CN102684495A - Digital power supply control circuit, control method and digital power supply using circuit and method - Google Patents

Abstract

The invention relates to a digital power supply control circuit and a control method thereof, which are applied to a digital power supply, and use an analog-to-digital converter to receive the output voltage of the digital power supply, and compare it with n reference values to generate digital error signal, n≥3; then generate a digital duty cycle signal according to the received digital error signal, and transmit the dynamic component to the analog-to-digital converter to adjust the set of reference values; according to the received A DPWM module is used to generate a PWM control signal to control the switching action of the power switch in the digital power supply, so as to ensure that the output voltage of the digital power supply quickly recovers to the desired output voltage.

Description

A digital power supply control circuit, control method and digital power supply using the same

technical field

The invention relates to the field of switching power supplies, in particular to a novel digital power supply control circuit, a control method and a digital power supply using the same.

Background technique

Switching power supply is a kind of power supply that uses modern power electronic technology to control the time ratio of switching on and off to maintain a stable output voltage. Switching power supply is generally composed of pulse width modulation (PWM) control IC and power switch (MOSFET). Existing implementation methods of switching power supplies include analog control methods, digital control methods, and analog-digital hybrid control methods. The switching power supply adopts analog control technology, the output feedback voltage passes through the error amplifier to generate an error signal, and after PID correction and compensation, it is compared with the triangular wave oscillation signal to generate a PWM driving signal. In such an implementation method, the control circuit is complicated, the number of components is large, and it is difficult to modify the control circuit after it is formed, which is not conducive to the integration and miniaturization of the switching power supply. In recent years, due to the advantages of programmability, design continuity, and small number of components, digital control methods have been more and more widely used and recognized.

Using digital control mode, the control loop of the digital power supply is completely digitized. After the feedback voltage signal is converted into a digital signal by an analog-to-digital converter, the PID correction compensation and PWM signal adjustment are completed through the built-in program of the DSP chip. As shown in Figure 1, a digital power supply using a traditional digital control method compares the output voltage with a single reference value through an analog-to-digital converter ADC 11, and then converts it into a digital signal; the compensation circuit 12 according to the comparison result n_digital performs compensation control operation to generate corresponding digital duty ratio signal D_digital; DPWM module 13 converts the received digital duty ratio signal D_digital into a square wave drive signal, that is, PWM control signal to control the main power stage circuit 14 of the digital power supply The switching action of the power switch S _o in the circuit is used to adjust the output voltage. However, with this digital control method, both the analog-to-digital converter ADC 11 and the DPWM module 13 have a fixed circuit structure, so the steady-state performance and dynamic performance of the digital power supply are all realized by the compensation circuit 12, making the compensation of the digital power supply flexible. The accuracy is not good, and the dynamic response performance of the digital power supply is poor.

Contents of the invention

In view of this, the purpose of the present invention is to provide a novel digital power supply control circuit and control method, utilize the dynamic component of the compensation signal to adjust the reference value of the analog-to-digital converter ADC in real time, improve the adjustment speed of the digital power supply control circuit, improve The dynamic response performance of the digital power supply is improved.

A digital power supply control circuit according to an embodiment of the present invention is applied to a digital power supply, including:

An analog-to-digital converter, configured to receive the output voltage of the digital power supply and compare it with n reference values, and convert the comparison result into a digital error signal representing the error between the current output voltage of the digital power supply and the expected output voltage , n≥3;

The digital compensation circuit receives the digital error signal to generate a digital duty cycle signal accordingly; wherein the dynamic component of the digital duty cycle signal is transmitted to the analog-to-digital converter to change the set of references accordingly the numeric value of the value;

The DPWM module generates a PWM control signal to control the switching action of the power switch in the digital power supply according to the received digital duty ratio signal, so as to ensure that the output voltage of the digital power supply is consistent with the expected output voltage, and, when When the output voltage of the digital power supply is inconsistent with the expected output voltage, it is ensured that the output voltage of the digital power supply quickly recovers to the expected output voltage.

Further, the number n of the reference values is an odd number, and the values of the n reference values center on the expected output voltage of the digital power supply and are distributed on both sides of the expected output voltage of the digital power supply.

Further, the analog-to-digital converter includes n comparators, the first input terminals of the n comparators receive the output voltage of the digital power supply, and the second input terminals respectively receive the n reference values.

Further, the analog-to-digital converter includes a digital decoder, configured to receive the output signals of the n comparators, and convert the output signals into the digital error signals.

Further, the analog-to-digital converter includes n digital-to-analog converters corresponding to the n reference values one-to-one;

According to the relationship between the dynamic component of the digital duty cycle signal and (n-1)/2 reference values, adjust the input signals of the n digital-to-analog converters; wherein, the (n-1)/2 The numerical value of a reference value is set according to the expected output current of the digital power supply, and decreases successively;

When the dynamic component of the digital duty cycle signal is smaller than the (n-1)/2th reference value, the n digital-to-analog converters maintain the current state;

When the dynamic component of the digital duty cycle signal is greater than the first reference value, the input signals of the n digital-to-analog converters are all decremented by 1;

When the dynamic component of the digital duty cycle signal is less than the first reference value and greater than the second reference value, the input signals of the second digital-to-analog converter to the n-1th digital-to-analog converter are all decremented by 1;

When the dynamic component of the digital duty cycle signal is less than the second reference value and greater than the third reference value, the input signals of the third digital-to-analog converter to the n-2th digital-to-analog converter are all decremented by 1;

By analogy, when the dynamic component of the digital duty ratio signal is smaller than the kth reference value and greater than the k+1th reference value, the input signals of the k+1th digital-to-analog converter to the n-kth digital-to-analog converter are all reduced by 1 ;

The output signals of the n digital-to-analog converters are used as the n reference values.

Further, the analog-to-digital converter also includes n counters and (n-1)/2 registers; wherein, the (n-1)/2 reference values are respectively stored in the (n-1)/ Among the two registers; the n counters are connected to the n digital-to-analog converters in one-to-one correspondence.

A digital power supply control method according to an embodiment of the present invention, applied to a digital power supply, includes the following steps:

sampling the output voltage of the digital power supply;

Comparing the output voltage of the digital power supply with the n reference values respectively to obtain n comparison signals;

converting the n comparison signals into digital error signals representing the error between the current output voltage and the expected output voltage of the digital power supply, n≥3;

generating the digital duty ratio signal according to the digital error signal;

According to the digital duty cycle signal, a PWM control signal is generated to control the switching action of the power switch in the digital power supply, so as to ensure that the output voltage of the digital power supply is consistent with the expected output voltage, and when the output of the digital power supply When the voltage is inconsistent with the expected output voltage, it is ensured that the output voltage of the digital power supply quickly recovers to the expected output voltage.

Further, the number n of the reference values is an odd number, and the values of the n reference values center on the expected output voltage of the digital power supply and are distributed on both sides of the expected output voltage of the digital power supply.

Further, the generation of the n reference values includes the following steps:

Sampling the dynamic component of the digital duty cycle signal of the digital power supply;

comparing the dynamic component of the digital duty cycle signal with (n-1)/2 reference values; the values of the (n-1)/2 reference values are set according to the desired output voltage of the digital power supply , and in descending order;

When the dynamic component of the digital duty ratio signal is smaller than the (n-1)/2th reference value, the n digital-to-analog converters maintain the current state;

When the dynamic component of the digital duty cycle signal is greater than the first reference value, the input signals of the n digital-to-analog converters are all decremented by 1;

When the dynamic component of the digital duty ratio signal is smaller than the kth reference value and greater than the k+1th reference value, the input signals of the k+1th digital-to-analog converter to the n-kth digital-to-analog converter are all reduced by 1;

The output signals of the n digital-to-analog converters are used as n reference values.

A digital power supply according to an embodiment of the present invention includes any of the digital power supply control circuits described above, and also includes a power stage circuit; the PWM control signal output by the digital power supply control circuit controls the digital power supply in the digital power supply The switching action of the power switch ensures that the output voltage of the digital power supply is consistent with the expected output voltage, and, when the output voltage of the digital power supply is inconsistent with the expected output voltage, ensures that the output voltage of the digital power supply quickly recovers to the desired output voltage.

According to the digital power supply control circuit and control method of the embodiments of the present invention, the dynamic components of the digital duty cycle signal of the compensation circuit are used to adjust multiple reference values of the analog-to-digital converter ADC in real time, and the dynamic components represent the current state of the digital power supply. The error information of the output voltage, therefore, the adjustment of the reference value with said dynamic component reflects the current error information. When the dynamic component is small, the adjustment to the reference value is correspondingly small; when the dynamic component is large, the adjustment to the reference value is correspondingly increased. Through this adjustment, the output of the analog-to-digital converter ADC can quickly follow the error information of the current output voltage, so that the subsequent compensation circuit can quickly respond to this error information, that is, quickly adjust the digital duty cycle signal to realize the rapid adjustment of the power switch of the digital power supply, and the output voltage is quickly adjusted accordingly, which significantly improves the dynamic response performance of the digital power supply.

Description of drawings

Fig. 1 shows a functional block diagram of a digital power supply in the prior art;

FIG. 2 is a schematic block diagram of a digital power supply control circuit according to an embodiment of the present invention;

FIG. 3 is a functional block diagram of a digital power supply control circuit according to another embodiment of the present invention;

FIG. 4 is a flowchart of a digital power control method according to an embodiment of the present invention;

FIG. 5 is a flowchart of a method for generating n reference values according to an embodiment of the present invention;

FIG. 6 is a schematic block diagram of a digital power supply according to the present invention.

Detailed ways

Several preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, but the present invention is not limited to these embodiments. The present invention covers any alternatives, modifications, equivalent methods and schemes made on the spirit and scope of the present invention. In order to provide the public with a thorough understanding of the present invention, specific details are set forth in the following preferred embodiments of the present invention, but those skilled in the art can fully understand the present invention without the description of these details.

Referring to FIG. 2 , it shows a functional block diagram of a digital power supply control circuit according to an embodiment of the present invention. In this embodiment, the digital power supply control circuit 200 includes an analog-to-digital converter ADC 23, a digital compensation circuit 22 and a DPWM module 21.

Wherein, the analog-to-digital converter 23 receives the output voltage V _out of the digital power supply and compares it with n reference values (V _ref1 , V _ref2 , V _ref3 ... V _refn ), and the comparison result is converted into the current The digital error signal E_digital of the error between the output voltage and the expected output voltage, where n takes the value n≥3;

Further, the number of the n reference values is an odd number, and the values of the n reference values center on the expected output voltage of the digital power supply and are distributed on both sides of the expected output voltage of the digital power supply. For example, the n reference values can be set as an arithmetic sequence, and the value of the (n+1)/2th reference value is consistent with the expected output voltage, then the n reference values are based on the expected output voltage as center, evenly distributed on both sides of the desired output voltage. According to the teaching of the present invention, those skilled in the art can know that the numerical ranges of n reference values in any other suitable form can be applicable to the embodiments of the present invention.

The digital compensation circuit 22 receives the digital error signal E_digital, and generates a corresponding digital duty ratio signal D_digital accordingly; wherein the dynamic component ΔD_digital of the digital duty ratio signal D_digital is fed back to the analog-to-digital converter 23 to adjust n in real time Numerical values of reference values (V _ref1 , V _ref2 , V _ref3 ... V _refn );

The DPWM module 21 receives the digital duty ratio signal D_digital, and outputs a PWM control signal using an on-chip timer and other circuits to drive the on and off states of the power switch tube in the digital power supply to ensure that the output voltage of the digital power supply is consistent with The expected output voltage is consistent, and when the output voltage of the digital power supply is inconsistent with the expected output voltage, it is ensured that the output voltage of the digital power supply quickly recovers to the expected output voltage.

Here, the analog-to-digital converter ADC 23 may include a reference value generating circuit 201, n comparators (202-2, 202-2, 202-3...202-n) and a digital decoder 203.

The reference value generating circuit ₂₀₁ adjusts the values of n reference values (V _ref1 , V _ref2 , V _ref3 . The dynamic component ΔD_digital of the digital duty ratio signal represents the error information between the current output voltage and the expected output voltage of the digital power supply. When the dynamic component ΔD_digital of the digital duty cycle signal is small, the error between the current output voltage representing the digital power supply and the expected output voltage is small, therefore, only n reference values (V _ref1 , V _ref2 , V _ref3 ... V _refn ) for adjustment. When the dynamic component ΔD_digital of the digital duty cycle signal is large, the error between the current output voltage and the expected output voltage representing the digital power supply is relatively large. Therefore, at this time, the n reference values (V _ref1 , V _ref2 , V _ref3 ... V _refn ) to adjust all or most of the values.

The inverting input terminals of n comparators (202-1, 202-2, 202-3...202-n) respectively receive the output voltage Vout of the digital power supply, and can also be the feedback voltage representing the output voltage of the digital power supply, in phase The input terminals respectively receive the n reference values (V _ref1 , V _ref2 , V _ref3 ... V _refn ) and the output signals of n comparators (202-1, 201-2, 201-3 ... 201-n) Characterizes the error information between the current output voltage and the expected output voltage.

The digital decoder 203 converts the received output signals of the n comparators (202-1, 201-2, 201-3...201-n) into a digital error signal E_digital, and then inputs it to the digital compensation circuit 22 .

It can be seen that the digital power supply control circuit shown in FIG. 2 according to the embodiment of the present invention uses the dynamic component of the digital duty cycle signal of the digital compensation circuit 22 to adjust the multiple reference values of the analog-to-digital converter ADC in real time. The dynamic component It characterizes the error information of the current output voltage of the digital power supply, therefore, the adjustment of the reference value by using the dynamic component reflects the current error information. When the dynamic component is small, the adjustment to the reference value is correspondingly small, and when the dynamic component is large, the adjustment to the reference value is correspondingly increased. Through the above adjustment of the reference value, the output of the analog-to-digital converter ADC can quickly follow the error information of the current output voltage, so that the subsequent compensation circuit can quickly respond to this error information, that is, quickly adjust the digital The duty cycle signal is used to realize the rapid adjustment of the power switch of the digital power supply, and the output voltage is adjusted quickly, which significantly improves the dynamic response performance of the digital power supply.

Referring to FIG. 3 , it is a functional block diagram of a digital power supply control circuit according to another embodiment of the present invention. On the basis of the embodiment shown in FIG. 2 , this embodiment further details a specific implementation of the reference voltage generating circuit. The working principle of the reference voltage generating circuit will be described in detail below, and the same parts as those in the embodiment shown in FIG. 2 will not be repeated.

In this embodiment, the reference voltage generating circuit 201 includes n digital-to-analog converters (DAC1, DAC2, DAC3...DACn), n counters, (n-1)/2 registers and a processor DSP. Wherein, the (n-1)/2 registers respectively have (n-1)/2 reference values (REF1, REF2, REF3...REF(n-1)/2), the (n- The values of 1)/2 reference values decrease successively, and are set accordingly according to the expected output voltage of the digital power supply; for example, it can be selected as a decreasing arithmetic sequence. The n counters are respectively connected to one of the corresponding n digital-to-analog converters (DAC1, DAC2, DAC3...DACn).

The dynamic component ΔD_digital of the digital duty ratio signal is numerically compared with the (n-1)/2 reference values (REF1, REF2, REF3...REF(n-1)/2) in the processor DSP ,

When the dynamic variable is smaller than the (n-1)/2th reference value, the input signals of the n digital-to-analog converters maintain the current state;

When the dynamic component ΔD_digital of the digital duty cycle signal is greater than the first reference value REF1, the input signals of the n digital-to-analog converters are decremented by 1 through counters 1 to 1;

When the dynamic component ΔD_digital of the digital duty cycle signal is less than the first reference value REF1 and greater than the second reference value REF2, the input signal from the second digital-to-analog converter to the n-1th digital-to-analog converter passes through the counter 2 to the counter (n-1) are all minus 1;

When the dynamic component ΔD_digital of the digital duty ratio signal is less than the second reference value REF2 and greater than the third reference value REF3, the input signal from the third digital-to-analog converter to the n-2th digital-to-analog converter passes through the counter 3 to the counter (n-2) minus 1;

By analogy, when the dynamic component ΔD_digital of the digital duty cycle signal is less than the kth reference value REFk and greater than the k+1th reference value REF(k+1), the k+1th digital-to-analog converter to the n-kth digital-to-analog converter The input signal of the converter is decremented by 1 from the counter k+1 to the counter n-k;

Output signals of the n digital-to-analog converters are used as the n reference values (V _ref1 , V _ref2 , V _ref3 . . . V _refn ).

The digital power supply control circuit shown in FIG. 3 according to the embodiment of the present invention uses the dynamic component of the digital duty cycle signal of the digital compensation circuit 22 to adjust n reference values of the analog-to-digital converter ADC in real time. According to the position of the dynamic component of the current digital duty cycle signal within a range of values represented by (n-1)/2 reference values (REF1, REF2, REF3...REF(n-1)/2), the corresponding A set of digital signals are obtained by a counter, and then converted by a digital-to-analog converter to obtain the n reference values (V _ref1 , V _ref2 , V _ref3 . . . V _refn ).

The dynamic component represents the error information of the current output voltage of the digital power supply. Therefore, the adjustment of the reference value using the dynamic component reflects the current error information. When the dynamic component is small, the adjustment of the reference value corresponds to is also smaller, and when the dynamic component is larger, the adjustment to the reference value is correspondingly increased. Therefore, the output of the analog-to-digital converter ADC can quickly follow the error information of the current output voltage, so that the subsequent compensation circuit can quickly respond to this error information, that is, quickly adjust the digital duty ratio signal to The fast adjustment of the power switch of the digital power supply is realized, and the output voltage is adjusted quickly accordingly, which significantly improves the dynamic response performance of the digital power supply.

Referring to FIG. 4, it shows a flow chart of a digital power supply control method according to an embodiment of the present invention, including the following steps:

S401: sampling the output voltage of the digital power supply;

S402: Comparing the output voltage of the digital power supply with n reference values (V _ref1 , V _ref2 , V _ref3 ... V _refn ) respectively to obtain n comparison signals, n≥3;

S403: Convert the n comparison signals into digital error signals representing the error between the current output voltage and the expected output voltage of the digital power supply;

S404: Generate a digital duty ratio signal according to the digital error signal, and adjust the values of the n reference values according to a dynamic component of the digital duty ratio signal;

S405: According to the digital duty cycle signal, generate a PWM control signal to control the switching action of the power switch in the digital power supply, to ensure that the output voltage of the digital power supply is consistent with the expected output voltage, and, when the digital power supply When the output voltage of the digital power supply is inconsistent with the expected output voltage, it is ensured that the output voltage of the digital power supply quickly recovers to the expected output voltage.

Wherein, the number of the n reference values is an odd number, and the values of the n reference values decrease successively, and are distributed on both sides of the expected output voltage of the digital power supply. The numerical values of the n reference values can be set accordingly according to actual needs, for example, the numerical values of the n reference values can be set as an arithmetic progression, and the numerical value of the (n+1)/2th reference value is the same as If the expected output voltages are consistent, the n reference values are centered on the expected output voltage and evenly distributed on both sides of the expected output voltage. According to the teaching of the present invention, those skilled in the art can know that the numerical ranges of n reference values in any other suitable form can be applicable to the embodiments of the present invention.

Moreover, the values of the n reference values can be adjusted in real time according to the dynamic component of the digital duty ratio signal, and the dynamic component of the digital duty ratio signal represents the difference between the current output voltage and the expected output voltage of the digital power supply. Error information, therefore, when the dynamic component of the digital duty cycle signal is large, it means that the error between the current output voltage of the digital power supply and the expected output voltage is large, at this time, all or all of the n reference values Part of the numerical value is adjusted to be closer to the expected output voltage of the digital power supply to enhance the adjustment effect; when the dynamic component of the digital duty cycle signal is small, it means that the error between the current output voltage of the digital power supply and the expected output voltage is relatively small. Small, if the error is small enough, the values of the n reference values may not be adjusted; if the error is slightly larger, the values of some of the reference values in the n reference values are adjusted to approach the expected output voltage of the digital power supply.

Therefore, according to the digital power supply control method of the embodiment of the present invention, the digital error signal can quickly track the error information of the current output voltage, so as to respond quickly to this error information, that is, to quickly adjust the digital duty ratio signal, To realize the rapid adjustment of the power switch of the digital power supply, the output voltage is quickly adjusted accordingly, and the dynamic response performance of the digital power supply is significantly improved.

Referring to FIG. 5 , it shows a flowchart of a method for generating n reference values according to an embodiment of the present invention, which includes the following steps:

S501: sampling the dynamic component of the digital duty ratio signal of the digital power supply;

S502: Compare the dynamic component with (n-1)/2 reference values;

The values of the (n-1)/2 reference values are sequentially decremented; the values of the (n-1)/2 reference values are set according to the expected output voltage of the digital power supply;

S503: When the dynamic component is smaller than the (n-1)/2th reference value, the n digital-to-analog converters corresponding to the n reference values one-to-one maintain the current state;

S504: When the dynamic component is greater than the first reference value, the input signals of the n digital-to-analog converters are all decremented by 1;

S505: When the dynamic variable is smaller than the kth reference value but larger than the k+1th reference value, the input signals of the k+1th digital-to-analog converter to the n-kth digital-to-analog converter are all decremented by 1;

Further, the change of the input signal of the digital-to-analog converter can be realized through n counters corresponding to the n digital-to-analog converters one-to-one;

S506: The output signals of the n digital-to-analog converters are used as n reference values.

Through the above method for generating n reference values according to the embodiment of the present invention, according to the position of the dynamic variable within a numerical range determined by (n-1)/2 reference values, correspondingly through a group of counters Adjust the values of all or part of the n reference values.

Referring to FIG. 6 , it is a functional block diagram of a digital power supply according to an embodiment of the present invention. In this embodiment, the digital power supply 600 includes a power stage circuit 601 and a digital power supply control circuit 602 . Wherein, the power stage circuit 601 may be a step-down type, a step-up type, a step-up-buck type or an isolated topology including a power switch, a rectifier switch, an inductor and a filter circuit; the digital power supply control circuit 602 may be the above-mentioned Any digital power supply control circuit according to an embodiment of the present invention, as shown in FIG. 2 and FIG. 3 , and reasonable modifications based on the above-mentioned embodiments disclosed in the present invention.

The PWM control signal output by the digital power supply control circuit controls the switching action of the power switch in the digital power supply to ensure that the output voltage of the digital power supply is consistent with the expected output voltage, and when the output voltage of the digital power supply is consistent with When the expected output voltages are inconsistent, it is ensured that the output voltage of the digital power supply quickly recovers to the expected output voltage.

It should be noted that the devices with the same name have the same functions among the various embodiments of the present invention, and the improved embodiments can be combined with the above-mentioned multiple related embodiments, but the description is only on the basis of the previous embodiment The above example illustrates. Moreover, the above is only taking the circuit shown in Figure 2 and Figure 3 as an example to illustrate the digital power supply control circuit in this embodiment, but the structures of these two circuits include but are not limited to the forms disclosed above, as long as it can realize The functions of the relevant circuits described in the embodiments of the present invention are sufficient. Therefore, relevant improvements made by those skilled in the art on the basis of the circuits disclosed in the embodiments of the present invention are also within the protection scope of the embodiments of the present invention.

In addition, it should also be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that these entities or operations, any such actual relationship or order exists. Furthermore, the term "comprises", "comprises" or any other variation thereof is intended to cover a non-exclusive inclusion such that a process, method, article, or apparatus comprising a set of elements includes not only those elements, but also includes elements not expressly listed. other elements of or also include elements inherent in such a process, method, article, or device. Without further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article or apparatus comprising said element.

Embodiments according to the present invention are described above, and these embodiments do not describe all details in detail, nor do they limit the invention to only the specific embodiments described. Obviously many modifications and variations are possible in light of the above description. This description selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can make good use of the present invention and its modification on the basis of the present invention. The invention is to be limited only by the claims, along with their full scope and equivalents.

Claims (10)

1. A digital power supply control circuit, applied in a digital power supply, is characterized in that, comprising: An analog-to-digital converter, configured to receive the output voltage of the digital power supply and compare it with n reference values, and convert the comparison result into a digital error signal representing the error between the current output voltage of the digital power supply and the expected output voltage , n≥3; The digital compensation circuit receives the digital error signal to generate a digital duty cycle signal accordingly; wherein the dynamic component of the digital duty cycle signal is transmitted to the analog-to-digital converter to change the set of references accordingly the numeric value of the value; The DPWM module generates a PWM control signal to control the switching action of the power switch in the digital power supply according to the received digital duty ratio signal, so as to ensure that the output voltage of the digital power supply is consistent with the expected output voltage, and, when When the output voltage of the digital power supply is inconsistent with the expected output voltage, it is ensured that the output voltage of the digital power supply quickly recovers to the expected output voltage. 2. The digital power supply control circuit according to claim 1, wherein n is an odd number, and the numerical values of the n reference values are centered on the expected output voltage of the digital power supply and distributed in the expected output voltage of the digital power supply. both sides of the output voltage. 3. The digital power supply control circuit according to claim 2, wherein the analog-to-digital converter comprises n comparators, and the first input terminals of the n comparators receive the output voltage of the digital power supply, The second input end respectively receives the n reference values. 4. The digital power supply control circuit according to claim 3, wherein the analog-to-digital converter includes a digital decoder for receiving the output signals of the n comparators and converting the output signals is the digital error signal. 5. The digital power supply control circuit according to claim 2, wherein the analog-to-digital converter comprises n digital-to-analog converters corresponding to the n reference values one-to-one; According to the relationship between the dynamic component of the digital duty cycle signal and (n-1)/2 reference values, adjust the input signals of the n digital-to-analog converters; wherein, the (n-1)/2 The numerical value of a reference value is set according to the expected output current of the digital power supply, and decreases successively; When the dynamic component of the digital duty cycle signal is smaller than the (n-1)/2th reference value, the n digital-to-analog converters maintain the current state; When the dynamic component of the digital duty cycle signal is greater than the first reference value, the input signals of the n digital-to-analog converters are all decremented by 1; When the dynamic component of the digital duty cycle signal is less than the first reference value and greater than the second reference value, the input signals of the second digital-to-analog converter to the n-1th digital-to-analog converter are all decremented by 1; When the dynamic component of the digital duty cycle signal is less than the second reference value and greater than the third reference value, the input signals of the third digital-to-analog converter to the n-2th digital-to-analog converter are all decremented by 1; By analogy, when the dynamic component of the digital duty cycle signal is smaller than the kth reference value and greater than the k+1th reference value, the input signals of the k+1th digital-to-analog converter to the n-kth digital-to-analog converter are all reduced by 1 ; The output signals of the n digital-to-analog converters are used as the n reference values. 6. digital power supply control circuit according to claim 5, is characterized in that, described analog-to-digital converter also comprises n counters and (n-1)/2 registers; Wherein, described (n-1)/ The two reference values are respectively stored in the (n-1)/2 registers; the n counters are connected to the n digital-to-analog converters in one-to-one correspondence. 7. A digital power supply control method, applied in a digital power supply, is characterized in that, comprising the following steps: sampling the output voltage of the digital power supply; Comparing the output voltage of the digital power supply with the n reference values respectively to obtain n comparison signals; converting the n comparison signals into digital error signals representing the error between the current output voltage and the expected output voltage of the digital power supply, n≥3; generating the digital duty ratio signal according to the digital error signal; According to the digital duty cycle signal, a PWM control signal is generated to control the switching action of the power switch in the digital power supply, so as to ensure that the output voltage of the digital power supply is consistent with the expected output voltage, and when the output of the digital power supply When the voltage is inconsistent with the expected output voltage, it is ensured that the output voltage of the digital power supply quickly recovers to the expected output voltage. 8. The digital power supply control method according to claim 7, wherein n is an odd number, and the numerical values of the n reference values are centered on the expected output voltage of the digital power supply and distributed in the expected output voltage of the digital power supply. both sides of the output voltage. 9. digital power supply control method according to claim 8, is characterized in that, the generation of described n reference values comprises the following steps: Sampling the dynamic component of the digital duty cycle signal of the digital power supply; comparing the dynamic component of the digital duty cycle signal with (n-1)/2 reference values; the values of the (n-1)/2 reference values are set according to the desired output voltage of the digital power supply , and in descending order; When the dynamic component of the digital duty ratio signal is smaller than the (n-1)/2th reference value, the n digital-to-analog converters maintain the current state; When the dynamic component of the digital duty cycle signal is greater than the first reference value, the input signals of the n digital-to-analog converters are all decremented by 1; When the dynamic component of the digital duty ratio signal is smaller than the kth reference value and greater than the k+1th reference value, the input signals of the k+1th digital-to-analog converter to the n-kth digital-to-analog converter are all reduced by 1; The output signals of the n digital-to-analog converters are used as n reference values. 10. A digital power supply, characterized in that it includes any digital power supply control circuit according to claims 1-6, and also includes a power stage circuit; the PWM control signal output by the digital power supply control circuit controls the digital power supply The switching action of the power switch in the power supply ensures that the output voltage of the digital power supply is consistent with the expected output voltage, and, when the output voltage of the digital power supply is inconsistent with the expected output voltage, ensures that the output voltage of the digital power supply recovers quickly to the desired output voltage.

Images