Conduction duration adjusting circuit, DC-DC voltage conversion circuit and chip

Abstract

The invention discloses a conduction duration adjusting circuit, a DC-DC voltage conversion circuit and a chip, and the conduction duration adjusting circuit comprises a sampling module which is configured to collect a load current in the DC-DC voltage conversion circuit and generate a corresponding load voltage; the digital circuit module is used for receiving load voltage and generating conduction duration generation voltage; the conduction duration generation module receives the conduction duration generation voltage and the input voltage of the DC-DC voltage conversion circuit, adjusts the conduction duration of a synchronous tube in the DC-DC voltage conversion circuit by using the conduction duration generation voltage and the input voltage, and generates a conduction duration signal; the conduction duration signal is used for stabilizing the working frequency of the DC-DC voltage conversion circuit. Through the mode, the problem that the working frequency of the DC-DC voltage conversion circuit changes along with the change of the load is solved.

Description

Technical Field

[0001] This application relates to the field of electronic circuit technology, and in particular to conduction duration adjustment circuits, DC-DC voltage conversion circuits and chips. Background Technology

[0002] During the operation of a DC-DC voltage conversion circuit, although the on-time of each cycle can be set to be proportional to the output voltage of the DC-DC voltage conversion circuit and inversely proportional to the input voltage of the DC-DC voltage conversion circuit, the operating frequency of the DC-DC voltage conversion circuit can remain constant under different input voltages and different output voltages.

[0003] However, due to voltage drops in components such as the sync transistor, rectifier transistor, circuit, and wiring in the DC-DC voltage conversion circuit, the actual operating duty cycle of the DC-DC voltage conversion circuit is less than the ideal duty cycle. Furthermore, the operating frequency increases with the increase of load current and junction temperature. Summary of the Invention

[0004] This application provides a conduction duration adjustment circuit, a DC-DC voltage conversion circuit and chip, which solves the problem that the operating frequency of the DC-DC voltage conversion circuit changes with the load.

[0005] To solve the above-mentioned technical problems, one technical solution adopted in this application is: providing a conduction duration adjustment circuit for use in a DC-DC voltage conversion circuit, comprising: a sampling module configured to acquire the load current in the DC-DC voltage conversion circuit and generate a corresponding load voltage; a digital circuit module receiving the load voltage and generating a conduction duration generation voltage; and a conduction duration generation module receiving the conduction duration generation voltage and the input voltage of the DC-DC voltage conversion circuit, adjusting the conduction duration of the synchronous transistor in the DC-DC voltage conversion circuit using the conduction duration generation voltage and the input voltage, and generating a conduction duration signal; the conduction duration signal is used to stabilize the operating frequency of the DC-DC voltage conversion circuit.

[0006] The digital circuit module is configured to generate voltage by looking up the corresponding conduction time in a table based on the load voltage.

[0007] The digital circuit module includes: an analog-to-digital converter that receives the load voltage and outputs a digital signal corresponding to the load voltage; and a digital control circuit that receives the digital signal and generates a voltage by looking up the corresponding conduction time in a table based on the digital signal.

[0008] The conduction duration generation module includes: a current mirror unit, which receives the input voltage and generates the target voltage; and a comparison unit, which receives the target voltage and the conduction duration generation voltage and generates the conduction duration signal.

[0009] The current mirror unit includes: an error amplifier that receives the input voltage and generates an error signal; a transistor that receives the error signal; a current mirror whose first end is coupled to the first end of the transistor; a resistive element whose first end is coupled to the second end of the transistor and the error amplifier, and whose second end is grounded; and a capacitor whose first end is coupled to the second end of the current mirror, and whose second end is grounded. The coupling point between the capacitor and the current mirror generates the target voltage.

[0010] Among them, the conduction time of the synchronizing tube increases with the increase of the load current, and decreases with the decrease of the load current.

[0011] To solve the above-mentioned technical problems, another technical solution adopted in this application is to provide a DC-DC voltage conversion circuit, which includes the conduction time adjustment circuit provided by the above technical solution.

[0012] The DC-DC voltage conversion circuit further includes: a logic control module that receives a first modulation signal and a conduction duration signal, and generates a second modulation signal; the second modulation signal is used to control the conduction of the synchronous transistor in the DC-DC voltage conversion circuit.

[0013] The logic control module uses the rising edge of the first modulation signal in the current period as the start time of the second modulation signal and the rising edge of the conduction duration signal in the current period as the end time of the second modulation signal. The rising edge of the conduction duration signal in the current period is located after the rising edge of the first modulation signal in the current period.

[0014] To solve the above-mentioned technical problems, another technical solution adopted in this application is to provide a DC-DC voltage conversion chip, which includes the conduction time adjustment circuit or the DC-DC voltage conversion circuit provided by the above-mentioned technical solution.

[0015] The beneficial effects of the embodiments of this application are as follows: Unlike the prior art, the conduction duration adjustment circuit, DC-DC voltage conversion circuit, and chip provided in this application utilize a sampling module to collect the load current in the DC-DC voltage conversion circuit and generate a corresponding load voltage; and utilize a digital circuit module to receive the load voltage and generate a conduction duration generation voltage; and utilize a conduction duration generation module to receive the conduction duration generation voltage and the input voltage of the DC-DC voltage conversion circuit, thereby adjusting the conduction duration of the synchronous transistor in the DC-DC voltage conversion circuit using the conduction duration generation voltage and the input voltage, generating a conduction duration signal. This conduction duration signal can stabilize the operating frequency of the DC-DC voltage conversion circuit, thus solving the problem of the DC-DC voltage conversion circuit's operating frequency changing with load variations. In other words, the impact of load changes on the DC-DC voltage conversion circuit's operating frequency is reduced, maintaining a stable operating frequency. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] in:

[0018] Figure 1 This is a schematic diagram of the structure of the first embodiment of the conduction duration adjustment circuit provided in this application;

[0019] Figure 2 This is a schematic diagram of the structure of the second embodiment of the conduction duration adjustment circuit provided in this application;

[0020] Figure 3 This is a schematic diagram of the third embodiment of the conduction duration adjustment circuit provided in this application;

[0021] Figure 4 This is a schematic diagram of the structure of an embodiment of the conduction duration generation module provided in this application;

[0022] Figure 5 This is a schematic diagram of the structure of the first embodiment of the DC-DC voltage conversion circuit provided in this application;

[0023] Figure 6 This is a schematic diagram of the structure of a second embodiment of the DC-DC voltage conversion circuit provided in this application;

[0024] Figure 7 This is a waveform diagram of the relevant signal corresponding to the load change in the DC-DC voltage conversion circuit in related technologies;

[0025] Figure 8 This is a waveform diagram of the relevant signals corresponding to load changes in the DC-DC voltage conversion circuit provided in this application;

[0026] Figure 9 This is a schematic diagram of the structure of the first embodiment of the DC-DC voltage conversion chip provided in this application;

[0027] Figure 10 This is a schematic diagram of the structure of a second embodiment of the DC-DC voltage conversion chip provided in this application;

[0028] Figure 11 This is a schematic diagram of the third embodiment of the DC-DC voltage conversion chip provided in this application. Detailed Implementation

[0029] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. It is understood that the specific embodiments described herein are only for explaining this application and not for limiting it. Furthermore, it should be noted that, for ease of description, only the parts related to this application are shown in the accompanying drawings, not all structures. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0030] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0031] During the operation of a DC-DC voltage conversion circuit, although the on-time of each cycle can be set to be proportional to the output voltage of the DC-DC voltage conversion circuit and inversely proportional to the input voltage of the DC-DC voltage conversion circuit, the operating frequency of the DC-DC voltage conversion circuit can remain constant under different input voltages and different output voltages.

[0032] However, due to voltage drops in components such as the sync transistor, rectifier transistor, circuit, and wiring in the DC-DC voltage conversion circuit, the actual operating duty cycle of the DC-DC voltage conversion circuit is less than the ideal duty cycle. Furthermore, the operating frequency increases with the increase of load current and junction temperature.

[0033] Based on this, this application proposes to incorporate a conduction duration adjustment circuit into the DC-DC voltage conversion circuit. The sampling module within the conduction duration adjustment circuit acquires the load current in the DC-DC voltage conversion circuit to generate a corresponding load voltage. A digital circuit module within the conduction duration adjustment circuit receives the load voltage and generates a conduction duration generation voltage. The conduction duration generation module within the conduction duration adjustment circuit receives the conduction duration generation voltage and the input voltage of the DC-DC voltage conversion circuit. The conduction duration generation voltage and the input voltage are then used to adjust the conduction duration of the synchronizing transistor in the DC-DC voltage conversion circuit, generating a conduction duration signal. This conduction duration signal stabilizes the operating frequency of the DC-DC voltage conversion circuit, thereby solving the problem of the DC-DC voltage conversion circuit's operating frequency changing with load variations. In other words, the impact of load changes on the DC-DC voltage conversion circuit's operating frequency is reduced, maintaining a stable operating frequency. See any of the following technical solutions for details.

[0034] See Figure 1 , Figure 1 This is a schematic diagram of the first embodiment of the conduction duration adjustment circuit provided in this application. Applied to a DC-DC voltage conversion circuit, the conduction duration adjustment circuit 100 includes: a sampling module 10, a digital circuit module 20, and a conduction duration generation module 30.

[0035] The sampling module 10 is configured to acquire the load current Isense in the DC-DC voltage conversion circuit and generate a corresponding load voltage. In some embodiments, the load current Isense may be the current flowing through the inductor in the DC-DC voltage conversion circuit.

[0036] Digital circuit module 20 receives the load voltage Vsense and generates a conduction duration voltage VON_TIME. In some embodiments, digital circuit module 20 may include a storage circuit. This storage circuit may store a corresponding relationship table, such as a relationship table between the load voltage Vsense and the conduction duration voltage VON_TIME. After receiving the load voltage Vsense, digital circuit module 20 can obtain the corresponding conduction duration voltage VON_TIME by querying the relationship table. The relationship table between the load voltage Vsense and the conduction duration voltage VON_TIME can be obtained in advance through artificial experiments. There is a positive correlation between the load voltage Vsense and the conduction duration voltage VON_TIME. That is, the conduction duration voltage VON_TIME increases as the load voltage Vsense increases, and decreases as the load voltage Vsense decreases.

[0037] In some embodiments, the synchronous transistor in the DC-DC voltage conversion circuit has a default on-time duration. The storage circuit in the digital circuit module 20 can store a corresponding relationship table, such as a relationship table between the load voltage Vsense and the on-time increment voltage. After receiving the load voltage Vsense, the digital circuit module 20 can obtain the on-time increment voltage corresponding to the load voltage Vsense by querying the relationship table. The relationship table between the load voltage Vsense and the on-time increment voltage can be obtained in advance through manual experimentation. Then, the on-time generation voltage VON_TIME is obtained based on the on-time increment voltage and the default on-time duration.

[0038] The conduction duration generation module 30 receives the conduction duration generation voltage VON_TIME and the input voltage of the DC-DC voltage conversion circuit, and uses the conduction duration generation voltage VON_TIME and the input voltage to adjust the conduction duration of the synchronous tube in the DC-DC voltage conversion circuit to generate the conduction duration signal TON.

[0039] In some embodiments, as the load on the DC-DC voltage conversion circuit increases, the load current Isense sampled by the sampling module 10 increases, and the load voltage Vsense corresponding to the load current Isense increases. The digital circuit module 20 generates a conduction duration generation voltage VON_TIME, which increases with the increase in load voltage Vsense. The increased conduction duration generation voltage VON_TIME is then used to generate a conduction duration signal TON. The conduction duration signal TON is used to stabilize the operating frequency of the DC-DC voltage conversion circuit.

[0040] The DC-DC voltage conversion circuit can control the conduction time of the synchronous tube in the DC-DC voltage conversion circuit based on the conduction duration signal TON.

[0041] In one application scenario, the operating frequency Fsw = D / TON. Here, D represents the duty cycle of the conduction signal TON, and TON represents the conduction duration. As the load voltage Vsense increases, the duty cycle of the conduction signal TON increases, and since the conduction duration also increases, the operating frequency Fsw only changes slightly compared to before the increase in load voltage Vsense, and tends to stabilize.

[0042] In this embodiment, a conduction duration adjustment circuit 100 is provided in the DC-DC voltage conversion circuit. The sampling module 10 in the conduction duration adjustment circuit 100 collects the load current Isense in the DC-DC voltage conversion circuit and generates a corresponding load voltage Vsense. The digital circuit module 20 in the conduction duration adjustment circuit 100 receives the load voltage Vsense and generates a conduction duration generation voltage VON_TIME. The conduction duration generation module 30 in the conduction duration adjustment circuit 100 receives the conduction duration generation voltage VON_TIME and the input voltage of the DC-DC voltage conversion circuit. Then, the conduction duration of the synchronous transistor in the DC-DC voltage conversion circuit is adjusted using the conduction duration generation voltage VON_TIME and the input voltage to generate a conduction duration signal TON. Thus, the conduction duration signal TON can stabilize the operating frequency of the DC-DC voltage conversion circuit, thereby solving the problem of the DC-DC voltage conversion circuit's operating frequency changing with load variations. That is, the impact of load changes on the DC-DC voltage conversion circuit's operating frequency is reduced, maintaining a stable operating frequency.

[0043] See Figure 2 , Figure 2 This is a schematic diagram of the second embodiment of the conduction duration adjustment circuit 100 provided in this application. Applied to a DC-DC voltage conversion circuit, the conduction duration adjustment circuit 100100 includes: a sampling module 10, a digital circuit module 20, and a conduction duration generation module 30.

[0044] The sampling module 10 is configured to acquire the load current Isense in the DC-DC voltage conversion circuit and generate a corresponding load voltage Vsense. In some embodiments, the load current Isense may be the current flowing through the inductor in the DC-DC voltage conversion circuit.

[0045] Digital circuit module 20 receives the load voltage Vsense and generates the conduction duration voltage VON_TIME.

[0046] The conduction duration generation module 30 receives the conduction duration generation voltage VON_TIME and the input voltage of the DC-DC voltage conversion circuit, and uses the conduction duration generation voltage VON_TIME and the input voltage to adjust the conduction duration of the synchronous tube in the DC-DC voltage conversion circuit to generate the conduction duration signal TON.

[0047] Furthermore, the digital circuit module 20 includes an analog-to-digital converter 21 and a digital control circuit 22.

[0048] The analog-to-digital converter 21 receives the load voltage Vsense and outputs the digital signal Vd corresponding to the load voltage Vsense.

[0049] The digital control circuit 22 receives the digital signal Vd and retrieves the corresponding on-time voltage VON_TIME from a data table based on Vd. In some embodiments, the digital control circuit 22 may include a storage circuit. This storage circuit may store corresponding data tables, index tables, or mapping relationships, such as a data table, index table, or mapping relationship between the load voltage Vsense and the on-time voltage VON_TIME. After receiving the digital signal Vd, the digital control circuit 22 can obtain the on-time voltage VON_TIME corresponding to the digital signal Vd by looking up a table or querying a mapping relationship. The data table between the digital signal Vd and the on-time voltage VON_TIME can be obtained in advance through artificial experimentation.

[0050] That is, the digital circuit module 20 is configured to generate a voltage VON_TIME by looking up the corresponding on-time based on the load voltage Vsense. The data table is stored in the digital circuit module 20. For example, the aforementioned index table can be stored in the digital circuit module 20, or in other areas accessible to the digital circuit module 20.

[0051] In other embodiments, the analog-to-digital converter 21 receives the load voltage Vsense and the input voltage VIN and output voltage VOUT of the DC-DC voltage conversion circuit, and outputs the corresponding digital signal Vd.

[0052] In this embodiment, a conduction duration adjustment circuit 100 is provided in the DC-DC voltage conversion circuit. The sampling module 10 in the conduction duration adjustment circuit 100 collects the load current Isense in the DC-DC voltage conversion circuit and generates a corresponding load voltage Vsense. The digital circuit module 20 in the conduction duration adjustment circuit 100 receives the load voltage Vsense and generates a conduction duration generation voltage VON_TIME. The conduction duration generation module 30 in the conduction duration adjustment circuit 100 receives the conduction duration generation voltage VON_TIME and the input voltage of the DC-DC voltage conversion circuit. Then, the conduction duration of the synchronous transistor in the DC-DC voltage conversion circuit is adjusted using the conduction duration generation voltage VON_TIME and the input voltage to generate a conduction duration signal TON. Thus, the conduction duration signal TON can stabilize the operating frequency of the DC-DC voltage conversion circuit, thereby solving the problem of the DC-DC voltage conversion circuit's operating frequency changing with load variations. That is, the impact of load changes on the DC-DC voltage conversion circuit's operating frequency is reduced, maintaining a stable operating frequency.

[0053] Furthermore, by using the digital control circuit 22 to query the corresponding conduction duration and generate voltage VON_TIME from the data table based on the digital signal Vd, the efficiency of obtaining the conduction duration and generating voltage VON_TIME can be accelerated.

[0054] See Figure 3 , Figure 3 This is a schematic diagram of the third embodiment of the conduction duration adjustment circuit 100 provided in this application. Applied to a DC-DC voltage conversion circuit, the conduction duration adjustment circuit 100100 includes: a sampling module 10, a digital circuit module 20, and a conduction duration generation module 30.

[0055] The sampling module 10 is configured to acquire the load current Isense in the DC-DC voltage conversion circuit and generate a corresponding load voltage Vsense. In some embodiments, the load current Isense may be the current flowing through the inductor in the DC-DC voltage conversion circuit.

[0056] Digital circuit module 20 receives the load voltage Vsense and generates the conduction duration voltage VON_TIME.

[0057] The conduction duration generation module 30 receives the conduction duration generation voltage VON_TIME and the input voltage VIN of the DC-DC voltage conversion circuit. It uses the conduction duration generation voltage VON_TIME and the input voltage VIN to adjust the conduction duration of the synchronous tube in the DC-DC voltage conversion circuit and generate the conduction duration signal TON.

[0058] Furthermore, the conduction duration generation module 30 includes a current mirror unit 31 and a comparison unit 32.

[0059] The current mirror unit 31 receives the input voltage VIN and generates the target voltage.

[0060] The comparison unit 32 receives the target voltage and the conduction duration to generate the voltage VON_TIME, and generates the conduction duration signal TON.

[0061] In this embodiment, the comparison unit 32 compares the target voltage with the conduction duration generation voltage VON_TIME to generate a conduction duration signal TON. If the target voltage remains below the conduction duration generation voltage VON_TIME, the conduction duration signal TON is continuously output. When the target voltage equals the conduction duration generation voltage VON_TIME, the output of the conduction duration signal TON stops.

[0062] In this embodiment, a conduction duration adjustment circuit 100 is provided in the DC-DC voltage conversion circuit. The sampling module 10 in the conduction duration adjustment circuit 100 collects the load current Isense in the DC-DC voltage conversion circuit and generates a corresponding load voltage Vsense. The digital circuit module 20 in the conduction duration adjustment circuit 100 receives the load voltage Vsense and generates a conduction duration generation voltage VON_TIME. The conduction duration generation module 30 in the conduction duration adjustment circuit 100 receives the conduction duration generation voltage VON_TIME and the input voltage VIN of the DC-DC voltage conversion circuit. Then, the conduction duration of the synchronous tube in the DC-DC voltage conversion circuit is adjusted using the conduction duration generation voltage VON_TIME and the input voltage VIN to generate a conduction duration signal TON. Thus, the conduction duration signal TON can stabilize the operating frequency of the DC-DC voltage conversion circuit, thereby solving the problem that the operating frequency of the DC-DC voltage conversion circuit changes with the load. That is, the load changes of the DC-DC voltage conversion circuit have less impact on the operating frequency of the DC-DC voltage conversion circuit, thus maintaining the stability of the operating frequency.

[0063] Furthermore, the comparison unit 32 compares the target voltage and the voltage VON_TIME generated by the conduction duration to generate the conduction duration signal TON, thereby enabling the conduction duration signal TON to stabilize the operating frequency of the DC-DC voltage conversion circuit.

[0064] See Figure 4 , Figure 4 This is a schematic diagram of an embodiment of the conduction duration generation module 30 provided in this application. The current mirror unit 31 includes: an error amplifier EA, a transistor Q1, a current mirror, a resistive element 301, and a capacitor C1.

[0065] Error amplifier EA receives input voltage VIN and generates an error signal.

[0066] Transistor Q1 receives the error signal.

[0067] The first terminal of the current mirror is coupled to the first terminal of transistor Q1. For example... Figure 4 As shown, the current mirror includes transistor Q2 and transistor Q3.

[0068] The first terminal of resistive element 301 is coupled to the second terminal of transistor Q1 and error amplifier EA, and the second terminal of resistive element 301 is grounded. Exemplarily, resistive element 301 can be a component or circuit that can be equivalent to a resistor and is disposed between transistor Q1 and ground; for example, a circuit composed of a resistive element or other transistors.

[0069] The first end of capacitor C1 is coupled to the second end of the current mirror, and the second end of capacitor C1 is grounded; the coupling point between capacitor C1 and the current mirror generates the target voltage.

[0070] Among them, the conduction time of the synchronizing tube increases with the increase of the load current Isense, and decreases with the decrease of the load current Isense.

[0071] Furthermore, combined with Figure 4 Explanation:

[0072] The non-inverting input of error amplifier EA receives the input voltage VIN, while the inverting input is grounded through resistor R1. Error amplifier EA generates an error signal based on the input voltage VIN, which is then input to the control terminal of transistor Q1 to turn on.

[0073] The current mirror provides a current I1 to charge capacitor C1. When the voltage across capacitor C1 equals the on-time voltage VON_TIME, a turn-off signal is generated, turning off the synchronizing transistor. Conversely, when the voltage across capacitor C1 is not equal to the on-time voltage VON_TIME, a synchronizing transistor on-time signal TON is generated. Here, the current I1 is equal to the input voltage VIN divided by the resistance of resistive element 301.

[0074] That is, in the DC-DC voltage conversion circuit, the conduction time of the synchronous transistor increases with the increase of the load current Isense, and the conduction time of the synchronous transistor decreases with the decrease of the load current Isense.

[0075] In other embodiments, the non-inverting input of the error amplifier EA receives the input voltage VIN and the reference voltage VREF, while the inverting input is grounded through resistive element 301. The error amplifier EA generates an error signal based on the input voltage VIN, which is then input to the control terminal of transistor Q1 to control transistor Q1 to turn on.

[0076] The current mirror provides a current I1 to charge capacitor C1. When the voltage across capacitor C1 equals the on-time voltage VON_TIME, a turn-off signal is generated, turning off the synchronizing transistor. Conversely, when the voltage across capacitor C1 is not equal to the on-time voltage VON_TIME, a synchronizing transistor on-time signal TON is generated. The current I1 is equal to (input voltage VIN + reference voltage VREF) divided by the resistance of resistive component 301.

[0077] In this embodiment, a conduction duration adjustment circuit 100 is provided in the DC-DC voltage conversion circuit. The sampling module 10 in the conduction duration adjustment circuit 100 collects the load current Isense in the DC-DC voltage conversion circuit and generates a corresponding load voltage Vsense. The digital circuit module 20 in the conduction duration adjustment circuit 100 receives the load voltage Vsense and generates a conduction duration generation voltage VON_TIME. The conduction duration generation module 30 in the conduction duration adjustment circuit 100 receives the conduction duration generation voltage VON_TIME and the input voltage VIN of the DC-DC voltage conversion circuit. Then, the conduction duration of the synchronous tube in the DC-DC voltage conversion circuit is adjusted using the conduction duration generation voltage VON_TIME and the input voltage VIN to generate a conduction duration signal TON. Thus, the conduction duration signal TON can stabilize the operating frequency of the DC-DC voltage conversion circuit, thereby solving the problem that the operating frequency of the DC-DC voltage conversion circuit changes with the load. That is, the load changes of the DC-DC voltage conversion circuit have less impact on the operating frequency of the DC-DC voltage conversion circuit, thus maintaining the stability of the operating frequency.

[0078] Furthermore, by using the digital control circuit 22 to query the corresponding conduction duration and generate voltage VON_TIME from the data table based on the digital signal Vd, the efficiency of obtaining the conduction duration and generating voltage VON_TIME can be accelerated.

[0079] See Figure 5 , Figure 5 This is a schematic diagram of the structure of a first embodiment of the DC-DC voltage conversion circuit provided in this application. The DC-DC voltage conversion circuit 200 includes an on-time adjustment circuit 100. The on-time adjustment circuit 100 is as described in any embodiment of this application.

[0080] See Figure 6 , Figure 6 This is a schematic diagram of the structure of a second embodiment of the DC-DC voltage conversion circuit provided in this application. The DC-DC voltage conversion circuit 200 includes an on-time adjustment circuit 100 and a logic control module.

[0081] The logic control module receives the first modulation signal PWM and the conduction duration signal TON, and generates a second modulation signal PWM'. The second modulation signal is used to control the conduction of the synchronous tube in the DC-DC voltage conversion circuit.

[0082] The logic control module uses the rising edge of the first modulation signal PWM in the current period as the start time of the second modulation signal PWM', and uses the rising edge of the conduction duration signal TON in the current period as the end time of the second modulation signal PWM'. The rising edge of the conduction duration signal TON in the current period is located after the rising edge of the first modulation signal PWM' in the current period.

[0083] In some embodiments, combined with Figure 7 and Figure 8 Explanation:

[0084] like Figure 7 As shown, in the control loop of a traditional DC-DC voltage conversion circuit, when the load increases from ILoad0 to ILoad1, a voltage drop occurs due to the parasitic resistance of the switches (synchronous transistors) and inductors in the DC-DC voltage conversion circuit. Furthermore, as the load increases, the duty cycle decreases. Since the COT structure of the DC-DC voltage conversion circuit has a constant on-time TON, the duty cycle D increases, and the operating frequency Fsw = D / TON increases accordingly. Figure 7 As shown, when the load increases from ILoad0 to ILoad1, the second on-time signal TON1 corresponding to ILoad1 remains unchanged and is equal to the first on-time signal TON0 corresponding to ILoad0. Therefore, the PWM1 corresponding to ILoad1 changes, and consequently, Fsw1 becomes greater than Fsw0.

[0085] like Figure 8 As shown, when the load increases from ILoad0 to ILoad1, the conduction duration adjustment circuit 100 provided in this application, when the digital circuit module 20 receives the load voltage Vsense detected by the sampling module 10, the digital circuit module 20 outputs the corresponding conduction duration generation voltage VON_TIME according to the corresponding data table. The conduction duration generation module 30 generates a conduction duration signal TON that increases or decreases the conduction time based on the conduction duration generation voltage VON_TIME. After the DC-DC voltage conversion circuit loop stabilizes, the decrease or increase in the loop operating frequency only produces a very small change compared to before the load increase or decrease. That is, as... Figure 8 As shown, when the load current increases from ILoad0 to ILoad1, the second conduction duration TON1 corresponding to ILoad1 changes, while PWM1 corresponding to ILoad1 remains unchanged, thus Fsw1 is approximately equal to Fsw0. Figure 7 and Figure 8 PWM1 and PWM0 are the modulation signals of the input logic control module, and ON_TIME0 and ON_TIME1 represent the specific on-time to generate voltage VON_TIME.

[0086] Similarly, when the DC-DC voltage conversion circuit operates in DCM mode, if a decrease in load is detected, TON is reduced accordingly, thereby reducing the output voltage V. OUT Ripples.

[0087] In some embodiments, the DC-DC voltage conversion circuit operates in DCM mode (Discontinuous Conduction Mode) or CCM mode (Concurrent Conduction Mode). ti In continuous conduction mode, the conduction time of the synchronizing transistor can be adjusted using the methods described above, thereby solving the problem of the operating frequency of the DC-DC voltage conversion circuit changing with the load.

[0088] In some embodiments, the DC-DC voltage conversion circuit may be a BUCK circuit (step-down converter circuit).

[0089] See Figure 9 , Figure 9 This is a schematic diagram of the structure of a first embodiment of the DC-DC voltage conversion chip provided in this application. The DC-DC voltage conversion chip 300 includes an on-time adjustment circuit 100. The on-time adjustment circuit 100 is as described in any embodiment of this application.

[0090] See Figure 10 , Figure 10 This is a schematic diagram of the structure of a second embodiment of the DC-DC voltage conversion chip provided in this application. The DC-DC voltage conversion chip 300 includes a DC-DC voltage conversion circuit 200. The DC-DC voltage conversion circuit 200 is as described in any embodiment of this application.

[0091] See Figure 11 , Figure 11This is a schematic diagram of the third embodiment of the DC-DC voltage conversion chip provided in this application. The DC-DC voltage conversion chip includes a conduction duration adjustment circuit 100, a logic control module, a synchronous transistor Q4, a rectifier transistor Q5, an inductor L, an output capacitor Cout, and voltage divider resistors R2 and R3. The conduction duration adjustment circuit 100 samples the load current at the inductor L and obtains the conduction duration signal TON according to the load current Isense and the technical solution of any of the above embodiments. The logic control module combines the modulation signal PWM and the conduction duration signal TON to obtain a corresponding modulation signal to control the conduction duration of the synchronous transistor Q4, thereby solving the problem that the operating frequency of the DC-DC voltage conversion circuit changes with the load. That is, after the synchronous transistor Q4 is turned on, the input voltage VIN generates the output voltage Vout through the synchronous transistor Q4, the inductor L, and the output capacitor Cout. The modulation signal PWM can be generated based on the feedback voltage FB.

[0092] In summary, the conduction duration adjustment circuit 100, DC-DC voltage conversion circuit, and chip provided in this application utilize the sampling module 10 to acquire the load current Isense in the DC-DC voltage conversion circuit and generate a corresponding load voltage Vsense; and utilize the digital circuit module 20 to receive the load voltage Vsense and generate the conduction duration generation voltage VON_TIME; and utilize the conduction duration generation module 30 to receive the conduction duration generation voltage VON_TIME and the input voltage VIN of the DC-DC voltage conversion circuit, thereby adjusting the conduction duration of the synchronous transistor in the DC-DC voltage conversion circuit using the conduction duration generation voltage VON_TIME and the input voltage VIN, generating a conduction duration signal TON. Thus, the conduction duration signal TON can stabilize the operating frequency of the DC-DC voltage conversion circuit, thereby solving the problem of the DC-DC voltage conversion circuit's operating frequency changing with load variations. That is, the impact of load changes on the DC-DC voltage conversion circuit's operating frequency is reduced, maintaining a stable operating frequency.

[0093] When the embodiments of this application are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) or processor to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0094] The above description is merely an embodiment of this application and does not limit the patent scope of this application. Any equivalent structural or procedural changes made based on the description and drawings of this application, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A conduction time adjustment circuit applied to a DC-DC voltage conversion circuit, characterized by, The application relates to a DC-DC voltage conversion circuit, comprising: a sampling module configured to collect a load current in the DC-DC voltage conversion circuit and generate a corresponding load voltage; a digital circuit module configured to receive the load voltage and generate a conduction duration generation voltage; a conduction duration generation module configured to receive the conduction duration generation voltage and an input voltage of the DC-DC voltage conversion circuit, adjust a conduction duration of a synchronous tube in the DC-DC voltage conversion circuit by using the conduction duration generation voltage and the input voltage, and generate a conduction duration signal; the conduction duration signal is used to stabilize an operating frequency of the DC-DC voltage conversion circuit.

2. The on-duration adjustment circuit of claim 1, wherein, The digital circuit module is configured to obtain a corresponding conduction duration generation voltage by looking up a table according to the load voltage.

3. The on-duration adjustment circuit of claim 2, wherein, The digital circuit module comprises: an analog-to-digital converter configured to receive the load voltage and output a digital signal corresponding to the load voltage; a digital control circuit configured to receive the digital signal and obtain a corresponding conduction duration generation voltage by looking up a table according to the digital signal.

4. The on-duration adjustment circuit of claim 1, wherein, The conduction duration generation module comprises: a current mirror unit configured to receive the input voltage and generate a target voltage; a comparison unit configured to receive the target voltage and the conduction duration generation voltage and generate the conduction duration signal.

5. The on-duration adjustment circuit of claim 4, wherein, The current mirror unit comprises: an error amplifier configured to receive the input voltage and generate an error signal; a transistor configured to receive the error signal; a current mirror, a first end of the current mirror being coupled to a first end of the transistor; a resistive element, a first end of the resistive element being coupled to a second end of the transistor and the error amplifier, and a second end of the resistive element being grounded; a capacitor, a first end of the capacitor being coupled to a second end of the current mirror, and a second end of the capacitor being grounded; wherein a coupling point between the capacitor and the current mirror generates the target voltage.

6. The on-duration adjustment circuit of claim 1, wherein, The conduction duration of the synchronous tube increases with the increase of the load current, and the conduction duration of the synchronous tube decreases with the decrease of the load current.

7. A DC-DC voltage conversion circuit, characterized by The DC-DC voltage conversion circuit comprises the conduction duration adjustment circuit according to any one of claims 1-6.

8. The DC-DC voltage conversion circuit according to claim 7, characterized in that, The DC-DC voltage conversion circuit further comprises a logic control module configured to receive a first modulation signal and the conduction duration signal, generate a second modulation signal, and control the conduction of the synchronous tube in the DC-DC voltage conversion circuit by using the second modulation signal.

9. The DC-DC voltage conversion circuit according to claim 8, characterized in that, The logic control module takes a rising edge moment in a current period in the first modulation signal as a conduction start moment of the second modulation signal, and takes a rising edge moment in a current period in the conduction duration signal as a conduction end moment of the second modulation signal, wherein the rising edge moment in the current period in the conduction duration signal is located after the rising edge moment in the current period in the first modulation signal.

10. A DC-DC voltage conversion chip, characterized by The DC-DC voltage conversion chip comprises the conduction duration adjustment circuit according to any one of claims 1-6 or the DC-DC voltage conversion circuit according to any one of claims 7-9.

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