CN108512282A - A kind of power supply circuit, terminal device and its method for controlling power supply - Google Patents

Abstract

A kind of power supply circuit of present invention offer, terminal device and its method for controlling power supply, power supply circuit include：Power supply, buck sub-circuit, detection control sub-circuit and N number of low pressure difference linear voltage regulator LDO；The input terminal of buck sub-circuit is connect with power supply；The input terminal of LDO is connect with the output end of buck sub-circuit, and the output end of LDO is connected with corresponding load；Detection control sub-circuit is used to detect the output parameter value of N number of LDO, and the target voltage values for meeting preset condition are worth to according to the output parameter of N number of LDO, and the output voltage values for controlling buck sub-circuit are more than or equal to target voltage values.The output voltage values of buck sub-circuit can be adjusted to suitable voltage value, promote the job stability of load by power supply circuit provided in an embodiment of the present invention according to the output parameter value of N number of LDO.

Description

A power supply circuit, terminal equipment and power supply control method thereof

technical field

Embodiments of the present invention relate to the technical field of power supply, and in particular, to a power supply circuit, a terminal device and a power supply control method thereof.

Background technique

With the development of communication technology, terminal devices such as smartphones and tablets have become indispensable tools in people's daily life. In order to meet people's requirements for multi-function and high performance of terminal equipment, more and more components are integrated in terminal equipment, and the performance of each component is also getting higher and higher, such as front and rear cameras, full screen, graphics processor And the fingerprint sensor, among other things.

In order to meet the power supply requirements of each load (the load includes at least one component) in the terminal equipment, several low dropout linear regulators (Low Dropout Regulator, LDO) are arranged in the terminal equipment, and each LDO module is connected with an external power supply And at least one load is connected, so as to provide a normal working voltage for each load by stepping down and stabilizing the output voltage of the power supply through the LDO. However, due to the large variation range of the external power supply, when the input voltage value is insufficient, the voltage conversion efficiency of the LDO decreases, and the output voltage of a single LDO decreases, resulting in the output voltage of the LDO being unable to meet the needs of the load and reducing the working stability of the load.

It can be seen that the current terminal equipment has the problem that the working stability of the load is reduced due to the low output voltage of the LDO.

Contents of the invention

Embodiments of the present invention provide a power supply circuit, a terminal device and a power supply control method thereof, so as to solve the problem of lower working stability of a load caused by a low output voltage of an LDO in a current terminal device.

In order to solve the problems of the technologies described above, the present invention is achieved in that:

In the first aspect, an embodiment of the present invention provides a power supply circuit, the power supply circuit includes a power supply, a buck-boost sub-circuit, a detection control sub-circuit, and N low-dropout linear regulators LDO, where N is a positive integer, where :

The input end of the buck-boost sub-circuit is connected to the power supply;

The input end of the LDO is connected to the output end of the buck-boost sub-circuit, and the output end of the LDO is connected to a corresponding load;

The detection and control sub-circuit is used to detect the output parameter values of the N LDOs, obtain the target voltage value satisfying the preset condition according to the output parameter values of the N LDOs, and control the output of the buck-boost sub-circuit The voltage value is greater than or equal to the target voltage value.

In the second aspect, an embodiment of the present invention also provides a terminal device, including at least one load and the power supply circuit of the terminal device described above, the power supply circuit includes a power supply, a buck-boost sub-circuit, a detection and control sub-circuit, and N low-dropout linear regulators. voltage regulator LDO, where:

The input end of the buck-boost sub-circuit is connected to the power supply;

The input terminals of the LDO are all connected to the output terminals of the buck-boost sub-circuit, and the output terminals of the LDO are connected to the corresponding load;

The detection and control sub-circuit is used to detect the output parameter values of the N LDOs, obtain the target voltage value satisfying the preset condition according to the output parameter values of the N LDOs, and control the output of the buck-boost sub-circuit The voltage value is greater than or equal to the target voltage value.

In the third aspect, the embodiment of the present invention also provides a power supply control method for a terminal device, which is applied to the above-mentioned terminal device. circuit and N low-dropout linear regulators LDO; N is a positive integer, and the terminal equipment power supply control method includes:

The detection and control subcircuit detects the output parameter values of the N LDOs;

The detection control sub-circuit obtains a target voltage value satisfying a preset condition according to output parameter values of the N LDOs;

The detection control subcircuit controls the output voltage value of the step-down subcircuit to be greater than or equal to the target voltage value.

In the embodiment of the present invention, the power supply circuit includes a power supply, a buck-boost sub-circuit, a detection control sub-circuit, and N low-dropout linear regulators LDO; the input end of the buck-boost sub-circuit is connected to the power supply; the input end of the LDO It is connected to the output terminal of the buck-boost sub-circuit, and the output terminal of the LDO is connected to the corresponding load; the detection control sub-circuit is used to detect the output parameter values of N LDOs, and the preset conditions are obtained according to the output parameter values of N LDOs The target voltage value, and control the output voltage value of the step-down sub-circuit to be greater than or equal to the target voltage value. In this way, the power supply circuit can adjust the output voltage value of the buck-boost sub-circuit, that is, the input voltage value of the N LDOs, to an appropriate voltage value according to the output parameter values of the N LDOs, thereby improving the voltage conversion efficiency of each LDO, and making the The output voltage of each LDO meets the requirements of the load connected to it, improving the working stability of the load.

Description of drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the accompanying drawings that need to be used in the description of the embodiments of the present invention. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those skilled in the art, other drawings can also be obtained based on these drawings without any creative effort.

FIG. 1 is a schematic structural diagram of a power supply circuit connected to a load provided by an embodiment of the present invention;

FIG. 2 is a schematic structural diagram of a buck-boost sub-circuit provided by an embodiment of the present invention;

Fig. 3 is a schematic flowchart of a method for controlling power supply of a terminal device provided by an embodiment of the present invention.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some of the embodiments of the present invention, but not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

The power supply circuit described in the embodiment of the present invention, the power supply circuit includes a power supply, a buck-boost sub-circuit, a detection control sub-circuit, and N low-dropout linear regulators LDO, where N is a positive integer, wherein:

The input end of the buck-boost sub-circuit is connected to the power supply;

The input end of the LDO is connected to the output end of the buck-boost sub-circuit, and the output ends of the LDO are respectively connected to corresponding loads;

The detection and control sub-circuit is used to detect the output parameter values of the N LDOs, obtain the target voltage value satisfying the preset condition according to the output parameter values of the N LDOs, and control the output of the buck-boost sub-circuit The voltage value is greater than or equal to the target voltage value.

The power supply circuit described in the embodiment of the present invention can adjust the output voltage value of the buck-boost sub-circuit, that is, the input voltage value of the N LDOs, to an appropriate voltage value according to the output parameter values of the N LDOs, thereby increasing the voltage of each LDO. The voltage conversion efficiency is high, so that the output voltage of each LDO meets the needs of the load connected to it, and the working stability of the load is improved.

Please refer to FIG. 1. FIG. 1 is a schematic structural diagram of a power supply circuit connected to a load provided by an embodiment of the present invention. As shown in FIG. , and N low dropout linear regulators LDO40, where:

The input end of the buck-boost sub-circuit 20 is connected to the power supply 10;

The input ends of the N LDO40 are connected to the output ends of the step-down sub-circuit 20, and the output ends of the LDO40 are connected to the corresponding load 200;

The detection and control sub-circuit 30 is used to detect the output parameter values of the N LDO40s, obtain the target voltage value satisfying the preset condition according to the output parameter values of the N LDO40s, and control the voltage-boosting sub-circuit 20 The output voltage value is greater than or equal to the target voltage value.

It should be noted that, the output terminals of the above-mentioned LDOs are connected to the corresponding loads 200, each LDO40 in the above-mentioned N LDO40 can be connected to a load 200, and different LDO40s are connected to different loads 200, that is, the power supply circuit 100 and N The load 200 is connected, and N LDO40 is connected to N loads 200 in one-to-one correspondence; or, each LDO40 can be connected to multiple loads 200, and each LDO40 can output a voltage that meets the working requirements of multiple loads 200 connected to it. . However, FIG. 1 only shows the one-to-one connection between N LDOs 40 and N loads 200 , which is not limited here.

In the embodiment of the present invention, when the above-mentioned power supply circuit provides the electric energy of the power supply 10 to each load 200, the detection control sub-circuit 30 can detect the output parameters of each LDO40, that is, the input parameters of each load 200, according to the output of N LDO40 The parameters determine the appropriate target voltage value, and control the output voltage of the buck-boost sub-circuit 20 to be greater than or equal to the target voltage value, so as to ensure that each LDO40 inputs an appropriate voltage value and improve the working stability of the load 200 corresponding to each LDO40.

Wherein, the above-mentioned buck-boost sub-circuit 20 can be any circuit capable of boosting or bucking the voltage input by the power supply, for example: the above-mentioned buck-boost sub-circuit 20 can be composed of the switch tube S1, A buck-boost conversion circuit composed of the switch tube S2 , the diode D1 , the diode D2 , the capacitor C1 , the capacitor C2 , and the inductor L, etc., is not limited here.

In addition, the above-mentioned output parameter value can be the real-time output voltage value or real-time output current value of each LDO40; and the above-mentioned detection control subcircuit 30 can be any real-time output voltage value or real-time output current value that can detect each LDO40 to detect, according to The real-time output voltage value or real-time output current value of N LDO40 obtains the corresponding target voltage value, and controls the circuit whose output voltage value of the buck-boost sub-circuit 20 is greater than or equal to the target voltage value.

For example, the detection control sub-circuit 30 can be a control chip provided with control pins and N current/voltage detection pins, and the control pins of the control chip are connected to the buck-boost sub-circuit 20, different current The /voltage detection pin is connected to the output terminals of different LDO40; or, the detection control subcircuit 30 may also include a controller and N current/voltage sampling circuits connected in parallel to the controller, and the N current/voltage sampling circuits One-to-one correspondence with N LDO40, that is, different current/voltage sampling circuits are connected to the output terminals of different LDO40, and the current/voltage sampling circuit is used to collect the output current value/output voltage value of the LDO connected to it; the controller is used to determine the target voltage and control the adjustment of the minimum output voltage of the buck-boost sub-circuit 20, and so on.

Each of the above LDO40 is a linear voltage regulator device with a step-down voltage regulation function, which can use thin film transistors or field effect transistors operating in its linear region to subtract the excess voltage from the input voltage, that is, the voltage drop, to generate a regulated For example, each of the above LDO40 can be a low-dropout linear regulator with a cascode structure; or, it can also be a high-bandwidth low-dropout linear regulator, and so on.

As mentioned above, since the output voltage of LDO40 is obtained by subtracting the voltage difference from the input voltage, there is a linear relationship between the output parameter value of LDO40 and the input voltage value at its input terminal, that is, the input voltage value of LDO40 determines its output parameter value.

In a specific embodiment of the present invention, N is equal to 1, and the detection control subcircuit 30 is specifically configured to obtain a corresponding input voltage value according to the output parameter value, and determine the input voltage value as the target voltage value; or ,

N is greater than 1, and the detection control subcircuit 30 is specifically configured to obtain a corresponding input voltage value according to the output parameter value, and determine the maximum voltage value among the N input voltage values of the LDO40 as the target voltage value.

In this way, by determining the corresponding input voltage value according to the input parameter value of each LDO40, and then determining the target voltage value through the input voltage values of N LDO40, a more suitable target voltage value can be obtained, and the working stability of the load 200 can be further improved.

In addition, the above-mentioned detection control sub-circuit 30 can also select different ways to determine the target voltage value according to the number of LDO40 in the power supply circuit, that is, when only one LDO40 is included in the power supply circuit, the input voltage value of the LDO40 is determined as the above-mentioned target voltage value and when the power supply circuit includes a plurality of LDO40, the maximum voltage value among the input voltage values of the plurality of LDO40 is determined as the target voltage value, so that the power supply circuit can determine a more suitable target voltage value in different application scenarios.

In this embodiment, the detection and control sub-circuit 30 determines the corresponding input voltage value according to the output parameter values of N LDO40. It may be that the detection and control sub-circuit 30 detects the real-time output voltage value of N LDO40, and the real-time The sum of the output voltage value and its preset voltage difference is used as the input voltage value of the LDO40.

However, in the actual working process of the above-mentioned power supply circuit, when the above-mentioned output parameter value is a real-time output voltage value, the real-time output voltage needs to be output to the corresponding load through the line, and in the process of power transmission, the line will have power consumption. As a result, the actual input voltage value of the load is smaller than the corresponding real-time output voltage value of the LDO40, so that the determined input voltage value of the LDO40 may be too small, which may lead to a decrease in the working performance of some loads during normal operation.

In a specific embodiment of the present invention, the output parameter value of the LDO40 may be the real-time output current value of the LDO40, then, the detection control sub-circuit 30 determines the corresponding input voltage value according to the real-time output current values of the N LDO40s. Since the current signal has the characteristics of no line loss and no attenuation during transmission under the premise that the load meets the requirements, for each LDO40, the target voltage value determined by the real-time output current value is compared with the real-time output voltage value The determined input voltage value is more appropriate, not only can make each load work normally, but also can ensure the good working performance of each load.

As mentioned above, the detection and control sub-circuit 30 can determine the corresponding input voltage value according to the real-time output current of N LDO40, specifically, the detection and control sub-circuit 30 can also be used to determine the corresponding input voltage value according to the real-time output current value of the LDO40, And the corresponding relationship between the preset output current value and the input voltage value to obtain the input voltage value of the LDO.

Wherein, the detection and control subcircuit 30 obtains the input voltage value of the LDO40 according to the real-time output current value of the LDO40 and the preset corresponding relationship between the output current value and the input voltage value, and the detection and control subcircuit 30 passes the preset The corresponding relationship between the input current value and the input voltage value can quickly determine the input voltage value corresponding to the real-time output current value of each LDO40, and the boost detection control sub-circuit 30 controls the buck-boost sub-circuit 20 to adjust its output voltage response speed.

For example, if a plurality of preset output current values are stored in the storage device of the detection control subcircuit 30, and an input voltage value is preset corresponding to each preset output current value, the detection control subcircuit 30 can The input voltage value corresponding to the preset output current value closest to the real-time output current value of each LDO40 is determined as the input voltage value of the LDO40; or, the storage device may store multiple groups of adjacent output currents range value, and for each output current range value preset an input voltage corresponding to it, then the detection control subcircuit 30 can determine the input voltage value corresponding to the output current range value where the real-time output current value of each LDO40 is located. is the input voltage value of the LDO40, and so on.

During the working process of the LDO40, a corresponding maximum load current I _max is set for each LDO40, and the real-time output current I of the LDO40 is kept at the maximum load current, so as to maintain the normal operation of the corresponding load. However, since its real-time output current I will fluctuate with load fluctuations, that is, I is not equal to I _max . The actual input-output voltage difference V _dropout required by LDO40 to maintain a stable output voltage is,

V _dropout = (I/I _max )×V _dropoutmax ,

Among them, V _dropoutmax is the preset maximum input-output pressure drop of the LDO.

It can be seen that when the fluctuation of I is smaller than the maximum load current I _max , the actual input-output voltage difference V _dropout is smaller than the preset maximum input-output voltage difference V _dropoutmax . And if the LDO40 works according to the preset maximum input-output voltage difference V _dropoutmax , and because the circuit usually uses the sum of the preset output voltage value V _out of the LDO40 and the preset maximum input-output voltage difference V _dropoutmax , it is preset as the LDO40 The input voltage value of the LDO40 causes the actual output voltage value of the LDO40 to be greater than the preset input voltage value V _out , thereby increasing the input voltage of the corresponding load 200 and increasing the power loss of the corresponding load 200 , resulting in an increase in power consumption of the terminal equipment. , especially when the maximum load current of the LDO40 is relatively large and the real-time output current is relatively small, it will consume more electric energy.

In a specific embodiment of the present invention, the detection control sub-circuit 30 can also be used to calculate the actual input and output pressure difference of the LDO40, and determine the sum of the preset output voltage value of the LDO40 and the actual input and output pressure difference is the target voltage value; wherein, the actual input-output pressure difference is the product of the ratio of the real-time output current value of the LDO40 to the preset maximum load current value and the preset maximum input-output pressure difference.

That is, the detection control sub-circuit 30 can calculate the input voltage value of each LDO 40 according to the following calculation formula:

V _in =V _out +(I/I _max )×V _dropoutmax ,

Among them, V _in represents the input voltage value of LDO40;

V _out represents the preset output voltage value of LDO40;

I represents the real-time output current value of LDO40;

I _max represents the preset maximum load current value of LDO40;

V _dropoutmax represents the preset maximum input and output pressure drop of LDO40;

In this way, the detection control sub-circuit 30 can calculate a more accurate input voltage value of each LDO 40 to make the output voltage of the buck-boost sub-circuit 20 more appropriate, thereby reducing power consumption and power consumption of terminal equipment.

The power supply circuit of the embodiment of the present invention includes a power supply, a buck-boost sub-circuit, a detection control sub-circuit, and N low-dropout linear regulators LDO; the input end of the buck-boost sub-circuit is connected to the power supply; the input end of the LDO is connected to the power supply The output terminals of the buck-boost sub-circuit are connected, and the output terminals of the LDO are connected to the corresponding loads; the detection control sub-circuit is used to detect the output parameter values of the N LDOs, and the output parameters satisfying the preset conditions are obtained according to the output parameter values of the N LDOs. The target voltage value, and control the output voltage value of the buck-boost sub-circuit to be greater than or equal to the target voltage value. In this way, the power supply circuit can adjust the minimum output voltage value of the buck-boost sub-circuit, that is, the minimum input voltage value of the N LDOs, to an appropriate voltage value according to the output parameter values of the N LDOs, thereby improving the voltage conversion efficiency of each LDO , so that the output voltage of each LDO meets the requirements of its corresponding load, and the working stability of the load is improved.

Based on the above power supply circuit, an embodiment of the present invention also provides a terminal device, including at least one load and the above power supply circuit, and the power supply circuit includes a power supply, a buck-boost sub-circuit, a detection control sub-circuit, and N LDOs, wherein:

The input end of the buck-boost sub-circuit is connected to the power supply;

The input terminals of the LDO are all connected to the output terminals of the buck-boost sub-circuit, and the output terminals of the LDO are connected to the corresponding load;

The detection and control sub-circuit is used to detect the output parameter values of the N LDOs, obtain the target voltage value satisfying the preset condition according to the output parameter values of the N LDOs, and control the output of the buck-boost sub-circuit The voltage value is greater than or equal to the target voltage value.

Since the structure of the terminal device itself is well known to those skilled in the art, and the specific structure of the power supply circuit has been described in the above embodiments, the specific structure of the terminal device will not be repeated here.

In the embodiment of the present invention, the above-mentioned terminal equipment may include: a mobile phone, a tablet computer (Tablet PersonalComputer), a laptop computer (Laptop Computer), a personal digital assistant (personal digital assistant, PDA for short), a mobile Internet device (Mobile Internet Device, MID ) or wearable devices (Wearable Device), etc.

Please refer to FIG. 3. FIG. 3 is a schematic flowchart of a power supply control method for a terminal device provided by an embodiment of the present invention. The terminal device includes a power supply circuit, and the power supply circuit includes a buck-boost sub-circuit and a detection control sub-circuit. And N low-dropout linear regulators LDO; N is a positive integer, as shown in Figure 3, the power supply control method of the terminal equipment includes the following steps:

Step 301, the detection control subcircuit detects the output parameter value of each LDO in the N LDOs;

Step 302, the detection and control sub-circuit obtains a target voltage value satisfying a preset condition according to the output parameter values of the N LDOs;

Step 303 , the detection control subcircuit controls the output voltage value of the buck-boost subcircuit to be greater than or equal to the target voltage value.

Optionally, the above step 302 includes:

N is equal to 1, and the detection control subcircuit obtains a corresponding input voltage value according to the output parameter value, and determines the input voltage value as the target voltage value; or,

N is greater than 1, the detection control subcircuit obtains a corresponding input voltage value according to the output parameter value, and the detection control subcircuit determines the maximum voltage value among the N input voltage values of the LDO as the target voltage value.

Optionally, the output parameter value of the LDO is a real-time output current value of the LDO.

Optionally, the step of obtaining the corresponding input voltage value by the detection control subcircuit according to the output parameter value includes:

The detection control sub-circuit obtains the input voltage value of the LDO according to the real-time output current value of the LDO and the preset correspondence between the output current value and the input voltage value.

Optionally, the step of obtaining the corresponding input voltage value by the detection control subcircuit according to the output parameter value includes:

The detection and control sub-circuit calculates the actual input-output voltage difference of the LDO, and determines the sum of the preset output voltage value of the LDO and the actual voltage difference as the target voltage value;

Wherein, the actual input-output voltage difference is the product of the ratio of the real-time output current value of the LDO to its preset maximum load current value and the preset maximum input-output voltage difference.

It should be noted that this embodiment is an implementation manner corresponding to the power supply circuit in the above embodiment, and its specific implementation manner can refer to the relevant description of the above embodiment. achieve the same beneficial effect.

Embodiments of the present invention have been described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementations, and the above-mentioned specific implementations are only illustrative, rather than restrictive, and those of ordinary skill in the art will Under the enlightenment of the present invention, without departing from the gist of the present invention and the protection scope of the claims, many forms can also be made, all of which belong to the protection of the present invention.

Claims (11)

1. A power supply circuit, characterized in that, the power supply circuit comprises a power supply, a buck-boost sub-circuit, a detection control sub-circuit, and N low-dropout linear regulators LDO, where N is a positive integer, wherein: The input end of the buck-boost sub-circuit is connected to the power supply; The input end of the LDO is connected to the output end of the buck-boost sub-circuit, and the output ends of the LDO are respectively connected to corresponding loads; The detection and control sub-circuit is used to detect the output parameter values of the N LDOs, obtain the target voltage value satisfying the preset condition according to the output parameter values of the N LDOs, and control the output of the buck-boost sub-circuit The voltage value is greater than or equal to the target voltage value. 2. The power supply circuit according to claim 1, wherein N is equal to 1, and the detection control subcircuit is specifically used to obtain a corresponding input voltage value according to the output parameter value, and determine the input voltage value is the target voltage value; or, N is greater than 1, and the detection control subcircuit is specifically configured to obtain a corresponding input voltage value according to the output parameter value, and determine the maximum voltage value among the N input voltage values of the LDOs as the target voltage value. 3. The power supply circuit according to claim 1 or 2, wherein the output parameter value of the LDO is a real-time output current value of the LDO. 4. The power supply circuit according to claim 3, wherein the detection and control sub-circuit is specifically configured to correspond to the real-time output current value of the LDO and the preset output current value and input voltage value relationship to get the input voltage value of the LDO. 5. The power supply circuit according to claim 3, wherein the detection control sub-circuit is specifically configured to calculate the actual input-output voltage difference of the LDO, and compare the preset output voltage value of the LDO with the actual input The sum of output voltage differences is determined as the target voltage value; wherein, the actual input and output pressure difference is the ratio of the real-time output current value of the LDO to the preset maximum load current value, and the preset maximum input and output voltage The product of the differences. 6. A terminal device comprising at least one load, characterized in that the terminal device further comprises the power supply circuit according to any one of claims 1 to 5, the power supply circuit comprising a power supply, a buck-boost sub-circuit , detection and control sub-circuit and N low-dropout linear regulators LDO, wherein: The input end of the buck-boost sub-circuit is connected to the power supply; The input end of the LDO is connected to the output end of the buck-boost sub-circuit, and the output end of the LDO is connected to a corresponding load; The detection and control sub-circuit is used to detect the output parameter values of the N LDOs, obtain the target voltage value satisfying the preset condition according to the output parameter values of the N LDOs, and control the output of the buck-boost sub-circuit The voltage value is greater than or equal to the target voltage value. 7. A power supply control method for terminal equipment, which is applied to the terminal equipment according to claim 6, wherein the terminal equipment includes a power supply circuit, and the power supply circuit includes a power supply, a buck-boost sub-circuit, a detection Control sub-circuits and N low-dropout linear regulators LDO; N is a positive integer, and the power supply control method of the terminal equipment includes: The detection and control subcircuit detects the output parameter values of the N LDOs; The detection control sub-circuit obtains a target voltage value satisfying a preset condition according to output parameter values of the N LDOs; The detection control subcircuit controls the output voltage value of the step-down subcircuit to be greater than or equal to the target voltage value. 8. The power supply control method for terminal equipment according to claim 7, wherein the step of obtaining the target voltage value satisfying the preset condition according to the output parameter values of the N LDOs by the detection control sub-circuit comprises: N is equal to 1, and the detection control subcircuit obtains a corresponding input voltage value according to the output parameter value, and determines the input voltage value as the target voltage value; or, N is greater than 1, the detection control subcircuit obtains a corresponding input voltage value according to the output parameter value, and the detection control subcircuit determines the maximum voltage value among the N input voltage values of the LDO as the target voltage value. 9. The power supply control method for terminal equipment according to claim 8, wherein the output parameter value of the LDO is a real-time output current value of the LDO. 10. The power supply control method for terminal equipment according to claim 9, wherein the step of obtaining the corresponding input voltage value according to the output parameter value by the detection control sub-circuit comprises: The detection control sub-circuit obtains the input voltage value of the LDO according to the real-time output current value of the LDO and the preset correspondence between the output current value and the input voltage value. 11. The power supply control method for terminal equipment according to claim 9, wherein the step of obtaining the corresponding input voltage value according to the output parameter value by the detection control sub-circuit comprises: The detection and control sub-circuit calculates the actual input-output voltage difference of the LDO, and determines the sum of the preset output voltage value of the LDO and the actual voltage difference as the target voltage value; Wherein, the actual input-output voltage difference is the product of the ratio of the real-time output current value of the LDO to its preset maximum load current value and the preset maximum input-output voltage difference.