital-to-analog conversion on the digital control signal through the digital-to-analog conversion pin to obtain the analog pre-stage bias control signal, and send it to the pre-stage bias amplifier circuit.

[0077] The above-mentioned single-chip microcomputer facilitates receiving the analog sampling voltage and digitizing it, so that the single-chip microcomputer can analyze and generate a digital control signal. At the same time, it is also convenient to convert the digital control signal into the analog pre-stage bias control signal required by the pre-stage bias amplifier circuit connected to the single-chip microcomputer, thereby realizing the single-chip microcomputer's control over the pre-stage bias amplifier circuit.

[0078] As shown in Figure 3, the analog-to-digital conversion pin of the single-chip microcomputer is the A / D pin, and the digital-to-analog conversion pin is the D / A pin. The first end of the eighth resistor R9 in the sampling circuit is electrically connected to the output end of the output feedback circuit. The original feedback voltage output by the output end of the output feedback circuit is VOFB. The original feedback voltage VOFB is sampled by the eighth resistor R9. The second end of the eighth resistor R9 obtains the sampling voltage VA / D, which is connected to the A / D pin of the single-chip microcomputer and sent to the single-chip microcomputer; the single-chip microcomputer generates a digital control signal according to the analog-to-digital conversion of the sampling voltage VA / D, and performs digital-to-analog conversion through the D / A pin to generate an analog pre-stage bias control signal VDA, which is sent to the non-inverting input pin of the first operational amplifier U3 through the first resistor R10 in the pre-stage bias amplifier circuit.

[0079] Preferably, as shown in FIG3 , the post-stage bias amplifier circuit includes a second operational amplifier U1 , a ninth resistor R3 , a tenth resistor R4 , an eleventh resistor R1 , a twelfth resistor R11 , a second capacitor C1 and a third capacitor C4 ;

[0080] The power input pin of the second operational amplifier U1 is electrically connected to the circuit power supply terminal VCC, and the ground pin of the second operational amplifier U1 is grounded; the non-inverting input pin of the second operational amplifier U1 is electrically connected to the output terminal of the pre-stage bias amplifier circuit through the ninth resistor R3, and the non-inverting input pin of the second operational amplifier U1 is also grounded through the tenth resistor R4. The first end of the second capacitor C1 is connected to the common connection terminal between the ninth resistor R3 and the output terminal of the pre-stage bias amplifier circuit, and the second end of the second capacitor C1 is grounded. The non-inverting input pin of the second operational amplifier U1 is electrically connected to the output terminal of the pre-stage bias amplifier circuit through the ninth resistor R3. It is also electrically connected to the first end of the sixth resistor R5; the inverting input pin of the second operational amplifier U1 is electrically connected to the first end of the seventh resistor R6, the inverting input pin of the second operational amplifier U1 is also electrically connected to the output pin of the second operational amplifier U1 through the eleventh resistor R1, the output pin of the second operational amplifier U1 is electrically connected to the input end of the voltage stabilizing circuit through the twelfth resistor R11, the first end of the third capacitor C4 is connected to the common connection end between the twelfth resistor R11 and the input end of the voltage stabilizing circuit, and the second end of the third capacitor C4 is grounded.

[0081] In the post-stage bias amplifier circuit of the above structure, the sampling voltage output by the sampling circuit and the pre-stage bias voltage output by the pre-stage bias amplifier circuit are both fed into the signal terminal (including the non-inverting input pin and the inverting input pin) of the second operational amplifier, so that the pre-stage bias voltage provided by the pre-stage bias amplifier circuit is used as a reference to bidirectionally adjust the sampling voltage, thereby generating a target feedback voltage that can achieve bidirectional adjustment of the original output voltage.

[0082] In the post-stage bias amplifier circuit shown in FIG3 , the target feedback voltage VFB_IN is obtained as follows: VFB_IN = (R1+R6) / R6*(R3*R4*VOFB+R4*R5*VREF) / (R3*R4+R3*R5+R5*R4);

[0083] When VREF < 0, VFB_IN < VOFB, that is, the target feedback voltage is smaller than the original feedback voltage. Then, after the voltage regulator circuit receives the target feedback voltage smaller than the original feedback voltage, it can increase its own output in combination with the function of the voltage regulator circuit, that is, increase the original output voltage (specifically VOUT).

[0084] When VREF=0, VFB_IN=VOFB, that is, the target feedback voltage is equal to the original feedback voltage. Then, after receiving the target feedback voltage equal to the original feedback voltage, the voltage stabilizing circuit does not increase or decrease its own output, that is, it does not adjust the original output voltage (specifically VOUT).

[0085] When VREF>0, VFB_IN>VOFB can be obtained, that is, the target feedback voltage is larger than the original feedback voltage. After the voltage stabilizing circuit receives the target feedback voltage that is larger than the original feedback voltage, combined with the function of the voltage stabilizing circuit, its own output can be reduced, that is, the original output voltage (specifically VOUT) can be reduced.

[0086] Preferably, as shown in FIG4 , the voltage stabilizing circuit includes a voltage stabilizing chip U2, a thirteenth resistor R13, a fourth capacitor C7, a fifth capacitor C8, a sixth capacitor C6, a seventh capacitor C15, an eighth capacitor C11, a ninth capacitor C12, an inductor L2, and a diode D2;

[0087] The power input pin VIN and the enable pin EN of the voltage stabilizing chip U2 are both electrically connected to the input power supply, the first end of the fourth capacitor C7 and the first end of the fifth capacitor C8 are both connected to the common connection end between the power input pin VIN of the voltage stabilizing chip U2 and the input power supply, the second end of the fourth capacitor C7 and the second end of the fifth capacitor C8 are both grounded; the multi-function control pin RT / SYNC of the voltage stabilizing chip U2 is grounded through the thirteenth resistor R13; the ground pin GND and the ground potential pin EPAD of the voltage stabilizing chip U2 are both grounded, the sampling pin SS of the voltage stabilizing chip U2 is grounded through the seventh capacitor C15, and the input feedback pin FB of the voltage stabilizing chip U2 is connected to the post-stage bias amplifier. The output end of the large circuit is electrically connected; the switch pin BOOT of the voltage stabilizing chip U2 is electrically connected to the output pin SW of the voltage stabilizing chip U2 through the sixth capacitor C6, and the output pin SW of the voltage stabilizing chip U2 is also electrically connected to the input end of the output feedback circuit and the external device through the inductor L2; the cathode of the diode D2 is connected to the common connection end between the output pin of the voltage stabilizing chip U2 and the inductor L2, the anode of the diode D2 is grounded, the first end of the eighth capacitor C11 and the first end of the ninth capacitor C12 are both connected to the common connection end between the inductor L2 and the input end of the output feedback circuit, and the second end of the eighth capacitor C11 and the second end of the ninth capacitor C12 are both grounded.

[0088] The above-mentioned voltage stabilizing circuit can, on the one hand, realize voltage stabilization conversion of the input voltage output by the input power supply to generate the required DC voltage; on the other hand, it can also realize real-time access to the target feedback voltage output by the post-stage bias amplifier circuit according to the input feedback pin FB of the voltage stabilizing chip, and realize bidirectional feedback adjustment of the original output voltage according to the target feedback voltage, thereby realizing controllable change of the output of the entire DC-DC conversion device.

[0089] Preferably, as shown in FIG4 , the output feedback circuit includes a fourteenth resistor R12 and a fifteenth resistor R14 ;

[0090] A first end of the fourteenth resistor R12 is connected to a common connection end between the inductor L2 and the external device, a second end of the fourteenth resistor R12 is grounded through the fifteenth resistor R14, and an input end of the sampling circuit is connected to a common connection end between the second end of the fourteenth resistor R12 and the fifteenth resistor R14.

[0091] The voltage divider circuit composed of the fourteenth resistor R12 and the fifteenth resistor R14 can accurately provide real-time feedback on the original output voltage output by the output pin of the voltage regulator chip.

[0092] For the circuit structure shown in FIG4 , if the voltage stabilizing circuit and the output feedback circuit in the conventional DC-DC converter are designed according to the voltage stabilizing circuit and the output feedback circuit shown in FIG4 , respectively, then in the conventional DC-DC converter, the second end of the fourteenth resistor R12 will be directly connected to the input feedback pin FB of the voltage stabilizing chip U2 , and the output voltage VOUT output by the voltage stabilizing chip will be directly fed back to the input feedback pin of the voltage stabilizing chip U2 through the voltage divider circuit composed of the fourteenth resistor R12 and the fifteenth resistor R14 . Therefore, the feedback voltage VFB_IN obtained by the voltage stabilizing chip is equal to the divided voltage VOFB obtained by the output voltage VOUT through the voltage divider circuit, that is, the feedback voltage VFB_IN depends on the proportional relationship between the fourteenth resistor R12 and the fifteenth resistor R14. Based on the determined fourteenth resistor R12 and fifteenth resistor R14, the output voltage VOUT that can be output and adjusted by the conventional DC-DC converter is fixed. In this embodiment, the circuit structure shown in FIG3 is connected between the voltage stabilizing circuit and the output feedback circuit shown in FIG4 , so that the original output voltage of the voltage stabilizing circuit can be adjusted in a controllable manner and is not limited to a preset fixed value.

[0093] Preferably, as shown in FIG5 , the device further comprises a follower circuit;

[0094] The input end of the follower circuit is electrically connected to the output end of the output feedback circuit, and the output end of the follower circuit is electrically connected to the input end of the sampling circuit;

[0095] The follower circuit is configured to send the original feedback voltage output by the output feedback circuit to the sampling circuit and prevent the target feedback voltage in the post-stage bias amplifier circuit from returning to the output feedback circuit through the sampling circuit.

[0096] A follower circuit is added between the output feedback circuit and the sampling circuit to transmit the original feedback voltage to the sampling circuit through the follower circuit. On the one hand, it facilitates the sampling of the original feedback voltage and improves the output capacity of the output feedback circuit. On the other hand, it also plays an electrical isolation role, preventing the target feedback voltage in the subsequent bias amplifier circuit connected to the sampling circuit from returning to the output feedback circuit through the sampling circuit, affecting the actual sampling of the sampling circuit, and then in the subsequent bias amplifier circuit, when amplification is performed based on the sampling voltage, affecting the accuracy of the target feedback voltage, and ultimately affecting the control accuracy of the output controllable change of the entire DC-DC conversion device.

[0097] Specifically, as shown in FIG3 , the follower circuit includes a third operational amplifier U4;

[0098] The power input pin of the third op amp U4 is electrically connected to the circuit power supply terminal VCC, the ground pin of the third op amp U4 is grounded, the non-inverting input pin of the third op amp U4 is electrically connected to the output terminal of the output feedback circuit, the inverting input pin of the third op amp U4 is electrically connected to the output pin of the third op amp U4, and the output pin of the third op amp U4 is also electrically connected to the input terminal of the sampling circuit.

[0099] Through the follower circuit of the above structure, the voltage in the input direction of the third op amp (i.e., the original feedback voltage) can flow to the sampling circuit of the subsequent stage, while the voltage signal in the subsequent stage bias amplifier circuit (i.e., the target feedback voltage) will not be transmitted to the sampling circuit, thereby accurately limiting the flow direction of the voltage signal, and playing an electrical isolation role while improving the output capacity, without affecting the controllable output of the final target output voltage.

[0100] This embodiment, based on the follower circuit, sampling circuit, control circuit, pre-stage bias amplifier circuit, and post-stage bias amplifier circuit shown in FIG3 , as well as the voltage stabilization circuit and output feedback circuit shown in FIG4 , forms a complete output-controllable DC-DC converter. In this DC-DC converter, by setting the reference voltage VBIS provided by the reference power supply terminal in the pre-stage bias amplifier circuit and then utilizing the VDA output by the single-chip microcomputer, the polarity of the pre-stage bias voltage (or reference voltage) VREF can be controlled (including >0, =0, and <0). Furthermore, the post-stage bias amplifier circuit is used to control VOFB>VFB_IN, VOFB=VFB_IN, or VOFB<VFB_IN, thereby achieving bidirectional regulation of the output voltage of the entire DC-DC converter.

[0101] Preferably, the resistors in the DC-DC converter device shown in FIG3 and FIG4 are designed according to the following relationships: R2=R15=2*R10, R7=R8, R3=R4=2*R5, R6=R1;

[0102] The target output voltage VOUT1 (denoted by VOUT1 to distinguish it from the original output voltage VOUT, indicating that both are output by the voltage regulator circuit, but the specific values ​​may be different) can be obtained as: VOUT1=(R12+R14)*VOFB / R14 =[(R12+R14) / R14]*(VFB_IN-VREF / 2) =[(R12+R14) / R14]*(VFB_IN-VDA / 2–VBIS / 4).

[0103] In this embodiment, since VDA is an analog signal and can only be positive, in order to make the voltage adjustment bidirectional, the reference voltage VBIS is designed as a negative voltage, and the up and down adjustment of VOUT1 can be achieved by adjusting VDA. In order for VOUT1 to output normally, VOUT1 must be ensured to be >0, so it must be ensured that: VDA < 2*(VFB_IN - VBIS / 4);

[0104] Assume that when the maximum value of VDA is 3.3V and VBIS takes -3.3V, at this time:

[0105] When VDA = 1.65V, VREF = 0V, VOFB = VFB_IN, no adjustment;

[0106] When VDA > 1.65V, VREF > 0, VOFB < VFB_IN, VOUT1 becomes smaller;

[0107] When VDA < 1.65V, VREF < 0, VOFB > VFB_IN, VOUT1 becomes larger.

[0108] The calculation formula result of VOUT1 is: VOUT1 = [(R12 + R14) / R14]*(0.75 + 0.825 - VDA / 2) = [(R12 + R14) / R14]*(1.575 - VDA / 2)

[0109] At this time, in order for VOUT1 to output normally, VOUT1 must be ensured to be >0, so VDA can be controlled to be < 3.15V.

[0110] Specifically, in this embodiment, the voltage regulator chip U2 is selected as the LMR14020SDDAR model, the first operational amplifier U3 and the third operational amplifier U4 are both selected as the LM321M5X / TR model, the second operational amplifier U1 is selected as the LM321M5X / TR model or the LM321G-AE5-R model, and the single-chip microcomputer, various resistors, capacitors and other electronic components can be selected according to actual conditions for appropriate specifications or models, which are not listed here.

[0111] Embodiment 2

[0112] As shown in Figure 6, a control method for a DC-DC conversion device with controllable output, using the DC-DC conversion device with controllable output in Embodiment 1 to output a target output voltage, the method includes:

[0113] S1: Using a voltage regulator circuit, performing voltage regulation conversion on the input voltage output by the input power supply to obtain an original output voltage;

[0114] S2: Using an output feedback circuit, obtaining the original output voltage, and obtaining an original feedback voltage according to the original output voltage;

[0115] S3: using a sampling circuit to collect the original feedback voltage to obtain a sampled voltage;

[0116] S4: using a control circuit to generate a front-stage bias control signal according to the sampled voltage, and using a front-stage bias amplifier circuit to amplify the front-stage bias control signal to obtain a front-stage bias voltage;

[0117] S5: using a post-stage bias amplifier circuit to obtain the sampled voltage and the pre-stage bias voltage respectively, and amplify the sampled voltage and the pre-stage bias voltage to obtain a target feedback voltage;

[0118] S6: Utilizing the voltage stabilizing circuit, regulating the original output voltage according to the target feedback voltage to obtain the target output voltage.

[0119] The sampling circuit is used to collect the original feedback voltage output by the output feedback circuit, and the sampled voltage is obtained and sent to the control circuit, so as to form a feedback closed loop and realize feedback monitoring of the output voltage of the voltage stabilizing circuit; the control circuit is used to generate a pre-stage bias control signal according to the received sampled voltage, and the pre-stage bias control signal can control the amplification of the pre-stage bias amplifier circuit of the subsequent stage. Since the pre-stage bias control signal is output by the control circuit and is an analog signal, the amplification of the pre-stage bias amplifier circuit can obtain a positive or negative pre-stage bias voltage, which can be used as a reference voltage for controlling and adjusting the sampled voltage, which is convenient for the subsequent The controllable bidirectional regulation of the output voltage is continuously realized; the sampling voltage collected by the sampling circuit and the pre-stage bias voltage obtained by the pre-stage bias amplifier circuit are both sent to the post-stage bias amplifier circuit, and amplified based on the sampling voltage and the pre-stage bias voltage. The pre-stage bias voltage is used as a reference to obtain a target feedback voltage for controlling the voltage stabilization circuit to perform bidirectional regulation of the voltage output at its output end; the voltage stabilization circuit is used to perform positive or negative regulation on the original output voltage according to the target feedback voltage, thereby realizing feedback regulation of the output voltage of the voltage stabilization circuit, and further realizing controllable output variation of the entire DC-DC conversion device, without being limited to a preset fixed output value.

[0120] The control method of this embodiment can realize real-time bidirectional feedback regulation of the output voltage of the voltage stabilizing circuit, realize controllable output change, is not limited to a preset fixed output value, can be applied to a wide range of usage environments, and has strong versatility.

[0121] The structure of the DC-DC converter with controllable output adopted in the control method described in this embodiment is exactly the same as the structure of the DC-DC converter with controllable output in Example 1. Therefore, for details not fully described in this embodiment, please refer to the specific description of Example 1 and Figures 1 to 5, and will not be repeated here.

[0122] Although the embodiments of the present invention have been described with reference to the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention. Such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A DC-DC conversion device with controllable output, the device comprising a voltage stabilizing circuit and an output feedback circuit, It is characterized in that The device also includes a control circuit, a front-stage bias amplifier circuit, a sampling circuit and a rear-stage bias amplifier circuit; The input end of the voltage stabilizing circuit is electrically connected to the input power supply, the output end of the voltage stabilizing circuit is electrically connected to the input end of the sampling circuit through the output feedback circuit, the output end of the sampling circuit is electrically connected to the input end of the control circuit and the input end of the post-stage bias amplifier circuit respectively, the output end of the control circuit is electrically connected to the input end of the post-stage bias amplifier circuit through the pre-stage bias amplifier circuit, and the output end of the post-stage bias amplifier circuit is electrically connected to the input end of the voltage stabilizing circuit; The voltage stabilizing circuit is used to perform voltage stabilization conversion on the input voltage output by the input power supply to obtain an original output voltage; The output feedback circuit is used to obtain the original output voltage and obtain an original feedback voltage according to the original output voltage; The sampling circuit is used to collect the original feedback voltage to obtain a sampling voltage, and send the sampling voltage to the control circuit and the post-stage bias amplifier circuit respectively; The control circuit is used to generate a front-stage bias control signal according to the sampled voltage, and send the front-stage bias control signal to the front-stage bias amplifier circuit; The front-stage bias amplifier circuit is used to amplify according to the front-stage bias control signal to obtain a front-stage bias voltage, and send the front-stage bias voltage to the rear-stage bias amplifier circuit; The post-stage bias amplifier circuit is used to amplify the sampled voltage and the pre-stage bias voltage to obtain a target feedback voltage, and send the target feedback voltage to the voltage stabilization circuit; The voltage stabilizing circuit is further used to adjust the original output voltage according to the target feedback voltage to obtain a target output voltage.

2. The DC-DC converter with controllable output according to claim 1, It is characterized in that The front-stage bias amplifier circuit includes a first operational amplifier, a first resistor, a second resistor, a third resistor, a fourth resistor and a fifth resistor; The positive power input pin of the first operational amplifier is electrically connected to the +5V power supply terminal. The negative power input pin of the first amplifier is electrically connected to the -5V power supply terminal, the positive input pin of the first amplifier is electrically connected to the output terminal of the control circuit through the first resistor, and the positive input pin of the first amplifier is also electrically connected to the reference power supply terminal through the second resistor; the inverting input pin of the first amplifier is grounded through the fourth resistor, the first end of the third resistor is connected to the common connection terminal between the positive input pin of the first amplifier and the first resistor, and the second end of the third resistor is grounded; the inverting input pin of the first amplifier is also electrically connected to the output pin of the first amplifier through the fifth resistor, and the output pin of the first amplifier is also electrically connected to the input terminal of the post-stage bias amplifier circuit.

3. The DC-DC converter with controllable output according to claim 1, It is characterized in that The sampling circuit includes a sixth resistor, a seventh resistor, an eighth resistor and a first capacitor; The first end of the eighth resistor is electrically connected to the output end of the output feedback circuit, the second end of the eighth resistor is electrically connected to the input end of the control circuit, the first end of the eighth resistor is also electrically connected to the input end of the post-stage bias amplifier circuit through the sixth resistor, the first end of the first capacitor is connected to the common connection end between the second end of the eighth resistor and the input end of the control circuit, the second end of the first capacitor is grounded, and the second end of the first capacitor is also electrically connected to the input end of the post-stage bias amplifier circuit through the seventh resistor.

4. The DC-DC converter with controllable output according to claim 3, It is characterized in that The post-stage bias amplifier circuit includes a second operational amplifier, a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor, a second capacitor and a third capacitor; The power input pin of the second operational amplifier is electrically connected to the circuit power supply terminal VCC, and the ground pin of the second operational amplifier is grounded; the non-inverting input pin of the second operational amplifier is electrically connected to the output terminal of the pre-stage bias amplifier circuit through the ninth resistor, and the non-inverting input pin of the second operational amplifier is also grounded through the tenth resistor, the first end of the second capacitor is connected to the common connection terminal between the ninth resistor and the output terminal of the pre-stage bias amplifier circuit, the second end of the second capacitor is grounded, and the non-inverting input pin of the second operational amplifier is also electrically connected to the first end of the sixth resistor; the inverting input pin of the second operational amplifier is electrically connected to the first end of the seventh resistor, and the inverting input pin of the second operational amplifier is also electrically connected to the output pin of the second operational amplifier through the eleventh resistor, and the output pin of the second operational amplifier is connected to the voltage stabilizing circuit through the twelfth resistor. The first end of the third capacitor is connected to the common connection end between the twelfth resistor and the input end of the voltage stabilizing circuit, and the second end of the third capacitor is grounded.

5. The DC-DC converter with controllable output according to claim 1, It is characterized in that The voltage stabilizing circuit includes a voltage stabilizing chip, a thirteenth resistor, a fourth capacitor, a fifth capacitor, a sixth capacitor, a seventh capacitor, an eighth capacitor, a ninth capacitor, an inductor and a diode; The power input pin VIN and the enable pin EN of the voltage stabilizing chip are both electrically connected to the input power supply, the first end of the fourth capacitor and the first end of the fifth capacitor are both connected to the common connection end between the power input pin VIN of the voltage stabilizing chip and the input power supply, and the second end of the fourth capacitor and the second end of the fifth capacitor are both grounded; the multi-function control pin RT / SYNC of the voltage stabilizing chip is grounded through the thirteenth resistor; the ground pin GND and the ground potential pin EPAD of the voltage stabilizing chip are both grounded, the sampling pin SS of the voltage stabilizing chip is grounded through the seventh capacitor, and the input feedback pin FB of the voltage stabilizing chip is connected to the post-stage The output end of the bias amplifier circuit is electrically connected; the switch pin BOOT of the voltage stabilizing chip is electrically connected to the output pin SW of the voltage stabilizing chip through the sixth capacitor, and the output pin SW of the voltage stabilizing chip is also electrically connected to the input end of the output feedback circuit and the external device through the inductor, the cathode of the diode is connected to the common connection end between the output pin of the voltage stabilizing chip and the inductor, the anode of the diode is grounded, the first end of the eighth capacitor and the first end of the ninth capacitor are both connected to the common connection end between the inductor and the input end of the output feedback circuit, and the second end of the eighth capacitor and the second end of the ninth capacitor are both grounded.

6. The DC-DC converter with controllable output according to claim 5, It is characterized in that The output feedback circuit includes a fourteenth resistor and a fifteenth resistor; The first end of the fourteenth resistor is connected to the common connection end between the inductor and the external device, the second end of the fourteenth resistor is grounded through the fifteenth resistor, and the input end of the sampling circuit is connected to the common connection end between the second end of the fourteenth resistor and the fifteenth resistor.

7. The DC-DC converter with controllable output according to claim 1, It is characterized in that The device also includes a follower circuit; The input end of the follower circuit is electrically connected to the output end of the output feedback circuit. The output end of the circuit is electrically connected to the input end of the sampling circuit; The follower circuit is used to send the original feedback voltage output by the output feedback circuit to the sampling circuit, and prevent the target feedback voltage in the post-stage bias amplifier circuit from returning to the output feedback circuit through the sampling circuit.

8. The DC-DC converter with controllable output according to claim 7, It is characterized in that The follower circuit includes a third operational amplifier; The power input pin of the third op amp is electrically connected to the circuit power supply terminal VCC, the ground pin of the third op amp is grounded, the non-inverting input pin of the third op amp is electrically connected to the output terminal of the output feedback circuit, the inverting input pin of the third op amp is electrically connected to the output pin of the third op amp, and the output pin of the third op amp is also electrically connected to the input terminal of the sampling circuit.

9. The DC-DC converter with controllable output according to any one of claims 1 to 8, It is characterized in that The control circuit includes a single chip microcomputer having an analog-to-digital conversion pin and a digital-to-analog conversion pin; The output end of the sampling circuit is electrically connected to the analog-to-digital conversion pin of the single-chip microcomputer, and the digital-to-analog conversion pin of the single-chip microcomputer is electrically connected to the input end of the pre-stage bias amplifier circuit; The single chip microcomputer is used to access the sampling voltage collected by the sampling circuit through the analog-to-digital conversion pin, and perform analog-to-digital conversion on the sampling voltage to obtain a digital voltage signal; it is also used to generate a digital control signal according to the digital voltage signal, and perform digital-to-analog conversion on the digital control signal through the digital-to-analog conversion pin to obtain the analog pre-stage bias control signal, and send it to the pre-stage bias amplifier circuit.

10. A control method for a DC-DC converter capable of controlling output, It is characterized in that The method of outputting a target output voltage by using the DC-DC converter device with controllable output according to any one of claims 1 to 9 comprises: The voltage stabilization circuit is used to perform voltage stabilization conversion on the input voltage output by the input power supply to obtain the original output voltage; Using an output feedback circuit, the original output voltage is acquired, and an original feedback voltage is obtained according to the original output voltage; Using a sampling circuit to collect the original feedback voltage to obtain a sampled voltage; Using a control circuit to generate a front-stage bias control signal according to the sampled voltage, and using a front-stage bias amplifier circuit to amplify the front-stage bias control signal to obtain a front-stage bias voltage; The sampling voltage and the front-stage bias voltage are respectively obtained by using a rear-stage bias amplifier circuit, and amplified according to the sampling voltage and the front-stage bias voltage to obtain a target feedback voltage; The voltage stabilizing circuit is used to adjust the original output voltage according to the target feedback voltage to obtain the target output voltage.

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