CN114860017B

CN114860017B - LDO circuit, control method, chip and electronic equipment

Info

Publication number: CN114860017B
Application number: CN202210413816.1A
Authority: CN
Inventors: 殷文杰; 陈敏; 褚晓峰
Original assignee: Chipsea Technologies Shenzhen Co Ltd
Current assignee: Chipsea Technologies Shenzhen Co Ltd
Priority date: 2022-04-15
Filing date: 2022-04-15
Publication date: 2023-09-26
Anticipated expiration: 2042-04-15
Also published as: CN114860017A

Abstract

The application provides an LDO circuit, a control method, a chip and electronic equipment, and belongs to the technical field of electronics. The LDO circuit comprises an output circuit, wherein the output circuit comprises a plurality of power supply branches; the output circuit is configured to turn on at least two of the plurality of power supply branches in turn during power up of the LDO circuit. By adopting the application, the overshoot amplitude of the output voltage in the power-on process of the LDO can be reduced.

Description

LDO circuit, control method, chip and electronic equipment

Technical Field

The present application relates to the field of electronic technologies, and in particular, to an LDO circuit, a control method, a chip, and an electronic device.

Background

LDO (Low-Dropout Regulator, low dropout regulator) circuits are widely used in different electronic devices to provide power for each module therein by virtue of their simple circuit, small size, low power consumption and Low cost.

As the size of the chip is smaller, the power consumption is lower, and the performance requirement on the LDO is higher. Especially in wearable equipment, the stability of the output voltage and the response speed to load transient change in the power-on process of the LDO directly determine the overall performance of the chip.

During power-up of the LDO circuit, an abrupt increase in output voltage produces an overshoot, increasing the risk of the supply voltage being pulled low. Therefore, there is a need to improve the stability of the output voltage of the LDO during power up.

Disclosure of Invention

In order to solve the problems in the prior art, the embodiment of the application provides an LDO circuit, a control method, a chip and electronic equipment, which can reduce the overshoot amplitude of output voltage in the power-on process of the LDO. The technical proposal is as follows:

according to an aspect of the present application, there is provided a low dropout linear regulator LDO circuit, the LDO circuit comprising an output circuit comprising a plurality of supply branches;

the output circuit is configured to turn on at least two of the plurality of power supply branches in turn during power up of the LDO circuit.

Optionally, the LDO circuit further comprises a first control module for generating a first control signal of the power supply branch during power up of the LDO circuit, the first control signal comprising a first off level for turning off the power supply branch and a first on level for turning on the power supply branch.

Optionally, the first control module is configured to sequentially adjust the first control signals of the at least two power supply branches from a first off level to a first on level during power-up of the LDO circuit.

Optionally, the output circuit is further configured to:

when the output voltage of the LDO circuit undershoots, at least one turned-off power supply branch is conducted; and/or

When the output voltage of the LDO circuit overshoots, at least one conducting power supply branch is turned off.

Optionally, the output circuit is further configured to:

when the output voltage of the LDO circuit undershoots, a plurality of turned-off power supply branches are sequentially turned on; and/or

When the output voltage of the LDO circuit overshoots, the plurality of conducted power supply branches are turned off in sequence.

Optionally, the LDO circuit further includes a second control module, where the second control module is configured to generate a second control signal of the power supply branch, where the second control signal includes a first off level for turning off the power supply branch and a first on level for turning on the power supply branch;

the second control module is configured to:

when the output voltage of the LDO circuit undershoots, the second control signal of at least one power supply branch is adjusted from a first turn-off level to a first turn-on level; and/or

When the output voltage of the LDO circuit overshoots, the second control signal of at least one power supply branch is adjusted from a first on level to a first off level.

Optionally, the second control module is configured to:

when the output voltage of the LDO circuit undershoots, the second control signals of the power supply branches are sequentially adjusted from a first turn-off level to a first turn-on level; and/or

When the output voltage of the LDO circuit overshoots, the second control signals of the power supply branches are sequentially adjusted from the first on level to the first off level.

Optionally, the output circuit further comprises at least one discharge branch;

the output circuit is further configured to turn on at least one off discharge leg when an overshoot occurs in an output voltage of the LDO circuit.

Optionally, the output circuit is further configured to sequentially turn on the plurality of turned-off discharge branches when an output voltage of the LDO circuit overshoots.

Optionally, the LDO circuit further includes a third control module, where the third control module is configured to generate a third control signal of the discharge branch, and the third control signal includes a second off level for turning off the discharge branch and a second on level for turning on the discharge branch;

the third control module is configured to adjust a third control signal of at least one discharge leg from a second off level to a second on level when an output voltage of the LDO circuit overshoots.

Optionally, the third control module is configured to sequentially adjust third control signals of the plurality of discharge branches from a second off level to a second on level when an output voltage of the LDO circuit overshoots.

Optionally, the LDO circuit further includes an output voltage detection module;

the output voltage detection module is configured to output an overshoot signal when the output voltage overshoots, wherein the overshoot signal is used for indicating that the output voltage is in an overshoot state; and outputting an undershoot signal when the output voltage undershoots, wherein the undershoot signal is used for indicating that the output voltage is in an undershoot state.

Optionally, the output circuit further includes a switch module group respectively adapted to the power supply branches, the switch module group includes a first switch module and a second switch module, the first switch module is connected in series with the adapted power supply branches, and the second switch module is connected in parallel with the adapted power supply branches;

the first switch module is configured to be in a conducting state when the adaptive power supply branch is conducted, and to be in a cutting-off state when the adaptive power supply branch is cut off;

the second switching module is configured to be in an off state when the adapted power supply branch is on and in an on state when the adapted power supply branch is off.

Optionally, the LDO circuit further comprises an amplifying circuit, a first feedback resistance unit and a second feedback resistance unit, wherein,

the first input end of the amplifying circuit is used for receiving the reference voltage, the second input end of the amplifying circuit is used for receiving the feedback voltage between the first feedback resistance unit and the second feedback resistance unit, and the output end of the amplifying circuit is connected with the first input end of the output circuit;

the second input end of the output circuit is used for receiving the power supply voltage, and the output end of the output circuit is connected with the output end of the LDO circuit;

the first end of the first feedback resistor unit is connected with the output end of the LDO circuit, and the second end of the first feedback resistor unit is connected with the first end of the second feedback resistor unit;

the second end of the second feedback resistor unit is used for grounding.

According to another aspect of the present application, there is provided a control method of an LDO circuit, the LDO circuit including an output circuit including a plurality of power supply branches, the method comprising:

during the power-on period of the LDO circuit, controlling at least two of the power supply branches to be sequentially conducted;

and outputting the output voltage of the LDO circuit based on the output circuit.

According to another aspect of the present application, a chip is provided, including the LDO circuit described above.

According to another aspect of the application, an electronic device is provided, comprising the LDO circuit described above.

In the application, at least two of the power supply branches can be controlled to be sequentially conducted during the power-on period of the LDO circuit, so that the overshoot amplitude of the output voltage is greatly reduced, the power supply voltage of the system can be prevented from being pulled down due to the too large overshoot amplitude of the output voltage of the LDO circuit, and the stability of the system is improved.

Drawings

Further details, features and advantages of the application are disclosed in the following description of exemplary embodiments with reference to the following drawings, in which:

FIG. 1 shows a schematic diagram of an LDO circuit provided in accordance with an exemplary embodiment of the present application;

FIG. 2 shows a schematic diagram of an LDO circuit provided in accordance with an exemplary embodiment of the present application;

FIG. 3 shows a schematic diagram of an LDO circuit provided in accordance with an exemplary embodiment of the present application;

fig. 4 shows a schematic diagram of a power supply branch provided according to an exemplary embodiment of the present application;

FIG. 5 shows a schematic diagram of an LDO circuit for undershoot adjustment provided in accordance with an exemplary embodiment of the present application;

FIG. 6 shows a schematic diagram of an LDO circuit for undershoot adjustment provided in accordance with an exemplary embodiment of the present application;

FIG. 7 shows a schematic diagram of an LDO circuit for overshoot regulation provided in accordance with an exemplary embodiment of the present application;

FIG. 8 shows a schematic diagram of an LDO circuit for overshoot regulation provided in accordance with an exemplary embodiment of the present application;

FIG. 9 shows a schematic diagram of an LDO circuit provided in accordance with an exemplary embodiment of the present application;

FIG. 10 shows a schematic diagram of an LDO circuit provided in accordance with an exemplary embodiment of the present application;

FIG. 11 illustrates a timing relationship diagram provided in accordance with an exemplary embodiment of the present application;

FIG. 12 illustrates a timing relationship diagram provided in accordance with an exemplary embodiment of the present application;

FIG. 13 illustrates a timing relationship diagram provided in accordance with an exemplary embodiment of the present application;

fig. 14 shows a flow chart of a control method of the LDO circuit provided according to an exemplary embodiment of the application.

Detailed Description

Embodiments of the present application will be described in more detail below with reference to the accompanying drawings. While the application is susceptible of embodiment in the drawings, it is to be understood that the application may be embodied in various forms and should not be construed as limited to the embodiments set forth herein, but rather are provided to provide a more thorough and complete understanding of the application. It should be understood that the drawings and embodiments of the application are for illustration purposes only and are not intended to limit the scope of the present application.

The term "including" and variations thereof as used herein are intended to be open-ended, i.e., including, but not limited to. The term "based on" is based at least in part on. The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments. Related definitions of other terms will be given in the description below. It should be noted that the terms "first," "second," and the like herein are merely used for distinguishing between different devices, modules, or units and not for limiting the order or interdependence of the functions performed by such devices, modules, or units.

It should be noted that references to "one", "a plurality" and "a plurality" in this disclosure are intended to be illustrative rather than limiting, and those skilled in the art will appreciate that "one or more" is intended to be construed as "one or more" unless the context clearly indicates otherwise.

The names of messages or information interacted between the devices in the embodiments of the present application are for illustrative purposes only and are not intended to limit the scope of such messages or information.

The embodiment of the application provides an LDO circuit, which can be integrated in a chip or arranged in electronic equipment.

Referring to the schematic of the LDO circuit shown in FIG. 1, the LDO circuit may include an output circuit including a plurality of power supply branches.

In addition, the LDO circuit may further include other circuits for implementing a low dropout linear voltage stabilizing function, and the other circuits may adopt an existing circuit structure, which is not limited in this embodiment. Alternatively, fig. 2 shows a possible LDO circuit, which may comprise the above-mentioned output circuit, an amplifying circuit, a first feedback resistance unit and a second feedback resistance unit, wherein: the first input end of the amplifying circuit is used for receiving the reference voltage, the second input end of the amplifying circuit is used for receiving the feedback voltage between the first feedback resistance unit and the second feedback resistance unit, and the output end of the amplifying circuit is connected with the first input end of the output circuit; the second input end of the output circuit is used for receiving the power supply voltage, and the output end of the output circuit is connected with the output end of the LDO circuit; the first end of the first feedback resistor unit is connected with the output end of the LDO circuit, and the second end of the first feedback resistor unit is connected with the first end of the second feedback resistor unit; the second end of the second feedback resistor unit is grounded.

The configuration of the output circuit will be described below, and the other circuits may be implemented by using existing principles, which are not described in this embodiment. The output circuit may be configured to:

at least two of the plurality of supply branches are turned on in sequence during power-up of the LDO circuit.

In one possible implementation, during power-up of the LDO circuit, any multiple supply branches may be controlled to conduct in sequence to reduce the overshoot amplitude of the LDO output voltage at power-up. Because the amplitude of the output voltage is related to the driving power, when the first power supply branch is conducted in sequence, the instantaneous power conducted each time is smaller, the overshoot amplitude of the output voltage is smaller, compared with the technical scheme that a plurality of power supply branches are conducted simultaneously (namely, a moment provides larger instantaneous power), the overshoot amplitude of the output voltage is greatly reduced, and further, the fact that the power supply voltage of the system is pulled down due to the fact that the overshoot amplitude of the output voltage of the LDO circuit is too large can be avoided, and the stability of the system is improved.

Optionally, referring to the LDO circuit schematic shown in fig. 3, the LDO circuit may further include a first control module, which may be configured to generate a first control signal for the power supply branch during power-up of the LDO circuit, the first control signal including a first off level for turning off the power supply branch and a first on level for turning on the power supply branch, each power supply branch having its corresponding first control signal.

The first control module may be configured to:

during power-up of the LDO circuit, first control signals of at least two power supply branches are sequentially adjusted from a first turn-off level to a first turn-on level.

Wherein the first off level is opposite to the first on level. The first turn-off level and the first turn-on level are adapted to the corresponding power supply branch, for example, when the power supply branch is enabled at a high level, the first turn-on level may be at a high level, and the first turn-off level may be at a low level; when the power supply branch is enabled at a low level, the first on level may be a low level, and the first off level may be a high level. The specific power supply branch and the enable signal thereof are not limited in this embodiment.

In one possible embodiment, the first control signal output by the first control module may be connected to the power supply branch. The first control signal of each power supply branch may be a first off level before the LDO circuit is powered up.

Whether the LDO circuit is powered up or not can be controlled by an enable signal. When the enabling signal is enabled, the first control module can adjust the first control signal of the power supply branch conducted in the power-on period from a first turn-off level to a first turn-on level through control logic in the preset power-on period. Furthermore, the first power supply branch may be turned on when the first control signal jumps from the first off level to the first on level, to provide a base voltage for the output voltage.

Wherein each first control signal transitions from a first off level to a first on level at a different time.

In one possible embodiment, the first control module may adjust the first control signals of any number of power supply branches from the first off level to the first on level at different times, respectively. Furthermore, any plurality of power supply branches can be controlled to be conducted at different moments, namely to be conducted sequentially.

Optionally, for each time point when the first control signal jumps from the first off level to the first on level, the time interval between every two adjacent time points is the same. On the basis, the overshoot amplitude of the output voltage of the LDO circuit during the power-on period can be stably regulated, and the stability of the system is further improved.

Optionally, referring to the schematic diagram of the power supply branch shown in fig. 4, the output circuit may further include a switch module group respectively adapted to the power supply branch, where the switch module group includes a first switch module and a second switch module, the first switch module is connected in series with the adapted power supply branch, and the second switch module is connected in parallel with the adapted power supply branch.

The first switching module may be configured to be in an on state when the adapted power supply branch is on and to be in an off state when the adapted power supply branch is off;

The second switching module may be configured to be in an off state when the adapted power supply branch is on and in an on state when the adapted power supply branch is off.

Alternatively, when the first switching module is controlled based on the first control signal of the adapted power supply branch, the second switching module may be controlled based on a signal opposite to the first control signal. That is, the first switching module may be configured to be turned on when the first control signal of the adapted power supply branch is a first on level and turned off when the first control signal of the adapted power supply branch is a first off level; the second switching module may be configured to be turned on when a signal opposite to the first control signal of the adapted power supply branch is a first on level and turned off when a signal opposite to the first control signal of the adapted power supply branch is a first off level.

On the basis, when the power supply branch is turned off, the turned-off first switch module can be connected in parallel to the output end of the LDO circuit, which is equivalent to connecting a capacitor in parallel to the output end of the LDO circuit, so that the function of stabilizing the output voltage can be achieved, and the stability of the output voltage of the LDO circuit is further improved.

After the output voltage is stable, the output voltage of the LDO will be suddenly changed along with the change of the load current, and overshoot or undershoot is generated. Therefore, the present application also provides an LDO circuit that can achieve a fast response to overshoot or undershoot.

Optionally, referring to the LDO circuit schematic shown in fig. 5, the output circuit may be further configured to:

In one possible implementation, during power up of the LDO circuit, part of the supply branches may be turned on, the remaining supply branches remain turned off, and a fast response to undershoot is achieved by the turned-off supply branches. When the load current of the LDO circuit is suddenly changed, the output voltage of the LDO circuit is suddenly changed to generate undershoot. At this time, the power supply branch in the off state can be turned on, the voltage provided for the output voltage is increased, and the output voltage of the LDO circuit is promoted to be recovered to a stable value. It should be noted that the power supply branch that is turned on may not be turned off in a steady state. For example, power supply branch a is turned on in response to a first undershoot, power supply branch B remains off, power supply branch a is not turned off after settling, and power supply branch B is turned on in response to a second undershoot.

Or when the load current of the LDO circuit suddenly changes, the output voltage of the LDO circuit suddenly changes to generate overshoot when the load current is switched from heavy load to light load. At this time, the power supply branch in the on state can be turned off, the voltage provided for the output voltage is reduced, and the output voltage of the LDO circuit is promoted to be recovered to a stable value.

Of course, the output circuit may also be configured to switch on at least one of the turned-off supply branches when an undershoot occurs in the output voltage of the LDO circuit, and to switch off at least one of the turned-on supply branches when an overshoot occurs in the output voltage of the LDO circuit. I.e. a fast response to undershoot or overshoot can be achieved by controlling the supply branch.

Optionally, when the output circuit includes a plurality of power supply branches for fast response, the output circuit may be further configured to:

In a possible implementation manner, in the case that a plurality of off power supply branches exist, when the output voltage generates undershoot, any plurality of power supply branches can be controlled to be sequentially conducted, so that quick response to the undershoot is realized. The multiple power supply branches that are turned on and the multiple power supply branches that are turned off that exist before being turned on may be the same, or may be any multiple of the power supply branches that are turned off. Because switch on a plurality of power supply branch circuits simultaneously, be equivalent to once switch on the switching tube of size several times, required time is long, the consumption is big, consequently compare in the technical scheme of switch on a plurality of power supply branch circuits simultaneously, the consuming time of switching on power supply branch circuit in proper order reduces, can reduce transient power consumption.

Under the condition that a plurality of conducting power supply branches exist, when the output voltage generates overshoot, any plurality of conducting power supply branches can be controlled to be turned off in sequence, and the rapid response to the overshoot is realized. Because the power supply branches are turned off simultaneously, which is equivalent to turning off the switching tube with the size of several times at one time, the time required is long and the power consumption is large, compared with the technical scheme of turning off the power supply branches simultaneously, the time consumption of turning off the power supply branches in sequence is reduced, and the transient power consumption can be reduced.

It should be noted that, by increasing or decreasing the number of power supply branches, the overshoot voltage of the LDO can be pulled down at the moment of switching off the power supply branches, or the undershoot voltage of the LDO can be pulled up at the moment of switching on the power supply branches, so as to alleviate the transient voltage overshoot or undershoot caused by load variation. After one or more power supply branches are turned off/on, the output voltage of the LDO circuit is stabilized to a preset reference voltage value again due to the action of the operational amplifier feedback loop in the LDO circuit, and is not affected by the number of turned-on power supply branches.

In one possible embodiment, the plurality of power supply branches in the output circuit includes at least one power supply branch operable to respond to overshoot and at least one normally-on power supply branch. The plurality of supply branches available for responding to the overshoot means that the basic function of the LDO circuit to output a regulated voltage is not affected when the at least one supply branch available for responding to the overshoot is all turned off. For example, when the LDO circuit is in operation, after one or more of the supply legs available to respond to the overshoot are turned off, the LDO circuit may still maintain the voltage output through the at least one normally-on supply leg, so as not to cause the LDO output voltage to be 0. In this example, the number of normally-on supply branches may be set according to the required LDO minimum load capability such that the at least one normally-on supply branch meets the minimum load requirement when all supply branches available to respond to overshoot are off. It should be noted that, the at least one normally-on power supply branch is not limited to a fixed power supply branch, and the number of power supply branches conducted in the output circuit is greater than or equal to the number set in the foregoing, for example, when the number of normally-on power supply branches is set to 1, it may be ensured that any 1 or more power supply branches in the output branch are conducted, and the at least one normally-on power supply branch is not limited to a certain fixed power supply branch.

Further optionally, a first number of supply branches that are turned on in response to an undershoot may be determined based on a magnitude of the undershoot voltage and/or a second number of supply branches that are turned off in response to an overshoot may be determined based on a magnitude of the overshoot voltage. The output circuit may be further configured to: when the output voltage of the LDO circuit undershoots, the first number of turned-off power supply branches are turned on; and/or, when the output voltage of the LDO circuit overshoots, the second number of on power supply branches are turned off. On the basis, the adaptability of the number of power supply branches for quick response and the overshoot amplitude or undershoot amplitude can be improved, and the accuracy of transient response is improved.

Optionally, referring to the LDO circuit schematic shown in fig. 6, the LDO circuit may further include a second control module, which may be configured to generate a second control signal for the power supply branches, the second control signal including a first off level for turning off the power supply branches and a first on level for turning on the power supply branches, each power supply branch having its corresponding second control signal.

The second control module may be configured to:

When the output voltage of the LDO circuit overshoots, the second control signal of at least one power supply branch is adjusted from the first on level to the first off level.

In one possible embodiment, the second control signal output by the second control module can be connected to a power supply branch for a fast response.

The second control signal for the power supply branch responsive to the undershoot may be a first off level prior to the responsive undershoot to control the corresponding power supply branch to be in an off state. When the output voltage generates undershoot, the second control module can determine specific control of the power supply branch circuit through first preset logic, and adjust a second control signal of the power supply branch circuit responding to the undershoot from a first turn-off level to a first turn-on level. The power supply branch is conducted when the second control signal jumps from the first turn-off level to the first turn-on level, so that quick response to undershoot is realized.

The second control signal for the power supply branch responsive to the overshoot may be a first conduction level prior to the response of the overshoot, controlling the corresponding power supply branch to be in a conductive state. When the output voltage generates overshoot, the second control module can determine specific control of the power supply branch through second preset logic, and adjust a second control signal of the power supply branch for responding to the overshoot from a first on level to a first off level. The power supply branch is turned off when the second control signal jumps from the on level to the off level, so that the quick response to the overshoot is realized. Optionally, the second control module may be further configured to, corresponding to a case of controlling the plurality of power supply branches to achieve a fast response:

In one possible embodiment, the second control module may adjust the plurality of second control signals from the first off level to the first on level at different times, respectively, in response to the undershoot. Furthermore, the plurality of power supply branches which are turned off can be controlled to be turned on at different moments, i.e. turned on sequentially.

Similarly, the second control module may adjust the plurality of second control signals from the first on level to the first off level at different times, respectively, in response to the overshoot. Furthermore, the plurality of conducting power supply branches can be controlled to be turned off at different moments, namely to be turned on sequentially. Optionally, in a response process, for each time point when the second control signal jumps from the on level to the off level, the time interval between every two adjacent time points is the same, or for each time point when the second control signal jumps from the off level to the on level, the time interval between every two adjacent time points is the same. On this basis, the stability of the output voltage can be ensured.

Optionally, the first control module and the second control module may be the same or different. When the first control module and the second control module are the same, the first control signal and the second control signal of one power supply branch may also be the same control signal. When the first control module and the second control module are different, during the power-on period of the LDO circuit, the first control signal output by the first control module can be selected to control each power supply branch; thereafter, the second control signal output by the second control module may be selected to control each power supply branch.

Optionally, the power supply branch for fast response may also have the above-mentioned switch module group adapted in the same manner as the power supply branch shown in fig. 4, and will not be described here again.

Optionally, referring to the LDO circuit schematic shown in fig. 7, the output circuit may further include at least one discharge branch. The current direction of the discharging branch circuit is different from the current direction of the power supply branch circuit. For example, the current of the supply branch flows to the load, while the current of the discharge branch flows to ground. The discharge branch may achieve a fast response to the overshoot by discharging. The output circuit may be further configured to:

When the output voltage of the LDO circuit overshoots, at least one off discharge branch is conducted.

In one possible implementation, after the LDO circuit is powered up, the initial state of the discharge branch may be an off state, and a fast response to the overshoot is achieved by the off discharge branch. When the load current of the LDO circuit suddenly changes, the output voltage of the LDO circuit suddenly changes to generate overshoot when the load current is switched from heavy load to light load. At this time, the discharge branch in the off state can be turned on, so that the discharge is accelerated, and the output voltage of the LDO circuit is promoted to be recovered to a stable value. It should be noted that the already switched discharge branch may not be switched off in a steady state. For example, discharge leg a is turned on in response to a first overshoot, discharge leg B remains turned off, discharge leg a is not turned off after settling, and discharge leg B is turned on in response to a second overshoot.

The number of discharge branches that are turned on in response to an overshoot and the number of supply branches that are turned on in response to an undershoot may be the same or different. For example, 3 discharge branches may be turned on in response to an overshoot, and 3 supply branches may be turned on in response to an undershoot, or 2 supply branches may be turned on.

Optionally, when the output circuit includes a plurality of discharge branches for responding to the overshoot, the output circuit may be configured to:

when the output voltage of the LDO circuit overshoots, a plurality of turned-off discharging branches are turned on in sequence.

In a possible implementation manner, in the case that a plurality of discharge branches exist, when the output voltage generates overshoot, any plurality of discharge branches can be controlled to be sequentially conducted, so that quick response to the overshoot is realized. The plurality of on-state discharge branches and the plurality of off-state discharge branches existing before the on-state discharge branches may be the same, or any plurality of off-state discharge branches may be used. Because a plurality of discharge branches are conducted simultaneously, which is equivalent to the switching tube with the once conducted size of several times, the required time is long and the power consumption is large, compared with the technical scheme of conducting a plurality of discharge branches simultaneously, the time consumption of conducting the discharge branches sequentially is reduced, and the transient power consumption can be reduced.

It should be noted that, by increasing the number of the discharge branches, the overshoot voltage of the LDO can be reduced at the instant of switching on the discharge branches. After one or more discharge branches are turned on, the output voltage of the LDO circuit is stabilized to a preset reference voltage value again due to the action of an operational amplifier feedback loop in the LDO circuit, and the output voltage is not influenced by the conduction number of the discharge branches.

Further optionally, a third number of discharge branches to be turned on in response to the overshoot is determined according to the magnitude of the overshoot voltage. The output circuit may be further configured to: when the output voltage of the LDO circuit overshoots, the third number of discharge branches are conducted. On the basis, the number of discharge branches for responding to the overshoot and the adaptability of the overshoot amplitude can be improved, and the accuracy of transient response can be improved.

Optionally, referring to the LDO circuit schematic shown in fig. 8, the LDO circuit may further include a third control module that may be used to generate a third control signal for the discharge legs, the third control signal including a second off level for turning off the discharge legs and a second on level for turning on the discharge legs, each discharge leg having its corresponding third control signal. The third control module may be the same as the first control module, or may be the same as the second control module, or may be different from the first control module and the second control module.

The third control module may be configured to:

when the output voltage of the LDO circuit overshoots, the third control signal of at least one discharging branch is adjusted from the second off level to the second on level.

Wherein the second off level is opposite to the second on level. The second turn-off level and the second turn-on level are adapted to the corresponding discharge branch, for example, when the discharge branch is enabled at a high level, the second turn-on level may be at a high level, and the second turn-off level may be at a low level; when the discharge branch is enabled at a low level, the second on level may be at a low level, and the second off level may be at a high level. The specific discharge branch and the enable signal thereof are not limited in this embodiment.

In one possible embodiment, the third control signal output by the third control module may be connected to the corresponding discharge branch. The third control signal for the discharge leg responsive to the overshoot may be a second off level prior to the responsive overshoot, controlling the corresponding discharge leg to be in an off state.

When the output voltage generates the overshoot, the third control module can determine specific control of the discharge branch through third preset logic, and adjust a third control signal of the discharge branch for responding to the overshoot from a second off level to a second on level. The discharging branch is turned off when the third control signal jumps from the second turn-off level to the second turn-on level, so that the rapid response to the overshoot is realized.

Optionally, the third control module may be configured to, corresponding to a case where the plurality of discharge branches are controlled to achieve a fast response:

when the output voltage of the LDO circuit overshoots, the third control signals of the discharge branches are sequentially adjusted from the second turn-off level to the second turn-on level.

In one possible embodiment, the third control module may adjust the plurality of third control signals from the second off level to the second on level at different times, respectively, in response to the overshoot. Furthermore, a plurality of off discharge branches can be controlled to be turned on at different moments, i.e. turned on sequentially.

Optionally, in a response process, for each time point when the third control signal jumps from the second off level to the second on level, the time interval between every two adjacent time points is the same. On this basis, the stability of the output voltage can be ensured.

Optionally, referring to the LDO circuit schematic shown in fig. 9, the LDO circuit may further include an output voltage detection module, which may detect an overshoot or an undershoot of the output voltage of the LDO circuit.

The output voltage detection module may be configured to output an overshoot signal when an overshoot occurs in the output voltage; and outputting an undershoot signal when the undershoot occurs in the output voltage.

Wherein the overshoot signal may be used to indicate that the output voltage is in an overshoot state and the undershoot signal may be used to indicate that the output voltage is in an undershoot state. The overshoot signal is opposite to the undershoot signal. For example, the overshoot signal may be a negative pulse signal, the undershoot signal may be a positive pulse signal, and vice versa. The specific forms of the overshoot signal and the undershoot signal are not limited in this embodiment.

In one possible implementation, an input of the output voltage detection module may be connected to an output of the LDO circuit for detecting whether the output voltage of the LDO circuit is smaller than a first threshold value or larger than a second threshold value. When the output voltage is less than the first threshold, indicating that the output voltage generates an undershoot, the output voltage detection module may generate an undershoot signal. When the output voltage is greater than the second threshold, indicating an output voltage generation process, at which time the output voltage detection module may generate an overshoot signal.

Optionally, the second control module and the third control module may be the same, that is, belong to the same control module; or may be different, i.e. belong to different control modules.

For the case of belonging to the same control module, the undershoot signal and the overshoot signal output by the output voltage detection module can be connected to the control module. Further, when the undershoot signal is received, the control module may determine a specific control of the power supply branch through the first preset logic, and adjust the second control signal of the power supply branch for responding to the undershoot from the first off level to the first on level. When the overshoot signal is received, the control module can determine specific control on the power supply branch through the second preset logic, and adjust a second control signal of the power supply branch for responding to the overshoot from a first on level to a first off level; and/or determining specific control of the discharge branch through the third preset logic, and adjusting a third control signal of the discharge branch for responding to the overshoot from a second off level to a second on level.

For the condition of different control modules, when the power supply branch is adopted to realize the rapid response to the undershoot, the undershoot signal output by the output voltage detection module can be connected into the second control module; when the fast response of the power supply branch to the overshoot is also adopted, the overshoot signal can be connected into the second control module; when a discharge branch is used to achieve a fast response to the overshoot, the overshoot signal may be coupled to the third control module. The processing of the second control module and the third control module is the same as that described above, and will not be repeated.

Further alternatively, corresponding to the above case of determining the number of branches according to the overshoot amplitude or the undershoot amplitude, the output voltage detection module may be further configured to:

when the output voltage is smaller than a first threshold value, determining a first number of power supply branches which are conducted in response to undershoot according to the current output voltage, and transmitting the first number of information to a second control module;

when the output voltage is greater than a second threshold value, determining a second number of power supply branches turned off in response to the overshoot according to the magnitude of the current output voltage, and transmitting information of the second number to a second control module; and/or determining a third number of discharge branches turned on in response to the overshoot according to the magnitude of the current output voltage, and transmitting the third number of information to a third control module.

When the output voltage is smaller than the first threshold value, the current output voltage may be referred to as an undershoot voltage; when the output voltage is greater than the second threshold, the current output voltage may be referred to as an overshoot voltage. The larger the overshoot amplitude of the undershoot voltage is, the larger the first quantity is; conversely, the smaller the undershoot magnitude, the smaller the above-mentioned first number. Similarly, when the power supply branch or the discharge branch is adopted to realize the quick response to the overshoot, the larger the overshoot amplitude of the overshoot voltage is, the larger the second quantity or the third quantity is; conversely, the smaller the overshoot amplitude, the smaller the above-mentioned second number or third number. Or when the power supply branch and the discharge branch are adopted to jointly realize the quick response to the overshoot, the larger the overshoot amplitude of the overshoot voltage is, the larger the sum of the second quantity and the third quantity is; conversely, the smaller the overshoot amplitude, the smaller the sum of the second number and the third number.

In one possible implementation manner, a correspondence between the magnitude of the undershoot voltage and the number of power supply branches that are turned on may be preset, and further, when the output voltage is smaller than the first threshold value, the first number of power supply branches that need to be turned on for the current undershoot voltage may be determined according to the correspondence.

In another possible embodiment, the number of power supply branches that are determined to be turned on in response to the undershoot according to the magnitude of the present output voltage may specifically refer to: determining the difference value between the current output voltage and a preset reference voltage according to the current output voltage; based on the magnitude of the difference, a first number of power supply branches that are turned on in response to the undershoot is determined. Similarly, a correspondence between the magnitude of the difference and the number of branches to be responded (which may be referred to as a first number at this time) may be preset, and then, when the output voltage is smaller than the first threshold, the first number of power supply branches that need to be turned on for the current undershoot voltage may be determined according to the correspondence.

When the power supply branch or the discharge branch is adopted to realize the quick response to the overshoot, the implementation of determining the second number or the third number is the same as the above, and will not be repeated here.

When the power supply branch and the discharge branch are adopted to jointly realize quick response to the overshoot, in one possible implementation manner, a corresponding relation between the magnitude of the overshoot voltage and the number of branches to be responded can be preset, and when the output voltage is greater than a second threshold value, the number of branches required to be responded by the current overshoot voltage can be determined according to the corresponding relation. Further, the second number of power supply branches to be turned off and the third number of discharge branches to be turned on may be determined according to the number of branches, respectively.

In another possible implementation manner, the magnitude of the difference between the current output voltage and the preset reference voltage may be determined according to the magnitude of the current output voltage; and determining the number of the branches to be responded according to the difference value. Similarly, a correspondence between the magnitude of the difference and the number of branches to be responded (which may refer to the sum of the second number and the third number at this time) may be preset, and further, when the output voltage is greater than the second threshold, the number of branches to be responded in the current overshoot voltage may be determined according to the correspondence. Further, the second number of power supply branches to be turned off and the third number of discharge branches to be turned on may be determined according to the number of branches, respectively.

Alternatively, the correspondence between the magnitude of the difference value and the number of branches to be responded may be the same correspondence, and on this basis, when the same correspondence is adopted based on the deviation between the voltage amplitude and the reference voltage, the complexity of the circuit logic may be reduced, and the processing efficiency may be improved.

Correspondingly, when the power branch is employed to respond to the undershoot, the second control module may be configured to: when the undershoot signal and the first quantity of information are received, determining a power supply branch to be conducted according to the second quantity and the current power supply branch, and adjusting a second control signal of the power supply branch to be conducted from a first turn-off level to a first turn-on level.

In one possible implementation manner, when the undershoot signal and the first number of information are received, the second control module may determine, through the first preset logic, a power supply branch to be turned on from the power supply branches that are currently turned off, and the number of power supply branches to be turned on may be less than or equal to the first number. For example, when the current power supply branches available for responding to undershoot are greater than or equal to the first number, any first number of power supply branches can be used as power supply branches to be conducted, and at this time, the number of power supply branches to be conducted is equal to the first number; when the current power supply branches available for responding to undershoot are smaller than the first number, all the power supply branches to be turned off can be used as power supply branches to be turned on, and at this time, the number of the power supply branches to be turned on can be smaller than the first number.

When the power supply branch is employed to respond to the overshoot, the second control module may be configured to: when the overshoot signal and the second quantity of information are received, determining a power supply branch to be turned off according to the second quantity and the current power supply branch, and adjusting a second control signal of the power supply branch to be turned off from a first on level to a first off level.

In one possible implementation manner, when the overshoot signal and the second number of information are received, the second control module may determine, through the second preset logic, a power supply branch to be turned off from the currently turned-on power supply branches, and the number of power supply branches to be turned off may be less than or equal to the second number. For example, when the current power supply branch available for responding to the overshoot is greater than or equal to the second number, any second number of power supply branches may be taken as the power supply branch to be turned off, where the number of power supply branches to be turned off is equal to the second number; when the current power supply branches available for responding to the overshoot are smaller than the second number, the remaining power supply branches that are turned on can be turned off on the basis that the number of power supply branches that are turned on in the output circuit is equal to the set normal-on number, and at this time, the number of power supply branches to be turned off can be smaller than the second number.

When the discharge leg is employed to respond to the overshoot, the third control module may be configured to: when the overshoot signal and the third quantity of information are received, determining a discharge branch to be conducted according to the third quantity and the discharge branch which is turned off currently, and adjusting a third control signal of the discharge branch to be conducted from a second turn-off level to a second turn-on level.

In one possible implementation manner, when the overshoot signal and the third number of information are received, the third control module may determine, through a third preset logic, a discharge branch to be turned on from the discharge branches that are currently turned off, and the number of discharge branches to be turned on may be less than or equal to the third number. For example, when the number of discharge branches currently available for responding to the overshoot is greater than or equal to the third number, any third number of discharge branches may be used as the discharge branches to be turned on, where the number of discharge branches to be turned on is equal to the third number; when the current available discharge branches for responding to the overshoot are smaller than the third number, all the discharge branches to be turned off may be regarded as discharge branches to be turned on, and at this time, the number of discharge branches to be turned on may be smaller than the third number.

The present embodiment does not limit the policy adopted to determine a specific branch among the branches available for response, and for example, a random determination manner may be adopted, or a sequential determination manner may also be adopted.

The above describes embodiments in which the LDO circuit achieves a fast response to undershoot or overshoot after a single power up. When the LDO circuit is powered on each time, the power supply branch circuit and the discharge branch circuit can be reset, and each branch circuit is restored to an initial state after the reset, so that quick response is realized through the embodiment after the power is powered on each time. The initial state of each branch circuit can be preset, and when the power is on each time, the initial state of each branch circuit in the output circuit can be at least two power supply branch circuits on and all discharge branch circuits off, and the specific setting of the initial state of each branch circuit is not limited in this embodiment.

The embodiment of the application has the following beneficial effects:

(1) During the power-on period of the LDO circuit, at least two of the power supply branches can be controlled to be sequentially conducted, the overshoot amplitude of the output voltage is greatly reduced, the phenomenon that the power supply voltage of the system is pulled down due to the fact that the overshoot amplitude of the output voltage of the LDO circuit is too large can be avoided, and the stability of the system is improved.

(2) The LDO circuit may achieve a fast response to undershoot or overshoot through the supply branch and/or the discharge branch. When the output voltage generates undershoot, the power supply branch circuit is conducted to realize quick response to the undershoot, and when the output voltage generates overshoot, the power supply branch circuit is turned off and/or the discharge branch circuit is conducted to realize quick response to the overshoot.

(3) And when the rapid response to undershoot or overshoot is realized, the multiple branches are controlled to be sequentially turned on or turned off, so that the transient power consumption of the LDO circuit can be reduced.

The LDO circuit provided by the present application will be described with reference to a specific circuit structure, but is not limited to the specific circuit structure provided by the present embodiment. The LDO circuit provided in this embodiment may implement staged start in the power-up process, and transient response adjustment of 1bit (bit) or multiple bits, that is, control one or more power supply branches to implement transient response.

Referring to the LDO circuit schematic shown in fig. 10, the LDO circuit may include an error amplifier AMP, an output circuit, a load resistor capacitor, a feedback resistor string, a power-up stage start-up control circuit, an output voltage detection circuit, and a transient response switch regulation circuit. The output circuit may include a plurality of power supply branches and a plurality of discharge branches, wherein the plurality of power supply branches may be divided into a power-on start branch group and a undershoot adjustment branch group, and the plurality of discharge branches may be referred to as an overshoot adjustment branch group.

The power-on starting branch group corresponds to a power supply branch which is conducted in the power-on period and comprises 3 MOS tubes (field effect tubes) MP1, MP2 and MP3 which are connected in parallel, each MOS tube is matched with two switches, one switch is connected in series with the MOS tube, the other switch is connected in parallel with the MOS tube to form 3 power supply branches, the serial switches (corresponding to the first switch modules) are controlled based on S1P, S2P, S P signals (corresponding to the first control signals) respectively, and the parallel switches (corresponding to the second switch modules) are controlled based on S1N, S2N, S N signals (corresponding to signals opposite to the first control signals) respectively.

The undershoot adjusting branch group corresponds to the power supply branch for responding to undershoot, and comprises 2 MOS (metal oxide semiconductor) tubes MP4 and MP5 which are connected in parallel, wherein each MOS tube is matched with two switches, one switch is connected with the MOS tube in series, the other switch is connected with the MOS tube in parallel to form 2 power supply branches, the switches (corresponding to the first switch modules) connected in series are controlled based on S4P, S P signals (corresponding to the second control signals) respectively, and the switches (corresponding to the second switch modules) connected in parallel are controlled based on S4N, S N signals (corresponding to signals opposite to the second control signals) respectively.

The overshoot regulation branch group corresponds to the above-mentioned discharge branch for responding to the overshoot, and includes 2 MOS transistors MN6 and MN7 connected in parallel to form 2 discharge branches, and is controlled based on the S6P, S P signal (corresponding to the above-mentioned third control signal) respectively.

The first ends of the MOS tubes MP1, MP2, MP3, MP4 and MP5 are all used for accessing the power supply voltage VDD, the second ends are all connected with the output end of the LDO circuit, and the third ends (i.e. the control ends) are all connected with the output end of the error amplifier AMP. The first ends of the MOS tubes MN6 and MN7 are connected with the output end of the LDO circuit, the second ends are grounded, and the third ends (namely the control ends) are respectively connected with S6P, S P signals.

The load resistance capacitance includes a load resistance ESR and a load capacitance Cload. One end of the load resistor ESR is connected with the output end of the LDO circuit, and the other end of the load resistor ESR is connected with the load capacitor Cload. One end of the load capacitor Cload is connected with the load resistor ESR, and the other end is grounded.

The feedback resistor string comprises resistors R1 and R2 which are connected in series and respectively correspond to the first feedback resistor unit and the second feedback resistor unit. One end of the resistor R1 is connected with the output end of the LDO circuit, and the other end of the resistor R1 is connected with the resistor R2. One end of the resistor R2 is connected with the resistor R1, and the other end is grounded.

The error amplifier AMP corresponds to the amplifying circuit, the inverting input terminal is used for accessing the reference voltage VREF, the non-inverting input terminal is used for accessing the feedback voltage VFB, and the output terminal is respectively connected with the control terminals of the MOS transistors MP1, MP2, MP3, MP4, MP5, MP6, MP 7. The feedback voltage VFB is a voltage between the resistors R1 and R2. The error amplifier AMP is driven based on the enable signal ENN, and operates normally when the enable signal ENN is enabled.

The power-on stage start-up control circuit corresponds to the first control module and is configured to receive the enable signal ENN and the bandgap reference circuit signal bgr_ok, and output the S1P, S2P, S3P, S1N, S2N, S3N signal. The S1N signal is a signal obtained by passing S1P through an inverter, the S2N signal is a signal obtained by passing S2P through an inverter, and the S3N signal is a signal obtained by passing S3P through an inverter.

The output voltage detection circuit corresponds to the output voltage detection module and is controlled based on the S1P, S2P, S P signal, the input end of the output voltage detection circuit is connected with the output end of the LDO circuit, and the output end of the output voltage detection circuit is connected with the transient response switch regulation circuit.

The transient response switch regulation circuit corresponds to the condition that the second control module and the third control module belong to the same control module, the input end of the transient response switch regulation circuit is connected with the output voltage detection circuit, and the signal S4P, S5P, S6P, S7P, S4N, S5N is output. The S4N signal is a signal obtained by passing S4P through an inverter, and the S5N signal is a signal obtained by passing S5P through an inverter.

The working principle of the LDO circuit for implementing multi-stage start will be described with reference to a timing diagram shown in fig. 11.

When the enable signal ENN transitions from a high level to a low level, the enable signal ENN enables and the LDO circuit begins to power up. At this time, the bgr_ok signal may transition from a low level to a high level accordingly. The power-on hierarchical start control circuit sequentially delays a BGR_OK signal (a jump signal from low to high) by t1 under the control of an enable signal ENN to obtain S1P, S P and S3P signals: the time when the S1P signal transitions from low to high is the same as the bgr_ok signal (a certain time interval may be present), the time when the S2P signal transitions from low to high is delayed by a time t1 from the S1P signal, and the time when the S3P signal transitions from low to high is delayed by a time t1 from the S2P signal.

In fig. 11, the solid line in the schematic diagram of the output voltage ldo_vout indicates the voltage variation of the output voltage ldo_vout when MP1, MP2, and MP3 are turned on in sequence, and the dotted line indicates the voltage variation of the output voltage ldo_vout when MP1, MP2, and MP3 are turned on simultaneously. It can be seen that under the control of the signals S1P, S2P, S3P, S1N, S2N, S3N, MP1, MP2 and MP3 are respectively connected to the circuits, so that the overshoot amplitude of the output voltage ldo_vout of the LDO circuit is greatly reduced compared with that of the output voltage ldo_vout when the circuits are simultaneously turned on, thereby avoiding the power supply voltage from being pulled down due to too large overshoot of the output voltage ldo_vout of the LDO, and improving the stability of the system.

The working principle of the LDO circuit for implementing 1bit transient response adjustment will be described with reference to the timing diagram shown in fig. 12.

After the output voltage ldo_vout stabilizes, when the load current i_load changes suddenly, the output voltage of the LDO changes suddenly from the light load Imin to the heavy load Imax, and undershoot occurs. At this time, the output voltage detection circuit outputs a positive pulse signal (corresponding to the above-described undershoot signal) under the control of the S1P, S P and S3P signals. The positive pulse signal acts on the transient response switch regulating circuit, so that the transient response switch regulating circuit generates a positive pulse signal S4P and a negative pulse signal S4N, or the positive pulse signal S5P and the negative pulse signal S5N, and controls the MOS tube MP4 or MP5 in the undershoot regulating branch group to be conducted (namely, a 1bit control signal and 1 power supply branch) so as to increase the power supply branch, and further, the output voltage of the LDO is quickly recovered to a stable value.

When the load current i_load suddenly changes, the output voltage of the LDO is suddenly changed from the heavy load Imax to the light load Imin, and overshoot is generated. At this time, the output voltage detection circuit outputs a negative pulse signal (corresponding to the above-described overshoot signal) under the control of the S1P, S P and S3P signals. The negative pulse signal acts on the transient response switch regulating circuit, so that the transient response switch regulating circuit generates a negative pulse signal S6P or S7P (namely a control signal of 1 bit) to control the MOS tube MP6 or MP7 in the overshoot regulation branch group to be conducted, thereby increasing the discharge branch and further enabling the output voltage of the LDO to be quickly recovered to a stable value.

In fig. 12, the solid line in the schematic diagram of the output voltage ldo_vout represents the voltage variation of the output voltage ldo_vout when the transient response adjustment is performed by the present application, and the dotted line represents the voltage variation of the output voltage ldo_vout when the transient response adjustment is not performed. It can be seen that the time for the output voltage LDO_VOUT to recover to a stable value is shortened when the application is adopted, and the transient response performance of the LDO circuit is improved.

The operation principle of the LDO circuit for implementing multi-bit transient response adjustment will be described with reference to the timing diagram shown in fig. 13.

After the output voltage ldo_vout stabilizes, when the load current i_load changes suddenly, the output voltage of the LDO changes suddenly from the light load Imin to the heavy load Imax, and undershoot occurs. At this time, the output voltage detection circuit controls the next positive pulse signal (corresponding to the above-described undershoot signal) under the control of the S1P, S P and S3P signals. The positive pulse signal acts on the transient response switch regulating circuit, so that the transient response switch regulating circuit generates two positive pulse signals S4P and S5P (namely 2bit control signals) according to different threshold voltages, and two corresponding negative pulse signals S4N and S5N, so that MOS (metal oxide semiconductor) tubes MP4 and MP5 in the undershoot regulating branch group are controlled to be conducted step by step, a power supply branch is increased, and the output voltage of the LDO is quickly restored to a stable value.

When the load current i_load suddenly changes, the output voltage of the LDO is suddenly changed from the heavy load Imax to the light load Imin, and overshoot is generated. At this time, the output voltage detection circuit outputs a negative pulse signal (corresponding to the above-described overshoot signal) under the control of the S1P, S P and S3P signals. The undershoot signal acts on the transient response switch regulating circuit, so that the transient response switch regulating circuit generates two undershoot signals S6P and S7P (namely a 2bit control signal) according to different threshold voltages, and controls MOS transistors MP6 and MP7 in the overshoot regulation branch group to conduct step by step, thereby increasing a discharge branch and further enabling the output voltage of the LDO to quickly recover to a stable value.

In fig. 13, the solid line in the schematic diagram of the output voltage ldo_vout represents the voltage variation of the output voltage ldo_vout when the transient response adjustment is performed by the stepwise conduction, and the dotted line represents the voltage variation of the output voltage ldo_vout when the transient response adjustment is not performed by the stepwise conduction. It can be seen that when the step-by-step conduction is adopted, the overshoot or undershoot amplitude of the output voltage LDO_VOUT can be finely regulated in multiple bits, so that the LDO has the effect of quick response to the output voltage of the LDO and can reduce transient power consumption.

In this embodiment, a group of 2 MOS transistors is taken as an example, and the corresponding control signal may be 2 bits. When a group includes more than 2 MOS transistors, the corresponding control signal is not limited to 2 bits, and may be any multiple bits.

The embodiment of the application has the following beneficial effects:

(1) During the power-on period of the LDO circuit, a plurality of power supply branches can be controlled to be sequentially conducted, the overshoot amplitude of the output voltage is greatly reduced, the phenomenon that the power supply voltage of the system is pulled down due to the fact that the overshoot amplitude of the output voltage of the LDO circuit is too large can be avoided, and the stability of the system is improved.

(2) The LDO circuit may include a supply branch for responding to an undershoot and/or a discharge branch for responding to an overshoot, and may be configured to provide a fast response to the undershoot by turning on the supply branch when the undershoot is generated by the output voltage, and to provide a fast response to the overshoot by turning on the discharge branch when the overshoot is generated by the output voltage.

(3) And when the undershoot is responded, the plurality of power supply branches are controlled to be sequentially conducted, and/or when the undershoot is responded, the plurality of discharge branches are controlled to be sequentially conducted, so that the transient power consumption of the LDO circuit can be reduced.

The embodiment of the application also provides a control method of the LDO circuit, which can be used for controlling the LDO circuit. Referring to the control method flowchart of the LDO circuit shown in fig. 14, the method may be as follows:

Step 1401, during power-up of the LDO circuit, controlling at least two of the plurality of power supply branches to be turned on sequentially;

step 1402, based on the output circuit, outputs an output voltage of the LDO circuit.

Optionally, the method further comprises:

Optionally, when the output voltage of the LDO circuit undershoots, at least one of the turned-off power supply branches is turned on, including: when the output voltage of the LDO circuit undershoots, a plurality of turned-off power supply branches are sequentially turned on;

When the output voltage of the LDO circuit overshoots, at least one conducting power supply branch is turned off, and the method comprises the following steps: when the output voltage of the LDO circuit overshoots, the plurality of conducted power supply branches are turned off in sequence.

the method further comprises the steps of:

Optionally, when the output voltage of the LDO circuit undershoots, the adjusting the second control signal of the at least one power supply branch from the first off level to the first on level includes: when the output voltage of the LDO circuit undershoots, the second control signals of the power supply branches are sequentially adjusted from a first turn-off level to a first turn-on level;

When the output voltage of the LDO circuit overshoots, the adjusting the second control signal of at least one power supply branch from the first on level to the first off level includes: when the output voltage of the LDO circuit overshoots, the second control signals of the power supply branches are sequentially adjusted from the first on level to the first off level.

Optionally, the output circuit further comprises at least one discharge branch;

the method further comprises the steps of:

Optionally, the switching on at least one off discharge branch when the output voltage of the LDO circuit overshoots includes:

the method further comprises the steps of:

when the output voltage of the LDO circuit overshoots, the third control signal of at least one discharging branch is adjusted from a second off level to a second on level.

Optionally, when the output voltage of the LDO circuit overshoots, the adjusting the third control signal of the at least one discharge branch from the second off level to the second on level includes:

the method further comprises the steps of:

when the output voltage overshoots, controlling the output voltage detection module to output an overshoot signal, wherein the overshoot signal is used for indicating that the output voltage is in an overshoot state;

when the output voltage generates undershoot, the output voltage detection module is controlled to output an undershoot signal, and the undershoot signal is used for indicating that the output voltage is in an undershoot state.

the method further comprises the steps of:

When the power supply branch matched with the first switch module is conducted, the first switch module is controlled to be in a conducting state;

when the power supply branch matched with the first switch module is turned off, controlling the first switch module to be in an off state;

when the power supply branch adapted by the second switch module is conducted, the second switch module is controlled to be in an off state,

and when the power supply branch matched with the second switch module is turned off, controlling the second switch module to be in a conducting state.

The second end of the second feedback resistor unit is used for grounding.

In the embodiment of the application, at least two of the power supply branches can be controlled to be sequentially conducted during the power-on period of the LDO circuit, so that the overshoot amplitude of the output voltage is greatly reduced, the power supply voltage of the system can be prevented from being pulled down due to the too large overshoot amplitude of the output voltage of the LDO circuit, and the stability of the system is improved.

The exemplary embodiment of the application also provides a chip, which comprises the LDO circuit provided by the embodiment of the application. In the embodiment of the application, at least two of the power supply branches can be controlled to be sequentially conducted during the power-on period of the LDO circuit, so that the overshoot amplitude of the output voltage is greatly reduced, the power supply voltage of the chip system can be prevented from being pulled down due to the too large overshoot amplitude of the output voltage of the LDO circuit, and the stability of the chip system is improved.

The embodiment of the application also provides electronic equipment, which comprises the LDO circuit provided by the embodiment of the application. In the embodiment of the application, at least two of the power supply branches can be controlled to be sequentially conducted during the power-on period of the LDO circuit, so that the overshoot amplitude of the output voltage is greatly reduced, the power supply voltage of the electronic equipment system can be prevented from being pulled down due to the too large overshoot amplitude of the output voltage of the LDO circuit, and the stability of the electronic equipment system is improved.

The LDO circuit, the control method, the chip and the electronic device provided by the application are described in detail, and specific examples are applied to illustrate the principle and the implementation of the application, and the description of the above examples is only used for helping to understand the method and the core idea of the application; meanwhile, as those skilled in the art will have variations in the specific embodiments and application scope in accordance with the ideas of the present application, the present description should not be construed as limiting the present application in view of the above.

Claims

1. The LDO circuit is characterized by comprising an output circuit, wherein the output circuit comprises a plurality of power supply branches;

the output circuit is configured to sequentially conduct at least two of the plurality of power supply branches during power-up of the LDO circuit to reduce an overshoot amplitude of an LDO output voltage during power-up;

the LDO circuit further comprises an amplifying circuit, a first feedback resistance unit and a second feedback resistance unit, wherein,

the second end of the second feedback resistor unit is used for being grounded;

the output circuit further comprises at least one discharge branch;

the output circuit is further configured to sequentially turn on the plurality of turned-off discharge branches when an overshoot occurs in the output voltage of the LDO circuit;

the output circuit further comprises a switch module group which is respectively matched with the power supply branches, the switch module group comprises a first switch module and a second switch module, the first switch module is connected in series with the matched power supply branches, and the second switch module is connected in parallel with the matched power supply branches;

2. The LDO circuit of claim 1, further comprising a first control module for generating a first control signal for a power supply branch during power up of the LDO circuit, the first control signal comprising a first off level for turning off the power supply branch and a first on level for turning on the power supply branch.

3. The LDO circuit of claim 2, wherein the first control module is configured to sequentially adjust the first control signals of at least two power supply branches from a first off level to a first on level during power up of the LDO circuit.

4. The LDO circuit of claim 1, wherein the output circuit is further configured to:

5. The LDO circuit of claim 4, wherein the output circuit is further configured to:

6. The LDO circuit of claim 4, further comprising a second control module for generating a second control signal for the power supply branch, the second control signal comprising a first off level for turning off the power supply branch and a first on level for turning on the power supply branch;

the second control module is configured to:

7. The LDO circuit of claim 6, wherein the second control module is further configured to:

8. The LDO circuit of claim 1, further comprising a third control module for generating a third control signal for the discharge leg, the third control signal comprising a second off level for turning off the discharge leg and a second on level for turning on the discharge leg;

9. The LDO circuit of claim 8, wherein the third control module is configured to sequentially adjust third control signals of a plurality of discharge legs from a second off level to a second on level when an overshoot occurs in an output voltage of the LDO circuit.

10. The LDO circuit of claim 1, further comprising an output voltage detection module;

11. A control method of an LDO circuit, wherein the LDO circuit comprises an output circuit comprising a plurality of power supply branches;

the second end of the second feedback resistor unit is used for being grounded;

the output circuit further comprises at least one discharge branch;

The method comprises the following steps:

during the power-on period of the LDO circuit, at least two of the power supply branches are controlled to be sequentially conducted, so that the overshoot amplitude of the LDO output voltage during power-on is reduced;

outputting an output voltage of the LDO circuit based on the output circuit;

the method further comprises the steps of:

when the output voltage of the LDO circuit overshoots, a plurality of turned-off discharging branches are sequentially turned on;

12. A chip comprising the LDO circuit of any of claims 1-10.

13. An electronic device comprising the LDO circuit of any of claims 1-10.