CN114860017A

CN114860017A - LDO circuit, control method, chip and electronic equipment

Info

Publication number: CN114860017A
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: 2022-08-05
Anticipated expiration: 2042-04-15
Also published as: CN114860017B

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 comprising a plurality of power supply branches; the output circuit is configured to sequentially turn on at least two of a plurality of power supply branches during power-up of the LDO circuit. By the adoption of the method and the device, 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 application relates to the technical field of electronics, in particular to an LDO circuit, a control method, a chip and electronic equipment.

Background

A Low-Dropout Regulator (LDO) circuit is widely applied to different electronic devices by virtue of its simple circuit, small size, Low power consumption and Low cost, and provides power for each module therein.

With the smaller and smaller chip size and the lower and lower power consumption, the performance requirement of the LDO is higher and higher. Especially in wearable devices, the stability of the output voltage and the response speed of the LDO to load transient changes during power-on directly determine the performance of the whole chip.

During the power-on process of the LDO circuit, the output voltage suddenly increases to generate overshoot, and the risk that the power supply voltage is pulled down is increased. Therefore, it is desirable 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, embodiments of the present application provide an LDO circuit, a control method, a chip, and an electronic device, which can reduce an overshoot amplitude of an output voltage in a power-on process of an LDO. The technical scheme is as follows:

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

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

Optionally, the LDO circuit further includes a first control module, the first control module is configured to generate a first control signal of the power supply branch during power-up of the LDO circuit, and the first control signal includes a first turn-off level for turning off the power supply branch and a first turn-on level for turning on the power supply branch.

Optionally, the first control module is configured to adjust the first control signals of the at least two power supply branches from the first off level to the first on level in sequence 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 power supply branch which is turned off is turned on; and/or

And when the output voltage of the LDO circuit is overshot, at least one conducting power supply branch is switched off.

Optionally, the output circuit is further configured to:

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

And when the output voltage of the LDO circuit is overshot, the plurality of conducted power supply branches are sequentially turned off.

Optionally, the LDO circuit further includes a second control module, where the second control module is configured to generate a second control signal for the power supply branch, and the second control signal includes a first turn-off level for turning off the power supply branch and a first turn-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, adjusting a second control signal of at least one power supply branch circuit from a first turn-off level to a first turn-on level; and/or

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

Optionally, the second control module is configured to:

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

And when the output voltage of the LDO circuit is overshot, the second control signals of the plurality of power supply branches are sequentially adjusted from the first on level to the first off level.

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

the output circuit is further configured to turn on at least one of the turned-off discharge branches when an output voltage of the LDO circuit overshoots.

Optionally, the output circuit is further configured to turn on the plurality of turned-off discharging branches in sequence when the 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 for the discharging branch, and the third control signal includes a second turn-off level for turning off the discharging branch and a second turn-on level for turning on the discharging branch;

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

Optionally, the third control module is configured to adjust the third control signals of the plurality of discharging branches from the second off level to the second on level in sequence when the 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, and the overshoot signal is used for indicating that the output voltage is in an overshoot state; when the output voltage undershoots, an undershoot signal is output, and 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, 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 switch module is configured to be in an on state when the adapted power supply branch is on and in an off state when the adapted power supply branch is 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 includes 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 a reference voltage, the second input end of the amplifying circuit is used for receiving a 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 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 resistance unit is connected with the output end of the LDO circuit, and the second end of the first feedback resistance unit is connected with the first end of the second feedback resistance unit;

and the second end of the second feedback resistance unit is used for grounding.

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

controlling at least two of a plurality of power supply branches to be sequentially conducted during power-up of the LDO circuit;

based on the output circuit, output the output voltage of the LDO circuit.

According to another aspect of the present application, a chip is provided, which includes the LDO circuit.

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

In this application, during the power-on of LDO circuit, can control two at least in a plurality of power supply branch roads and switch on in proper order, the overshoot amplitude of significantly reducing output voltage, and then can avoid the mains voltage of system to be drawn down because of the too big overshoot amplitude of the output voltage of LDO circuit, improved the stability of system.

Drawings

Further details, features and advantages of the present application are disclosed in the following description of exemplary embodiments, which description should be taken in conjunction with the accompanying 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 illustrates a power branch schematic provided in accordance with an exemplary embodiment of the present application;

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

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

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

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

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

Detailed Description

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

The term "include" and variations thereof as used herein are 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". Relevant definitions for other terms will be given in the following description. It should be noted that the terms "first", "second", and the like in the present application are only used for distinguishing different devices, modules or units, and are not used for limiting the order or interdependence relationship of the functions performed by the devices, modules or units.

It is noted that references to "a", "an", and "the" modifications in this application are intended to be illustrative rather than limiting, and that those skilled in the art will recognize that reference to "one or more" unless the context clearly dictates otherwise.

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

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

Referring to the schematic diagram 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 regulator 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 include the output circuit, the amplifying circuit, the first feedback resistance unit, and the second feedback resistance unit, wherein: the first input end of the amplifying circuit is used for receiving a reference voltage, the second input end of the amplifying circuit is used for receiving a 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 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 resistance unit is connected with the output end of the LDO circuit, and the second end of the first feedback resistance unit is connected with the first end of the second feedback resistance unit; the second end of the second feedback resistance unit is connected with the ground.

The configuration of the output circuit will be described below, and the rest of the circuits can be implemented by using the existing principle, and the implementation principle of the rest of the circuits is not described in this embodiment. The output circuit may be configured to:

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

In one possible implementation, during power-up of the LDO circuit, any of the plurality of power supply branches may be controlled to be turned on in sequence to reduce an overshoot magnitude 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 circuits are sequentially conducted, the instantaneous power conducted each time is smaller, and the overshoot amplitude of the output voltage is also smaller.

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

The first control module may be configured to:

during the power-up period of the LDO circuit, the 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 turn-off level and the first turn-on level are opposite. 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 a high level, and the first turn-off level may be a low level; when the power supply branch is enabled at a low level, the first turn-on level may be a low level, and the first turn-off level may be a high level. The present embodiment does not limit the specific power supply branch and the enable signal thereof.

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

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

Wherein, the time when each first control signal jumps from the first off level to the first on level is different.

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

Optionally, for each time instant when the first control signal transitions from the first off level to the first on level, the time interval between every two adjacent time instants 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 adjusted, 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 supply branch is on and in an off-state when the adapted supply branch is off;

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

Alternatively, when the first switch module is controlled based on the first control signal of the adapted power supply branch, the second switch 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 at a first on level and to be turned off when the first control signal of the adapted power supply branch is at 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 at a first on level and to be turned off when the signal opposite to the first control signal of the adapted power supply branch is at a first off level.

On this basis, when the power supply branch road turn-offs, can with the first switch module parallel access's that turns off the output of LDO circuit, be equivalent to at the output parallel access of LDO circuit electric capacity, can play the effect of stable output voltage, further improve LDO circuit output voltage's stability.

After the output voltage is stabilized, the output voltage of the LDO changes abruptly with the change of the load current, and an overshoot or an undershoot is generated. Therefore, the application also provides the LDO circuit which can realize quick response to overshoot or undershoot.

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

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

And when the output voltage of the LDO circuit overshoots, at least one conducting power supply branch is switched off.

In one possible embodiment, during power-up of the LDO circuit, part of the power supply branches may be turned on, and the remaining power supply branches remain turned off, and a fast response to an undershoot is achieved by the turned-off power supply branches. When the load current of the LDO circuit is suddenly changed from light load to heavy load, the output voltage of the LDO circuit is suddenly changed along with the sudden change, and undershoot is generated. At this time, the power supply branch in the off state may be turned on, so as to increase the voltage provided to the output voltage, and facilitate the output voltage of the LDO circuit to recover to a stable value. It should be noted that the switched-on power supply branch may not be switched off in a steady state. For example, in response to the first undershoot, power supply branch a is turned on, power supply branch B remains off, power supply branch a is not turned off after stabilization, and power supply branch B is turned on in response to the second undershoot.

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

Of course, the output circuit may be further configured to turn on at least one of the turned-off power supply branches when the output voltage of the LDO circuit undershoots, and to turn off at least one of the turned-on power supply branches when the output voltage of the LDO circuit overshoots. That is, the fast response to undershoot or overshoot can be realized by controlling the power supply branches.

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

And when the output voltage of the LDO circuit overshoots, the plurality of conducted power supply branches are sequentially turned off.

In a possible implementation manner, when the output voltage generates an undershoot, any plurality of power supply branches can be controlled to be sequentially switched on under the condition that a plurality of power supply branches are switched off, so that quick response to the undershoot is realized. The plurality of power supply branches that are turned on may be the same as or any number of power supply branches that are turned off before the power supply branches are turned on. Because switch on a plurality of power supply branch roads simultaneously, be equivalent to once switch on the switch tube that the size is several times, required time is long, the consumption is big, consequently compares in the technical scheme who switches on a plurality of power supply branch roads simultaneously, switches on the consuming time reduction of power supply branch road in proper order, can reduce transient state consumption.

Under the condition that a plurality of conducted power supply branches exist, when the output voltage generates overshoot, any plurality of conducted power supply branches can be controlled to be sequentially turned off, and quick response to the overshoot is achieved. Because turn off a plurality of power supply branch roads simultaneously, turn off the switch tube that the size is several times in a similar to once, required time is long, the consumption is big, consequently compares in the technical scheme who turns off a plurality of power supply branch roads simultaneously, and the consuming time of turning off the power supply branch road in proper order reduces, can reduce transient state consumption.

It should be noted that, by increasing or decreasing the conducting number of the power supply branches, the overshoot voltage of the LDO can be pulled down at the instant of turning off the power supply branches, or the undershoot voltage of the LDO can be pulled up at the instant of turning on the power supply branches, so as to alleviate the overshoot or undershoot of the instantaneous voltage caused by the load change. After one or more power supply branches are turned off/on, the output voltage of the LDO circuit is stabilized to the preset reference voltage value again under the action of an operational amplifier feedback loop in the LDO circuit, and the influence of the conducting number of the power supply branches is avoided.

In one possible embodiment, the plurality of supply branches in the output circuit includes at least one supply branch operable to respond to the overshoot and at least one normally-on supply branch. The plurality of power supply branches available for responding to the overshoot means that a basic function of the LDO circuit to output the regulated voltage is not affected when the at least one power supply branch available for responding to the overshoot is all turned off. For example, during operation of the LDO circuit, after one or more power supply branches available for responding to the overshoot are all turned off, the LDO circuit may still maintain the voltage output through the at least one normally-on power supply branch, which may not result in the LDO output voltage being 0. In this example, the number of normally-on supply branches may be set according to the required LDO minimum load capacity, such that the at least one normally-on supply branch can meet the minimum load requirement when all supply branches available to respond to the overshoot are turned 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 the power supply branches that are turned on in the output circuit may be greater than or equal to the set number.

Further alternatively, the first number of supply branches switched on in response to undershoot may be determined in dependence on a magnitude of the undershoot voltage, and/or the second number of supply branches switched off in response to overshoot may be determined in dependence 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 the power supply branches which are turned off are turned on; and/or, when the output voltage of the LDO circuit overshoots, the second number of the conducting power supply branches are turned off. On the basis, the adaptability of the number of the power supply branches for quick response to the overshoot amplitude or the 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, and the second control module may be configured to generate a second control signal for the power supply branches, where the second control signal includes a first turn-off level for turning off the power supply branches and a first turn-on level for turning on the power supply branches, and each power supply branch has 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 the 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 may be switched into the power supply branch for fast response.

Before responding to the undershoot, the second control signal for the power supply branch responding to the undershoot may be the first turn-off level, and the corresponding power supply branch is controlled to be in the turn-off state. When the output voltage generates an undershoot, the second control module may determine 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. And the power supply branch is switched on when the second control signal jumps from the first off level to the first on level, so that the fast response to the undershoot is realized.

Before the overshoot is responded, the second control signal of the power supply branch responding to the overshoot can be the first conducting level, and the corresponding power supply branch is controlled to be in a conducting state. When the output voltage generates overshoot, the second control module can determine specific control over 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 the first on level to the first off level. And the power supply branch is switched off when the second control signal jumps from the on level to the off level, so that the fast response to the overshoot is realized. Optionally, corresponding to a case where the plurality of power supply branches are controlled to achieve a fast response, the second control module may be further configured to:

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

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 switched-off power supply branches can be controlled to be switched on at different moments, namely, sequentially switched on.

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 sequentially turned on. Optionally, in the process of one response, for the time when each second control signal jumps from the on level to the off level, the time intervals of every two adjacent times are the same, or for the time when each second control signal jumps from the off level to the on level, the time intervals of every two adjacent times are the same. On the 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, the first control signal output by the first control module can be selected to control each power supply branch circuit during the power-on period of the LDO circuit; after that, the second control signal output by the second control module can be selected to control each power supply branch.

Optionally, the power supply branch for fast response may also have the above switch module group adapted to the power supply branch shown in fig. 4, which is not described herein again.

Optionally, referring to the LDO circuit schematic shown in fig. 7, the output circuit may further include at least one discharging branch. The current direction of the discharging branch circuit is different from that 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:

and when the output voltage of the LDO circuit is overshot, at least one of the discharge branches which is switched off is switched on.

In a possible implementation manner, after the LDO circuit is powered on, the initial state of the discharge branch may be an off state, and a fast response to the overshoot is achieved through the off discharge branch. When the load current of the LDO circuit is suddenly changed and the load is switched from heavy load to light load, the output voltage of the LDO circuit is suddenly changed, and overshoot is generated. At this time, the discharging branch in the off state can be turned on, so that discharging is accelerated, and the output voltage of the LDO circuit is promoted to be restored to a stable value. It should be noted that the turned-on discharge branch may not be turned off in a steady state. For example, discharge branch a is turned on in response to the first overshoot, discharge branch B remains off, discharge branch a is not turned off after stabilization, and discharge branch B is turned on in response to the second overshoot.

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

Optionally, when the output circuit comprises 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 is overshot, the plurality of discharge branches which are turned off are sequentially turned on.

In a possible implementation manner, when the output voltage generates overshoot, when a plurality of discharging branches exist, any plurality of discharging branches can be controlled to be sequentially conducted, and quick response to the overshoot is achieved. The plurality of discharge branches that are turned on and the plurality of discharge branches that are turned off before turning on may be the same, or may be any plurality of discharge branches that are turned off. Because switch on a plurality of branch circuits that discharge simultaneously, be equivalent to once switch on the switch tube that the size is several times, required time is long, the consumption is big, consequently compares in the technical scheme who switches on a plurality of branch circuits that discharge simultaneously, and the consuming time that switches on the branch circuit that discharges in proper order reduces, can reduce transient state consumption.

It should be noted that, in the present application, by increasing the conducting number of the discharging branch, the overshoot voltage of the LDO can be pulled down at the instant of conducting the discharging branch. After one or more discharging branches are conducted, the output voltage of the LDO circuit is stabilized to the preset reference voltage value again under the action of an operational amplifier feedback loop in the LDO circuit, and the influence of the conducting number of the discharging branches is avoided.

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

Optionally, referring to the LDO circuit schematic shown in fig. 8, the LDO circuit may further include a third control module, and the third control module may be configured to generate a third control signal for the discharging branches, where the third control signal includes a second turn-off level for turning off the discharging branches and a second turn-on level for turning on the discharging branches, and each discharging branch has 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 both the first control module and the second control module.

The third control module may be configured to:

and when the output voltage of the LDO circuit is overshot, adjusting the third control signal of at least one discharging branch circuit from the second turn-off level to the second turn-on level.

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

In one possible embodiment, the third control signal output by the third control module may be connected to the corresponding discharge branch. Before responding to the overshoot, the third control signal for the discharging branch responding to the overshoot may be the second turn-off level, controlling the corresponding discharging branch to be in the turn-off state.

When the output voltage generates overshoot, the third control module may determine specific control of the discharging branch through a third preset logic, and adjust a third control signal for the discharging branch in response to the overshoot from the second turn-off level to the second turn-on level. And the discharging branch is switched off when the third control signal jumps from the second turn-off level to the second turn-on level, so that the quick response to the overshoot is realized.

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

and when the output voltage of the LDO circuit overshoots, the third control signals of the plurality of discharging 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, the plurality of discharge branches which are turned off can be controlled to be turned on at different moments, namely, to be turned on in sequence.

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

Optionally, referring to the schematic diagram of the LDO circuit shown in fig. 9, the LDO circuit may further include an output voltage detection module, and the output voltage detection module may detect that the output voltage of the LDO circuit overshoots or undershoots.

The output voltage detection module can be configured to output an overshoot signal when the output voltage overshoots; and when the output voltage generates undershoot, outputting an undershoot signal.

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

In a possible embodiment, an input terminal of the output voltage detection module may be connected to an output terminal of the LDO circuit, and configured to detect whether an output voltage of the LDO circuit is smaller than a first threshold or larger than a second threshold. When the output voltage is less than the first threshold, it indicates that the output voltage generates an undershoot, at which time, 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, 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. Furthermore, when receiving the undershoot signal, the control module may determine 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 over 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 discharging branch through the third preset logic, and adjusting a third control signal of the discharging branch for responding to the overshoot from a second turn-off level to a second turn-on level.

For the conditions belonging to different control modules, when the power supply branch circuit is adopted to realize the quick response to the undershoot, the undershoot signal output by the output voltage detection module can be connected to the second control module; when the power supply branch circuit is adopted to rapidly respond to the overshoot, the overshoot signal can be accessed to the second control module; when the discharge branch circuit is adopted to realize quick response to the overshoot, the overshoot signal can be connected to the third control module. The processing of the second control module and the third control module is the same as the above, and is not described again.

Further optionally, corresponding to the above case where the number of branches is determined 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 information of the first number to a second control module;

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

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

In a possible embodiment, a corresponding relationship between the magnitude of the undershoot voltage and the number of conducting power supply branches may be preset, and further, when the output voltage is smaller than the first threshold, the first number of power supply branches required to be conducted by the current undershoot voltage may be determined according to the corresponding relationship.

In another possible implementation manner, the number of the power supply branches that are determined to be turned on in response to the undershoot according to the magnitude of the current output voltage may specifically be: determining the size of a difference value between the current output voltage and a preset reference voltage according to the size of the current output voltage; based on the magnitude of the difference, a first number of supply branches to conduct in response to the undershoot is determined. Similarly, a corresponding relationship between the magnitude of the difference and the number of branches to be responded (which may be referred to as a first number) may be preset, and further, when the output voltage is smaller than the first threshold, the first number of power supply branches required to be turned on by the current undershoot voltage may be determined according to the corresponding relationship.

The embodiment of determining the second number or the third number is the same as the above when the power supply branch or the discharge branch is adopted to realize the fast response to the overshoot, and the details are not repeated here.

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

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 corresponding relationship between the magnitude of the difference and the number of branches to be responded (in this case, the sum of the second number and the third number may be referred to) may be preset, and further, when the output voltage is greater than the second threshold, the number of branches required to be responded by the current overshoot voltage may be determined according to the corresponding relationship. Furthermore, the second number of the power supply branches to be turned off and the third number of the discharge branches to be turned on may be respectively determined according to the number of the branches.

Optionally, the correspondence between the size of the difference and the number of branches to be responded in the foregoing embodiment 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 responding to an undershoot with the supply branch, the second control module may be configured to: when the undershoot signals and the information of the first number are received, the power supply branch to be conducted is determined according to the second number and the current power supply branch to be turned off, and the second control signal of the power supply branch to be conducted is adjusted to the first conducting level from the first turning-off level.

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

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

When the discharge branch is employed to respond to the overshoot, the third control module may be configured to: when the information of the overshoot signal and the third number is received, the discharging branch to be conducted is determined according to the third number and the currently-turned-off discharging branch, and the third control signal of the discharging branch to be conducted is adjusted from the second turn-off level to the second turn-on level.

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

The present embodiment does not limit the strategy adopted for determining 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.

Described above are embodiments in which the LDO circuit achieves a fast response to undershoot or overshoot after one power-up. When the LDO circuit is powered on every 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 reset, so that quick response is realized through the embodiment after the LDO circuit is powered on this time. The initial state of each branch may be preset, and each time the power supply circuit is powered on, the initial state of each branch in the output circuit may be generally the on state of at least two power supply branches and the off state of all discharging branches.

The embodiment of the application can obtain 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 problem that the power 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 can 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 switched on to realize quick response to the undershoot, and when the output voltage generates overshoot, the power supply branch circuit is switched off and/or the discharge branch circuit is switched on to realize quick response to the overshoot.

(3) When the fast response to the undershoot or the overshoot is realized, the plurality of branches are controlled to be sequentially switched on or switched off, and the transient power consumption of the LDO circuit can be reduced.

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

Referring to the schematic diagram of the LDO circuit 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, the plurality of power supply branches may be divided into a power-on start branch group and an undershoot regulation branch group, and the plurality of discharge branches may be referred to as an overshoot regulation branch group.

The power-on starting branch group corresponds to the power supply branch which is conducted during the power-on period and comprises 3 MOS (field effect transistors) MP1, MP2 and MP3 which are connected in parallel, each MOS is matched with two switches, one switch is connected with the MOS in series, the other switch is connected with the MOS in parallel to form 3 power supply branches, the series-connected switches (corresponding to the first switch module) are controlled based on S1P, S2P and S3P signals (corresponding to the first control signal), and the parallel-connected switches (corresponding to the second switch module) are controlled based on S1N, S2N and S3N signals (corresponding to the signals opposite to the first control signal).

The lower-impact regulating branch group corresponds to the power supply branch for responding to the lower impact and comprises 2 MOS tubes MP4 and MP5 which are connected in parallel, 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 module) which are connected in series are controlled based on S4P and S5P signals (corresponding to the second control signal), and the switches (corresponding to the second switch module) which are connected in parallel are controlled based on S4N and S5N signals (corresponding to the signal opposite to the second control signal).

The overshoot regulation branch group corresponds to the discharge branch for responding to the overshoot, and comprises 2 MOS transistors MN6 and MN7 connected in parallel, so as to form 2 discharge branches, and control is performed based on the S6P signal and the S7P signal (corresponding to the third control signal).

The first ends of the MOS tubes MP1, MP2, MP3, MP4 and MP5 are all used for being connected with a power supply voltage VDD, the second ends of the MOS tubes are all connected with the output end of the LDO circuit, and the third ends (namely control ends) of the MOS tubes are all connected with the output end of the error amplifier AMP. First ends of the MOS tubes MN6 and MN7 are both connected with an output end of the LDO circuit, second ends of the MOS tubes are both grounded, and third ends (namely control ends) of the MOS tubes are respectively connected with S6P and S7P signals.

The load resistor capacitor includes a load resistor ESR and a load capacitor 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 to 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 is connected with the resistor R2. One end of the resistor R2 is connected to the resistor R1, and the other end is grounded.

The error amplifier AMP corresponds to the amplifying circuit, and has an inverting input terminal for receiving the reference voltage VREF, a non-inverting input terminal for receiving the feedback voltage VFB, and output terminals connected to control terminals of the MOS transistors MP1, MP2, MP3, MP4, MP5, MP6, and MP7, respectively. 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 starting control circuit corresponds to the first control module and is used for receiving the enable signal ENN and the band gap reference circuit signal BGR _ OK and outputting signals S1P, S2P, S3P, S1N, S2N and S3N. 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 signals S1P, S2P and S3P, 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 and control circuit.

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

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

When the enable signal ENN jumps from a high level to a low level, the enable signal ENN is enabled, and the LDO circuit starts to be powered on. At this time, the BGR _ OK signal may correspondingly transition from a low level to a high level. The power-on stage starting control circuit delays the BGR _ OK signal (a transition signal from low to high) by t1 in sequence under the control of an enable signal ENN to obtain signals S1P, S2P and S3P: the timing at which the S1P signal jumps from low to high is the same as the BGR _ OK signal (there may be a certain time interval), and the timing at which the S2P signal jumps from low to high is delayed by the S1P signal delay time t1, and the timing at which the S3P signal jumps from low to high is delayed by the S2P signal delay time t 1.

In fig. 11, a solid line in the schematic diagram of the output voltage LDO _ VOUT indicates a voltage change of the output voltage LDO _ VOUT when MP1, MP2, and MP3 are sequentially turned on, and a dotted line indicates a voltage change of the output voltage LDO _ VOUT when MP1, MP2, and MP3 are simultaneously turned on. It can be seen that under the control of the signals S1P, S2P, S3P, S1N, S2N, and S3N, the 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 during power-on is greatly reduced compared with the overshoot amplitude of the output voltage LDO _ VOUT of the LDO circuit when the LDO circuit is simultaneously turned on MP1, MP2, and MP3, and therefore the power voltage can be prevented from being pulled down due to too large overshoot of the output voltage LDO _ VOUT of the LDO circuit, and the stability of the system is improved.

The operation principle of the LDO circuit for achieving 1-bit transient response regulation will be described with reference to the timing diagram shown in fig. 12.

After the output voltage LDO _ VOUT is stabilized, when the load current I _ load suddenly changes, the light load Imin is switched to the heavy load Imax, and the output voltage of the LDO suddenly changes along with the light load Imin, so that an undershoot is generated. At this time, the output voltage detection circuit outputs one positive pulse signal (corresponding to the undershoot signal described above) under the control of the S1P, S2P, 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 a positive pulse signal S5P and a negative pulse signal S5N, and controls the conduction of a MOS (metal oxide semiconductor) tube MP4 or MP5 in the down-pulse regulating branch group (namely, a 1-bit control signal controls 1 power supply branch), thereby increasing the power supply branches, and further quickly recovering the output voltage of the LDO to a stable value.

When the load current I _ load suddenly changes, the heavy load Imax is switched to the light load Imin, and the output voltage of the LDO suddenly changes along with the change, so that overshoot is generated. At this time, the output voltage detection circuit outputs an undershoot signal (corresponding to the overshoot signal described above) under the control of the S1P, S2P, 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 1-bit control signal) to control the conduction of the MOS transistor MP6 or MP7 in the overshoot regulation branch group, thereby increasing a discharge branch and further quickly restoring the output voltage of the LDO to a stable value.

In fig. 12, a solid line in the schematic diagram of the output voltage LDO _ VOUT indicates a voltage change of the output voltage LDO _ VOUT when transient response regulation is performed according to the present application, and a dotted line indicates a voltage change of the output voltage LDO _ VOUT when transient response regulation is not performed. It can be seen that, when the method is adopted, the time for the output voltage LDO _ VOUT to recover to the stable value is shortened, and the transient response performance of the LDO circuit is improved.

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

After the output voltage LDO _ VOUT is stabilized, when the load current I _ load suddenly changes, the light load Imin is switched to the heavy load Imax, and the output voltage of the LDO suddenly changes along with the light load Imin, so that an undershoot is generated. At this time, the output voltage detection circuit follows a positive pulse signal (corresponding to the undershoot signal described above) under the control of the S1P, S2P, 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, and the MOS tubes MP4 and MP5 in the down-stroke regulating branch group are controlled to be conducted step by step, so that power supply branches are added, and the output voltage of the LDO is quickly recovered to a stable value.

When the load current I _ load suddenly changes, the heavy load Imax is switched to the light load Imin, and the output voltage of the LDO suddenly changes along with the change, so that overshoot is generated. At this time, the output voltage detection circuit outputs an undershoot signal (corresponding to the overshoot signal described above) under the control of the S1P, S2P, and S3P signals. The negative pulse signal acts on the transient response switch regulating circuit, so that the transient response switch regulating circuit generates two negative pulse signals S6P and S7P (namely 2-bit control signals) according to different threshold voltages, and the MOS transistors MP6 and MP7 in the overshoot regulating branch set are controlled to be conducted step by step, so that a discharge branch is added, and the output voltage of the LDO is quickly recovered to a stable value.

In fig. 13, a solid line in the schematic diagram of the output voltage LDO _ VOUT indicates a voltage change of the output voltage LDO _ VOUT when transient response regulation is performed with the stepwise conduction, and a dotted line indicates a voltage change of the output voltage LDO _ VOUT when transient response regulation is not performed with the stepwise conduction. It can be seen that when the step-by-step conduction is adopted, the multi-bit fine regulation can be carried out on the overshoot or undershoot amplitude of the output voltage LDO _ VOUT, so that the LDO has the effect of fast response to the output voltage of the LDO, and the transient power consumption can be reduced.

In this embodiment, for example, a group of 2 MOS transistors is included, 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 multi-bit.

The embodiment of the application can obtain the following beneficial effects:

(1) during the power-on period of the LDO circuit, the plurality of power supply branches can be controlled to be sequentially conducted, the overshoot amplitude of the output voltage is greatly reduced, the problem that the system power supply voltage 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 can comprise a power supply branch circuit for responding to undershoot and/or a discharge branch circuit for responding to overshoot, and when the output voltage generates undershoot, the fast response to the undershoot is realized by conducting the power supply branch circuit, and when the output voltage generates overshoot, the fast response to the overshoot is realized by conducting the discharge branch circuit.

(3) When the undershoot is responded, the plurality of power supply branches are controlled to be sequentially conducted, and/or when the overshoot is responded, the plurality of discharging 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 flowchart of the control method of the LDO circuit shown in fig. 14, the method may be as follows:

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

in step 1402, the output voltage of the LDO circuit is output based on the output circuit.

Optionally, the method further includes:

during the power-on period of the LDO circuit, the 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.

Optionally, the method further includes:

Optionally, when the output voltage of the LDO circuit undershoots, the switching on at least one power supply branch that is turned off includes: when the output voltage of the LDO circuit undershoots, the plurality of power supply branches which are turned off 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: and when the output voltage of the LDO circuit is overshot, the plurality of conducted power supply branches are sequentially turned off.

the method further comprises the following steps:

Optionally, when the output voltage of the LDO circuit undershoots, 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, second control signals of a plurality of 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 second control signal of at least one power supply branch is adjusted from the first on level to the first off level, and the method comprises the following steps: and when the output voltage of the LDO circuit is overshot, the second control signals of the plurality of power supply branches are sequentially adjusted from the first on level to the first off level.

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

the method further comprises the following steps:

and when the output voltage of the LDO circuit is overshot, at least one of the discharge branches which is turned off is turned on.

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

and when the output voltage of the LDO circuit is overshot, the plurality of discharge branches which are turned off are sequentially turned on.

the method further comprises the following steps:

and when the output voltage of the LDO circuit is in overshoot, adjusting the third control signal of at least one discharging branch circuit from the second turn-off level to the second turn-on level.

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

and when the output voltage of the LDO circuit is overshot, the third control signals of the plurality of discharging branches are sequentially adjusted from the second turn-off level to the second turn-on level.

the method further comprises the following steps:

when the output voltage is in overshoot, 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;

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

the method further comprises the following steps:

when the power supply branch adaptive to the first switch module is conducted, controlling the first switch module to be in a conducting state;

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

when the power supply branch circuit adapted to the second switch module is conducted, the second switch module is controlled to be in a turn-off state,

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

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

The exemplary embodiment of the present application also provides a chip including the LDO circuit provided in the embodiments of the present application. In the embodiment of the application, during the power-on period of the LDO circuit, at least two of a plurality of power supply branches can be controlled to be conducted in sequence, the overshoot amplitude of the output voltage is greatly reduced, the situation that the power voltage of the chip 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 chip system is improved.

The exemplary embodiment of the present application further provides an electronic device, which includes the LDO circuit provided in the embodiment of the present application. In the embodiment of the application, during the power-on period of the LDO circuit, at least two of a plurality of power supply branches can be controlled to be conducted in sequence, the overshoot amplitude of the output voltage is greatly reduced, the situation that the power supply voltage of the electronic equipment 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 electronic equipment system is improved.

The LDO circuit, the control method, the chip, and the electronic device provided in the present application are introduced in detail, and specific examples are applied in the present application to explain the principles and embodiments of the present application, and the descriptions of the above embodiments are only used to help understand the method and the core idea of the present application; meanwhile, for a person skilled in the art, according to the idea of the present application, there may be variations in the specific embodiments and the application scope, and in summary, the content of the present specification should not be construed as a limitation to the present application.

Claims

1. A low dropout regulator (LDO) circuit, comprising an output circuit comprising a plurality of power supply branches;

2. The LDO circuit of claim 1, wherein the LDO circuit further comprises 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 turn-off level for turning off the power supply branch and a first turn-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 turn-off level for turning off the power supply branch and a first turn-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, wherein the output circuit further comprises at least one discharge branch;

9. The LDO circuit of claim 8, wherein the output circuit is further configured to turn on the plurality of turned-off discharge branches in sequence when an output voltage of the LDO circuit overshoots.

10. The LDO circuit of claim 8, wherein the LDO circuit further comprises a third control module for generating a third control signal for the discharging branch, the third control signal comprising a second turn-off level for turning off the discharging branch and a second turn-on level for turning on the discharging branch;

11. The LDO circuit of claim 10, wherein the third control module is configured to sequentially adjust the third control signals of the plurality of discharging branches from the second off level to the second on level when the output voltage of the LDO circuit overshoots.

12. The LDO circuit of claim 1, wherein the LDO circuit further comprises an output voltage detection module;

13. The LDO circuit of claim 1, wherein the output circuit further comprises a set of switch modules respectively adapted to the power supply branches, the set of switch modules comprising a first switch module and a second switch module, the first switch module being connected in series with the adapted power supply branch, the second switch module being connected in parallel with the adapted power supply branch;

the first switching module is configured to be in a conducting state when the adapted power supply branch is conducting and in an off state when the adapted power supply branch is off;

14. The LDO circuit of claim 1, further comprising an amplification circuit, a first feedback resistance unit, and a second feedback resistance unit, wherein,

15. A method of controlling an LDO circuit, the LDO circuit comprising an output circuit, the output circuit comprising a plurality of power supply branches, the method comprising:

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

based on the output circuit, output the output voltage of the LDO circuit.

16. A chip comprising an LDO circuit according to at least one of claims 1-14.

17. An electronic device comprising an LDO circuit according to at least one of claims 1-14.