WO2018120214A1

WO2018120214A1 - Method for adjusting energy efficiency of power supply of terminal and terminal

Info

Publication number: WO2018120214A1
Application number: PCT/CN2016/113938
Authority: WO
Inventors: 陈敏
Original assignee: 华为技术有限公司
Priority date: 2016-12-30
Filing date: 2016-12-30
Publication date: 2018-07-05
Also published as: CN108702091B; CN108702091A

Abstract

A method for adjusting the energy efficiency of a power supply of a terminal and the terminal, related to the field of circuits, allowing, in a scenario in which an LDO is connected after a DC-DC voltage converter (1), quick configuration of an output voltage of the DC-DC voltage converter when a change occurs in the state of the LDO, thus allowing a voltage drop (VDS) on an LDO power transistor to be maintained at a critical voltage of a saturated area and of a linear area, and ensuring the energy efficiency of a power supply system of the terminal. The method comprises: a terminal determines N LDO in a powered on state of at least one LDO connected to a voltage converter, N being an integer greater than or equal to 1; and the terminal configures an output voltage of the voltage converter on the basis of state information of the N LDO. The state information comprises a load current or an output voltage.

Description

Method and terminal for adjusting energy efficiency of terminal power supply

Technical field

The present invention relates to the field of circuits, and in particular, to a method and terminal for adjusting energy efficiency of a terminal power supply.

Background technique

At present, in order to improve the efficiency of the mobile phone power system, the battery of the mobile phone is usually connected to a DC (Direct Current, DC power)-DC converter output and then connected to an LDO (Low Dropout Regulator).

Wherein, when the LDO power tube operates in the saturation region, the load current of the LDO no longer changes according to the voltage drop on the LDO power tube, and the voltage drop on the LDO power tube may increase when the load current of the LDO is constant. Large voltage drops can cause heating problems that affect the efficiency of the power system. When the LDO power tube operates in the linear region, the load current of the LDO decreases as the voltage drop across the LDO power tube decreases. The voltage drop across the LDO power tube is too small, and the stability and overall performance of the LDO will decrease. Only the LDO operates at the boundary between the saturation region and the linear region (ie, the voltage drop across the LDO power transistor maintains the threshold voltage in the saturation region and the linear region) to achieve the highest efficiency while ensuring LDO performance. Since the DC-DC voltage converter is connected in series with the LDO, the output voltage of the DC-DC voltage converter is the sum of the voltage drop across the LDO power tube and the output voltage of the LDO. Therefore, the output of the DC-DC voltage converter is set. The voltage drop across the LDO is taken into account so that the voltage drop across the LDO is maintained in the saturation region.

In the prior art, the integrated circuit implementation method is adopted, and the DC-DC voltage converter and the LDO are put together for unified control. As shown in Figure 1 (taking the DC-DC variator as BUCK as an example), the output voltage of the BUCK can be adaptively adjusted according to the load current of the LDO, and the LDO's MP tube (ie, the power tube of the LDO) is always operated linearly. The critical point of the zone and the saturation zone ensures good performance of the LDO and thus improves the energy efficiency of the entire power system.

However, in the scheme shown in Figure 1, BUCK and LDO are combined to form a loop. The BUCK and the LDO each form a loop. Once the load current of the LDO changes, it will cause synchronous adjustment of each loop (including the loop composed of BUCK and LDO, BUCK loop and LDO loop) to adjust the output voltage of BUCK so that the voltage drop across the LDO is maintained. The threshold voltage of the saturation region and the linear region. You can only use DCDC to connect to an LDO. The principle of this method is to adjust DCDC and LDO as a whole. For DCDCs connected to multiple LDOs, multiple loops cannot be adjusted at the same time.

Summary of the invention

Embodiments of the present invention provide a method and a terminal for adjusting energy efficiency of a terminal power supply. In a scenario where a DC-DC voltage converter is connected to an LDO, when the state of the LDO changes, the load current or output voltage of the LDO can be quickly obtained. Setting the output voltage of the DC-DC voltage converter ensures the energy efficiency of the terminal power system.

In order to achieve the above object, embodiments of the present invention adopt the following technical solutions:

In a first aspect, a method for adjusting energy efficiency of a terminal power supply is disclosed, which is applied to a terminal, the terminal comprising a power source, a voltage converter connected to the power source, at least one low-dropout linear regulator LDO connected to the voltage converter, and a voltage The processor to which the converter is connected. The method includes: the terminal determining N LDOs in a power-on state in at least one LDO, where N is an integer greater than or equal to 1. Subsequently, the terminal sets an output voltage of the voltage converter according to state information of the N LDOs, wherein the state information includes a load current and/or an output voltage.

It can be seen that when the voltage converter connected to the power supply of the terminal is connected to multiple LDOs, the terminal can quickly set the output voltage of the DC-DC voltage converter according to the output voltage or load current of the LDO. It can be seen that when the state of the LDO changes, the terminal can quickly acquire the output voltage or load current of the LDO, and thus can quickly set the output voltage of the DC-DC voltage converter according to the output voltage or load current of the LDO to ensure the terminal power system. efficient.

With reference to the first aspect, in a first possible implementation manner of the first aspect, if N is greater than or equal to 2, setting, by the terminal, the output voltage of the voltage converter according to the state information of the N LDOs includes: reading in a register of the terminal Take the output voltage of N LDOs and Working pressure drop, obtaining the maximum working voltage drop of the first target LDO; where the operating voltage drop is the voltage drop when the LDO is in the power-on state; setting the output voltage of the voltage converter equal to the maximum operating voltage drop of the first target LDO The sum of the output voltages of the first target LDOs, wherein the first target LDO is the LDO having the largest output voltage among the N LDOs.

It can be seen that, in the method provided by the present application, when the voltage converter is connected to multiple LDOs, the terminal can determine a target LDO according to the output voltage of each LDO connected after the voltage converter, and thus can obtain the maximum operating voltage drop according to the target LDO. To quickly set the output voltage of the voltage converter, when the state of the plurality of LDOs is changed, the output voltage of the voltage converter is quickly set, so that the energy efficiency of the terminal power system is high. Here, the output voltages of the plurality of LDOs may be the same or different.

With reference to the first aspect, in a second possible implementation manner of the first aspect, if N is greater than or equal to 2 and the output voltages of the N LDOs are the same, the terminal sets the output voltage of the voltage converter according to the state information of the N LDOs. The method includes: acquiring a first threshold voltage corresponding to a load current of the second target LDO, where the first threshold voltage is a voltage corresponding to a critical position of the second target LDO operating in the linear region and the saturation region; setting an output voltage of the voltage converter to be equal to the second The sum of the output voltage of the target LDO and the threshold voltage, wherein the second target LDO is the LDO with the largest load current among the N LDOs.

It can be seen that, in the method provided by the present application, when the voltage converter is connected to a plurality of LDOs and the output voltages of the LDOs are the same, the target LDO can be determined according to the magnitude of the load current of the LDO, and then the output voltage of the target LDO in the register can be The threshold voltage corresponding to the load current of the target LDO quickly sets the output voltage of the voltage converter. When the state of the plurality of LDOs is changed, the output voltage of the voltage converter is quickly set, so that the energy efficiency of the terminal power system is high.

With reference to the first aspect, in a third possible implementation manner of the first aspect, if N is 1, the setting, by the terminal, the output voltage of the voltage converter according to the state information of the N LDOs includes: determining, by the terminal, the third target LDO a first load current; the third target LDO is an LDO that is the only power-on state in at least one LDO; acquiring the first load current

a second threshold voltage corresponding to the value; the second threshold voltage is a voltage corresponding to the third target LDO operating at a critical point of the linear region and the saturation region at the first load current; setting the voltage The output voltage of the converter is equal to the sum of the output voltage of the third target LDO and the first threshold voltage.

In the method provided by the present application, when the voltage converter is followed by an LDO, the output voltage of the voltage converter can be quickly set according to the threshold voltage corresponding to the load current of the LDO and the output voltage of the LDO, followed by an LDO. When the state changes, the output voltage of the voltage converter is quickly set to ensure the high efficiency of the terminal power system.

In conjunction with the third possible implementation of the first aspect, in a fourth possible implementation manner of the first aspect, the terminal determines that an output voltage of the voltage converter is equal to a sum of an output voltage of the third target LDO and a second threshold voltage After the method, the method further includes: the terminal detects that the first load current is reduced to the second load current, and determines a load current interval where the second load current is located; if the load current interval where the second load current is located and the load where the first load current is located The current interval is different, and the third threshold voltage corresponding to the load current interval where the second load current is located is obtained; and the output voltage of the set voltage converter is equal to the sum of the third threshold voltage and the output voltage of the third target LDO.

In the method provided by the present application, when the voltage converter is connected to an LDO, the output voltage of the voltage converter can be quickly set according to the change of the LDO load current from large to small, thereby ensuring high efficiency of the terminal power system.

In conjunction with the third or fourth possible implementation of the first aspect, in a fifth possible implementation manner of the first aspect, the terminal determines that an output voltage of the voltage converter is equal to that of the third target LDO After the sum of the output voltage and the second threshold voltage, the method further includes: if the terminal monitors that the output voltage of the third target LDO is lower than a threshold threshold, determining whether the output voltage of the third target LDO is And increasing the output voltage of the voltage converter until the output voltage of the third target LDO is lower than the threshold threshold for a preset period of time; The output voltage of the three-target LDO is no longer below the threshold threshold.

When the voltage converter is connected to an LDO, the output voltage of the voltage converter can be set according to the load current and output voltage of the LDO to ensure high efficiency of the terminal power system.

In a second aspect, a terminal is disclosed, including: a processor, a power supply, and a voltage conversion And M low-dropout linear regulators LDO, M is an integer greater than or equal to 1. The connection relationship between the various circuits is as follows: the voltage converter is connected to the power supply and is also connected to the processor, and the voltage converter is connected to the M LDOs.

The processor is configured to determine N LDOs in a power-on state of the M LDOs, where N is an integer greater than or equal to 1, and set an output voltage of the voltage converter according to state information of the N LDOs. It should be noted that the status information is load current and or output voltage.

With reference to the second aspect, in a first possible implementation manner of the second aspect, the LDO specifically includes a power tube, and an input end of the power tube is connected to an output end of the voltage converter, and an output voltage of the power tube is an output voltage of the LDO. If N is greater than or equal to 2, the processor is specifically configured to obtain output voltages of the N power tubes included in the N LDOs, obtain a maximum operating voltage drop of the first target LDO, and set an output voltage of the voltage converter to be equal to the first target LDO. The maximum operating voltage drop is the sum of the output voltage of the first target LDO; the operating voltage drop is the voltage drop when the first target LDO is in the power-on state, and the first target LDO is the LDO with the largest output voltage.

Or, if the output voltages of the N LDOs are the same, acquiring a first threshold voltage corresponding to the load current of the second target LDO, and setting an output voltage of the voltage converter equal to a sum of an output voltage of the second target LDO and the first threshold voltage; The first threshold voltage is a voltage corresponding to the load current of the second target LDO at a critical point of the linear region and the saturation region; wherein the second target LDO is the load current of the N power transistors included in the N LDOs LDO.

With reference to the second aspect, in a second possible implementation manner of the second aspect, the LDO specifically includes a power tube, and an input end of the power tube is connected to an output end of the voltage converter, and an output voltage of the power tube is an output voltage of the LDO. If N is 1, the processor is specifically configured to: determine a first load current of the third target LDO; acquire a second threshold voltage corresponding to the first load current value; and the second threshold voltage is a third target LDO with the first load current The voltage corresponding to the critical region of the linear region and the saturation region; the third target LDO is the LDO that is the only power-on state among the M LDOs; the processor is further configured to set the output voltage of the voltage converter to be equal to the third target LDO The output voltage of the power tube (ie the third target in the register) The output voltage of the LDO is the sum of the second threshold voltage.

In conjunction with the second possible implementation of the second aspect, in a third possible implementation manner of the second aspect, the third target LDO further includes: a feedback circuit, a first judgment comparison circuit, where the power An output end of the tube is connected to an input end of the feedback circuit, an output end of the feedback circuit is connected to an input end of the first judgment comparison circuit, and an output end of the first judgment comparison circuit is connected to the processor The feedback circuit is configured to: if it is determined that the output voltage of the power tube of the third target LDO is lower than the threshold threshold, instruct the first judgment comparison circuit to determine the output of the power tube of the third target LDO Whether the voltage is lower than the threshold threshold for a preset period of time; if the first judgment comparison circuit determines that the output voltage of the power tube of the third target LDO is consistently lower than the threshold threshold for the preset duration Transmitting, to the processor, a first interrupt, the first interrupt is used to instruct the processor to increase an output voltage of the voltage converter, and the processor is configured to increase the voltage conversion Output voltage, said third target until the LDO output voltage is no longer below the threshold value threshold.

In conjunction with the second or third possible implementation of the second aspect, in a first possible implementation of the second aspect, the third target LDO further includes a current sensing circuit; wherein the power tube input The end is connected to the output end of the voltage converter, and the output end of the current sensing circuit is connected to the processor; the current sensing circuit is configured to monitor a change of the first load current; if the current The sensing circuit detects that the first load current is changed from large to small, and then sends a second interrupt to the processor; the second interrupt is used to indicate the second load current; and the processor is configured to determine the a load current interval in which the second load current is located, if the load current interval in which the second load current is located is different from the load current interval in which the first load current is located, acquiring a load current interval in which the second load current is located a third threshold voltage; the processor is further configured to set an output voltage of the voltage converter equal to an output voltage of the power tube of the third target LDO and the third threshold And the pressure.

DRAWINGS

FIG. 1 is a circuit diagram of adjusting energy efficiency of a power supply of an existing terminal;

2 is a circuit diagram of a DC-DC voltage converter connected to a mobile phone power supply;

3 is a circuit diagram of a conventional LDO;

Figure 4 is a schematic diagram of voltage-current during operation of the LDO;

FIG. 5 is an internal circuit diagram of a terminal according to an embodiment of the present invention;

FIG. 6 is another internal circuit diagram of a terminal according to an embodiment of the present invention;

FIG. 7 is a schematic flowchart of a method for adjusting energy efficiency of a terminal power supply according to an embodiment of the present invention;

FIG. 8 is another internal circuit diagram of a terminal according to an embodiment of the present invention;

FIG. 9 is another internal circuit diagram of a terminal according to an embodiment of the present invention;

10 is another schematic flowchart of a method for adjusting energy efficiency of a terminal power supply according to an embodiment of the present invention;

Figure 11 is a schematic diagram of the operating voltage drop across the LDO and the voltage across it;

Figure 12 is a schematic diagram showing the relationship between the LDO load current and the threshold voltage.

detailed description

At present, the mobile phone power system needs to set the LDO to achieve the voltage regulation effect. At the same time, in order to improve the efficiency of the mobile phone power supply, you can connect the DC-DC voltage converter (such as BUCK or BUCK-BOOST) to the LDO. The efficiency here refers to the battery (ie mobile phone power) power utilization. If the DC-DC voltage converter is not used to step down, the battery voltage is higher, such as 4V, and the LDO output voltage is lower, such as 1.2V. If the LDO is directly connected to the battery, the LDO's power tube MP has a voltage drop of 4-1.2 = 2.8V. If the DC-DC voltage converter is stepped down, the DC-DC voltage converter can output, for example, 1.5V, so that the LDO's power tube MP is only 1.5-1.2=0.3V, which can improve the battery life. The DC-DC voltage converter, and the LDO, can each be an integrated circuit.

The connection relationship between the mobile phone power supply, the DC-DC voltage converter and the LDO is shown in Fig. 2. The DC-DC voltage converter is connected to the mobile phone power supply, the DC-DC voltage converter output is connected to the LDO, and the LDO is connected in series. Typically, the output voltage (DCDC_V _out ) of the DC-DC voltage converter is set to account for the voltage drop across the LDO. Referring to FIG. 2, the voltage drop VDS on the LDO power transistor is (DC-DC_V _out )-(LDO_V _out ), which is the difference between the output voltage of the DC-DC voltage converter and the output voltage of the LDO.

As shown in Figure 3, the LDO typically includes a power tube. Wherein, the power tube can be MOS (metal-oxid-semiconductor, metal-oxide-semiconductor) tube. The power tube includes a first end, a second end, and a third end. The first end of the power tube is an input end, and is connected to an output end of the DC-DC voltage converter; the second end of the power tube is an output end, and the load is connected. The load can be a camera component, a display device, etc.; the third end of the power tube can be connected to the processor according to circuit design requirements, or connected to other circuits. When the power tube is an N-type MOS tube, the second end of the power tube is the load current of the source LDO, that is, the current on the source of the MOS tube, and the output voltage of the LDO is the voltage on the source of the MOS tube. When the power transistor is a P-type MOS transistor, that is, the second end of the power transistor is a drain, the load current of the LDO is the current on the drain of the MOS transistor, and the output voltage of the LDO is the voltage on the drain of the MOS transistor.

Referring specifically to FIG. 3, the power tube is a P-type MOS transistor, and the input end (source) of the power tube is connected to the output end of the DC-DC voltage converter, and the output end (drain) of the power tube is connected to the load. It should be noted that, in the embodiment of the present invention, the operating voltage drop of the LDO, that is, the voltage drop on the power tube in the LDO when the LDO is in the power-on state.

As shown in Figure 4, it is a voltage-current diagram when the LDO is operating. The voltage here refers to the operating voltage drop of the LDO, and the current refers to the load current of the LDO. The working state of the LDO can be divided into a linear region and a saturated region. When in the linear region, the voltage drop VDS on the LDO power transistor is linear with the load current I of the LDO, and the load current I increases as the voltage drop VDS increases. When in the saturation region, the voltage drop VDS and the load current are no longer linear, and as the voltage drop VDS continues to increase, the load current I remains almost unchanged. When the VDS is too low and the LDO enters the linear region, the LDO stability and immunity will decrease. When the VDS is too high, the LDO enters the saturation region, the load current is I ₀ remains unchanged, and the power consumed on it I ₀ *VDS is completely used for heat generation, which reduces system efficiency and causes heat generation. Therefore, it is necessary to dynamically adjust the VDS (DC-DC_V _out )-(LDO_V _out ) according to the working condition of the LDO to ensure that the LDO operates in the saturation region and the voltage drop on the power tube is the smallest, that is, the threshold voltage V ₀ in FIG. 3 (is the LDO) The voltage corresponding to the critical region of the linear region and the saturation region).

In the prior art, the DC-DC voltage converter and the LDO are collectively controlled together in one integrated circuit. Referring to Figure 1, wherein C, C ₀ are capacitors and R ₀ is a resistor. The DC-DC voltage converter duty cycle is controlled by the output of the LDO's error amplifier (related to the input voltage, output voltage, and load current of the DC-DC voltage converter). Thus, the output voltage of the DC-DC converter is no longer a fixed value, the interior loop may be adjusted in accordance with the load current V _out and the system voltage of the LDO. The deviation of V _out is adjusted by controlling the duty cycle of the DC-DC voltage converter, so that (V _Buck -V _out ) is adjusted to approximate the threshold voltage of the LDO, so that the LDO's MP tube is always operated in the linear region and the saturation region. The critical point of this ensures the good performance of the LDO, which in turn increases the energy efficiency of the entire power system.

Since this method is to adjust a DC-DC voltage converter and an LDO as a whole, the DC-DC voltage converter and the LDO are combined to form a loop. Once the load current of the LDO changes, DC-DC is caused. V _Buck will change when the voltage converter loop changes. To ensure that the LDO's MP tube works at the critical point of the linear region and the saturation region, it is necessary to readjust V _out to maintain the voltage drop across the LDO's MP tube. The threshold voltage (ie the voltage at the critical point of the linear and saturated regions). It can be seen that the synchronous adjustment of the DC-DC voltage converter loop is caused, resulting in a low adjustment bandwidth and a slow speed of the entire loop. At the same time, for the scene where the DC-DC voltage converter is connected to multiple LDOs, this method cannot adjust multiple loops at the same time. Therefore, this method is only applicable to the scene where the DC-DC voltage converter is followed by an LDO.

The principle of the embodiment of the present invention is: when the DC-DC voltage converter is connected to a plurality of LDOs, the input voltage of the LDO pre-stage, that is, the output of the DC-DC voltage converter is set according to the LDO with the largest output voltage or the LDO with the largest load current. Voltage. When the DC-DC voltage converter is followed by an LDO, the output voltage of the DC-DC voltage converter is set according to the change of the LDO load current. That is to say, the output voltage of the LDO pre-stage is dynamically adjusted following the state of the LDO, so that the respective loops of the DC-DC voltage converter and the LDO are separately adjusted, and the respective stability adjustments of the DC-DC voltage converter and the LDO remain unchanged. When the state of some LDOs changes (the load condition changes or the number of LDOs connected changes), the output voltage value of the DC-DC voltage converter can be quickly set, so that the voltage drop on the LDO remains stable without affecting the whole. The energy efficiency of the power system.

Example 1:

An embodiment of the present invention provides a terminal. As shown in FIG. 5, the terminal includes a circuit for adjusting power efficiency of the terminal, and the circuit is connected to a power source of the terminal. As shown in Figure 5, The circuit includes a voltage converter 1, M LDOs 2 (LDO 1 - LDO M in the figure), and a processor 3; wherein the voltage converter 1 can be a DC-DC voltage converter converter, and the processor 3 can be CPU (Central Processing Unit) of the terminal.

Referring to FIG. 5, the voltage converter 1 includes a first end 11, a second end 12, and M third ends 13. The first end 11 is connected to the power supply of the terminal, the second end 12 is connected to the processor 3, and the M third ends 13 are respectively connected to the M LDOs, that is, each LDO connected after the voltage converter 1 is connected to the first one. The three terminals 13 and the third terminal 13 are the output terminals of the voltage converter.

In addition, the processor 3 is connected at one end to the second end 12 of the voltage converter 1 and at the other end to the power supply of the terminal.

Further, referring to FIG. 6, the LDO includes a power tube 21. Referring specifically to FIG. 3, the source 210 of the power tube is connected to the voltage converter 1, and the drain 211 of the power tube is connected to the load. The gate 212 of the power tube is coupled to the processor 3.

It should be noted that the circuits shown in FIG. 5 and FIG. 6 need to meet the following conditions:

1. When the output voltage of the voltage converter is equal to the sum of the output voltage of the target LDO and the operating voltage drop of the target LDO, or equal to the sum of the threshold voltage corresponding to the load current of the target LDO and the output voltage of the target LDO, because the voltage is transformed at this time. The output voltage of the device is already low to the limit allowed by the LDO, so the load capacitance of the voltage converter needs to be able to provide sufficient energy (generated by the capacitor discharge) when the LDO is transiently responsive so that the output voltage of the LDO does not occur instantaneously. reduce. That is to say, if the load of the LDO becomes larger, the VDS of the LDO needs to be larger. If the output voltage of the voltage converter does not increase, then the voltage to be increased by the VDS comes from the capacitor discharge of the voltage converter, and the voltage conversion is required. The capacitance of the device is large enough to supply enough VDS to the LDO, and the output voltage of the LDO does not drop.

2. The OCP (Over Current Protection) time of the LDO is faster than the current limit response time of the voltage converter. This is because when the load current of the LDO becomes large, if the OCP time of the LDO is too slow, a large current is drawn from the voltage converter. Voltage converter output large current flows through the above LDO, then voltage conversion The remaining drive capacity of the device is very small, and it is no longer possible to drive other LDOs, which may cause the voltage converter to enter the OCP protection state. At this time, the voltage converter cannot provide load capacity to other LDOs, and the system may be powered off or enter an error state.

In a specific implementation, the circuit shown in FIG. 5 or FIG. 6 can be used to implement the method for adjusting the energy efficiency of the terminal power supply provided in this embodiment. As shown in FIG. 7, the method includes the following steps:

101. The processor determines N LDOs in a power-on state among the M LDOs; the N is an integer greater than or equal to 2.

In a specific implementation, the output voltage of the voltage converter is set in the state of the LDO (such as the output voltage or the load current) in all working states (ie, the power-on state described in the embodiment of the present invention), for the connection only After the voltage converter, but the unpowered LDO is not considered. Therefore, firstly, the LDO in the power-on state of the LDO connected to the DCD can be determined. In addition, the method provided in this embodiment is applicable to a scenario in which at least two LDOs are in a powered state.

102. The processor determines an LDO with a maximum output voltage of the N LDOs as a first target LDO.

That is, the LDO having the largest output voltage in the LDO in the power-on state is determined as the first target LDO.

In a specific implementation, the output voltage of the LDO may be the actual output voltage of the LDO when the LDO is in a steady state, or may be the output voltage setting value of the LDO in the register of the terminal. The output voltages of N LDOs are quite different, such as 1.2V, 1.8V, 1.9V, etc. In order to meet the load capacity requirements of all LDOs at the same time, the output voltage of the voltage converter is determined by the LDO of the highest voltage value and its load condition. .

For example, the voltage value of the LDO output, which is the real-time output voltage of the LDO, can be obtained by the sampling circuit in real time. The actual output voltage of the LDO can also be stored in the register or memory of the terminal and updated in real time. .

It should be noted that, in a specific implementation, the output voltage of each LDO and the operating voltage drop of each LDO can be stored in a register (or memory) of the terminal. Before step 102, the processor first registers (or memory) in the terminal. Reading each LDO Configuration parameters, such as: output voltage, operating voltage drop, etc. The first target LDO is further determined therein according to the configuration parameters of the respective LDOs.

103. The processor sets an output voltage of the voltage converter according to an output voltage of the first target LDO.

Specifically, the maximum operating voltage drop of the first target LDO is determined, where the operating voltage drop refers to the voltage drop when the LDO is in the powered state, that is, the VDS (or V _dropout ) in FIG. In addition, an LDO may be provided with a set of operating pressure drops, where the maximum operating pressure drop is the maximum of the set of operating pressure drops.

Further, an output voltage of the voltage converter is set according to a maximum operating voltage drop of the first target LDO and an output voltage of the first target LDO.

Specifically, the processor writes an output voltage of the voltage converter in the register, and an output voltage of the voltage converter is equal to a sum of a maximum operating voltage drop of the first target LDO and an output voltage of the first target LDO, an example , DCDC_V _out ) is equal to (V _LDO,max +V _dropout,max ), wherein V _dropout,max is the maximum operating pressure drop of the first target LDO according to the embodiment of the present invention, and V _LDO,max is the implementation of the present invention. The output voltage value of the LDO with the largest output voltage as described in the example.

Preferably, if the output voltage values of the LDOs followed by the LDOs are the same, that is, the output voltages of the N LDOs are the same, the output voltage of the voltage converter can be set according to the load current of the LDO. At this time, it is determined that the LDO having the largest load current among the N LDOs in the power-on state is the second target LDO. The load current of the LDO can be obtained in real time through the sampling circuit.

Specifically, the output voltage of the voltage converter can be set by: determining a threshold voltage corresponding to a load current of the second target LDO, where the threshold voltage is a voltage corresponding to a critical point of the second target LDO operating in the linear region and the saturation region, that is, The second target LDO operates at the critical point of the linear and saturation regions (ie, the operating voltage drop across the LDO power tube). Thereafter, the processor can determine that the output voltage of the voltage converter is equal to the sum of the output voltage of the second target LDO and the threshold voltage.

In a preferred embodiment of the present invention, the method further includes: the processor monitoring a power-on state of the M LDOs that are connected, and re-determining Q (is greater than or equal to 2) Integer) An LDO that is in a powered state. Further, the processor sets an output voltage of the voltage converter according to the Q LDO state information (ie, an output voltage of the LDO), that is, sets an output voltage of the voltage converter according to steps 101-103, and replaces N thereof Into Q.

It should be noted that the N is an integer greater than or equal to 2, and the state information is the output voltage. If the output voltages of the plurality of LDOs connected after the voltage converter are the same, the state information is the load current. For example, the output voltage of the voltage converter is set according to the output voltage of the LDO with the largest output voltage in the powered LDO, and the output voltage of the voltage converter is equal to the sum of the output voltage of the LDO and the operating voltage drop thereof; or, according to the above The output voltage of the LDO having the largest load current in the electric LDO sets the output voltage of the voltage converter to determine a threshold voltage corresponding to the load current of the LDO, and the output voltage of the voltage converter is equal to the output voltage of the LDO and the threshold voltage. with.

In the embodiment of the invention, the voltage converter and the LDO can be separately controlled by the processor, and the value of the register of the voltage converter can be adjusted by the processor to adjust the actual output voltage of the voltage converter.

Example 2:

The embodiment of the invention further provides a terminal, which comprises a circuit for adjusting the energy efficiency of the power system, the circuit being connected to the power supply of the terminal. As shown in FIG. 8, the circuit includes: a voltage converter 1, an LDO 2, and a processor 3.

Referring to FIG. 8, the voltage converter 1 includes a first end 11 and a second end 12, and a third end 13, the first end 11 is connected to the power supply of the terminal, and the second end 12 is connected to the processor 3. The three ends 13 are connected to the LDO 2, the third end 13 is an output end of the voltage converter 1 and is connected to the input end of the LDO 2; one end of the processor 13 is connected to the third end 13 of the voltage converter, and the other end Connected to the power supply of the terminal. Processor 3 can be the processor of the terminal.

In a specific implementation, the processor divides the load current interval in advance and determines a threshold voltage corresponding to each load current interval. For example, the load current corresponds to a threshold voltage of 5 mV at [2 mA, 8 mA]. The processor determines that the LDO is in a power-on state by reading status information of each LDO in the register, and determines a current load current of the LDO (ie, Determining a threshold voltage corresponding to the load current (ie, a second threshold voltage), specifically determining a load current interval in which the load current is located, determining that a threshold voltage corresponding to the load current interval is corresponding to the load current Threshold voltage. Finally, the output voltage of the voltage converter is determined based on the threshold voltage and the output voltage of the LDO. Here, the threshold voltage is the voltage at which the LDO operates at the critical point of the linear region and the saturation region.

Further, as shown in FIG. 9, the LDO in the circuit shown in FIG. 8 further includes a power transistor 21, a current sensing circuit 24, a feedback circuit 26, and a first judgment comparison circuit 27. In the embodiment of the present invention, the power tube is taken as an example of the MP tube, wherein the MP tube is a P-type MOS tube.

Specifically, the input end (source) of the power tube 21 is connected to the voltage converter 1, the third end (gate) of the power tube 21 is connected to the current sensing circuit 24, and the output end of the current sensing circuit 24 is connected to the processor 3. The input of current sense circuit 24 is coupled to the output of the voltage converter. An output end (drain) of the power transistor 21 is connected to an input end of the feedback circuit 26, and an output end of the feedback circuit 26 is connected to an input end of the first judgment comparison circuit 27, and an output end of the first judgment comparison circuit 27 and the processor 3 connection.

In a specific implementation, the circuit shown in FIG. 8 or FIG. 9 can be used to implement the method for adjusting the energy efficiency of the terminal power supply provided in this embodiment. As shown in FIG. 10, the method includes the following steps:

201. The processor determines that the LDO is in a power-on state, and determines a current load current of the LDO.

It should be noted that the LDO connected after the voltage converter here is the third target LDO.

In a specific implementation, it is first necessary to determine a state in which the LDO is in an operating state (ie, a power-on state according to an embodiment of the present invention) (eg, a change in load current) to set an output voltage of the voltage converter, After the voltage converter, but the unpowered LDO is not considered. Therefore, firstly, it can be determined that the LDO connected after the voltage converter is in a power-on state.

202. The processor determines a threshold voltage corresponding to the load current.

Wherein the load current is the first load current described in the application; the critical The voltage, which is the second threshold voltage as described herein, is the voltage at which the LDO operates at the critical point of the linear region and the saturation region.

In the specific implementation, in order to ensure the stability of the LDO, the power tube needs to work in the saturation region, that is, the operating voltage drop VDS of the LDO needs to be greater than Vds-sat (ie, the threshold voltage), as shown in FIG. 2, the VDS is the input of the LDO. The difference between voltage and output voltage. As shown in Figure 11, when the LDO is operating in the saturation region, the current difference between the current and its power tube (ie, the operating voltage drop VDS) is not significant, but the load current IDS and the operating voltage drop VDS when the LDO is operating in the linear region. In direct proportion. It is hoped that the LDO will not be affected by VDS when working, so it needs to work in the saturation zone. However, if the VDS is too large, the voltage drop on its power tube will be large. When the load current IDS is large enough, IDS*VDS (where * represents Multiplication, ie power) is used to generate heat. Therefore, it is expected that the LDO operates at the critical point of the linear region and the saturation region, that is, the operating voltage drop VDS=Vds-sat, which can ensure that the LDO operates in the saturation region and also ensures the LDO power. The pressure drop on the tube is minimal.

When the voltage between the gate and the source of the LDO power tube changes, the current-voltage curve of the LDO operates also changes, that is, the voltage between the gate and the source of the LDO power tube is different, and the LDO operates. The current-voltage curves are also different, and the threshold voltages of the saturation region and the linear region are also different in different current-voltage curves. By way of example, Figure 12 shows three different current-

voltage curves

1, 2, 3 when the LDO is operating, and shows the saturation, linear regions corresponding to

curves

1, 2, and 3. As shown in FIG. 12, the

curves

1, 2, and 3 are different, and the threshold voltages corresponding to the

curves

1, 2, and 3 are also different, and the load currents corresponding to the respective threshold voltages are also different. Specifically, the load current of the LDO is different, and the smaller the load current, the smaller the corresponding threshold voltage. For example, as shown in FIG. 11, the load currents I2, I3, (I2 is greater than I3), their corresponding linear regions and saturation boundary voltages (ie, the threshold voltages) are Vds-sat2, Vds-sat3 (Vds, respectively). -sat2 is greater than Vds-sat3).

In order to ensure the performance of the LDO, it is expected that the LDO will operate at the boundary between the linear region and the saturation region at different load currents. Therefore, the output voltage of the voltage converter can be dynamically adjusted according to the load current of the LDO, that is, the corresponding threshold voltage is determined according to the magnitude of the load current as the operating drop (V _dropout ) of the LDO, so that the LDO always operates at the critical voltage.

It should be noted that, in the specific implementation, the configuration parameters of each LDO are all configured in the registers of the terminal, such as the output voltage of each LDO, the operating voltage drop of each LDO, and the threshold voltage corresponding to the load current. Before step 202, the processor first reads the configuration parameters of the third target LDO in the register, and then performs

steps

202 and 203.

203. The processor determines an output voltage of the voltage converter according to the threshold voltage and an output voltage of the LDO.

Specifically, it is determined that an output voltage of the voltage converter is equal to a sum of an output voltage of the LDO and the threshold voltage.

After the processor determines the output voltage of the voltage converter according to the first threshold voltage and the output voltage of the LDO, the current sensing circuit in the circuit shown in FIG. 8 also monitors the load current of the LDO, and then the circuit The processor in the medium can set the output voltage of the voltage converter according to the change of the load current, and specifically includes the following two scenarios:

If the current sensing circuit detects that the load current is greatly reduced, that is, the first load current becomes smaller than the second load current, sending a second interrupt to the processor to indicate a second load current, where the indicating second load current can To indicate the sensing information of the second load current. The current sensing circuit monitors that the load current is reduced from large to large, and can be monitored when the feedback circuit does not detect that the output voltage of the LDO is pulled low.

The processor is configured to determine a load current interval in which the second load current is located, and obtain the second load if a load value interval in which the second load current is located is different from a load value interval corresponding to the second threshold voltage The third threshold voltage corresponding to the load current interval in which the current is located. Because the output voltage of the voltage converter is not continuously adjustable, the current sensing accuracy of the LDO is limited. Therefore, the load current of the LDO can be divided into several sections, and each section corresponds to a threshold voltage, that is, the load currents in the same section all correspond to the same threshold voltage. Interrupts are triggered for each interval to avoid the jumpback caused by the current sensing inaccuracy, which causes the output voltage of the voltage converter to be reset continuously, and an output voltage can be maintained for a certain period of time. Corresponding relationship between the sensing result and the output voltage of the voltage converter is stored in the memory, and the processor determines where the second load current is located The load current interval can directly find the corresponding relationship according to the sensing result of the current sensing circuit, and obtain the output voltage value of the voltage converter, thereby setting the output voltage of the voltage converter. The processor may determine the second load current according to the sensing information of the second load current, thereby determining a load current interval in which the second load current is located

Referring to FIG. 9, when the LDO load current is increased from small to large, the transient response of the load current suddenly increases, which may lower the output voltage of the LDO. However, the processor cannot judge whether the output voltage of the LDO is due to the LDO's input voltage being too low, the VDS is insufficient, and the LDO output voltage is pulled low, or the instantaneous drop due to the transient response of the sudden increase in load current instability. First, the feedback circuit determines whether the output voltage of the LDO is pulled low (ie, whether it is lower than the threshold threshold, the threshold threshold is the output voltage stored in the register for the LDO), and then the first judgment comparison circuit determines the LDO. Whether the output voltage is still below the threshold threshold after a preset duration (eg, a certain debounce time). If so, it can be distinguished from the transient response of the normal LDO. It is considered that the output voltage of the LDO is pulled low because the input voltage of the LDO is too low. Therefore, it is necessary to increase the input voltage of the LDO, that is, the output voltage of the voltage converter.

Next, the first determination comparison circuit sends a first interrupt to the processor, the first interrupt being used to indicate an increase in an output voltage of the voltage converter. The processor then increases the output voltage of the voltage converter until the output voltage of the LDO is no longer below the threshold threshold.

In a specific implementation, the first judgment comparison circuit may send the first interrupt indication processor to increase the output voltage of the voltage converter step by step, and the first interrupt instructs the processor to increase the voltage converter output voltage by the amplitude of each KmV. After the addition, the second determination comparison continues to determine whether the output voltage of the LDO is lower than the output voltage stored in the register for the LDO. If it is lower, the first interrupt is sent to the processor, instructing the processor to increase the output voltage of the voltage converter.

For example, the output voltage of the LDO is pulled down by B, and the output voltage of the voltage converter is increased three times. After three times the output voltage of the voltage converter is increased, the output voltage of the voltage converter is the output voltage of the LDO plus V _dropout,max. (ie LDO's maximum working pressure drop).

The method provided in Embodiment 2 of the present invention is applicable not only to a voltage converter but also to a subsequent one. The LDO scenario is also applicable to a voltage converter followed by multiple LDOs, but only one LDO is powered up.

It should be noted that, using the circuit shown in FIG. 8 or FIG. 9 to adjust the energy efficiency of the power system, the following points need to be noted:

1. The circuit shown in Figure 8 or Figure 9 is suitable for steady-state operating scenarios. If the LDO load current changes over frequency, it will cause frequent adjustments to the output voltage of the voltage converter, which will result in increased power consumption.

2. Since the accuracy of the current sensing circuit inside the LDO is limited, the load current cannot be linearly related to the output of the LDO preamplifier (ie, the output voltage of the voltage converter). Therefore, it is necessary to establish a stepped relationship to load the LDO. The range is divided into N sections, each section corresponding to a threshold voltage, and the output voltage value of the LDO pre-stage is derived from the threshold voltage, and accordingly, there are configurations of N LDO pre-stage outputs.

3, to ensure that the output voltage of the LDO preamplifier (ie, the output voltage of the voltage converter) is configured to respond quickly enough, that is, after the LDO load connected to the voltage converter changes, the second interrupt is received by the processor. It can quickly read the output voltage corresponding to a certain load current value range in the register, and then quickly set the output voltage of the voltage converter. It can prevent the LDO pull-down time from being too long when the LDO load is changed from small to large, and the LDO pull-down time is too long.

4, LDO load current from large to small and from small to large two adjustment mechanisms need to be used together, the processor needs to set the voltage converter output voltage according to the load value range of the load current in response to the second interrupt, and increase in response to the first interrupt Voltage converter output voltage.

The method and terminal for adjusting the energy efficiency of the terminal power supply provided by the embodiment of the present invention, when the power supply of the terminal is connected to the DC-DC voltage converter (ie, the voltage converter), whether the DC-DC voltage converter is connected to multiple LDOs or An LDO can quickly set the output voltage of the DC-DC voltage converter according to the status information (output voltage or load current) of the powered LDO, so that the voltage drop across the LDO remains stable and does not affect the energy efficiency of the entire power system.

Claims

A method for adjusting energy efficiency of a terminal power supply is applied to a terminal, the terminal comprising a power source, a voltage converter connected to the power source, and at least one low dropout linear regulator LDO connected to the voltage converter, wherein , the method includes:

Determining, by the terminal, N LDOs in a power-on state in the at least one LDO; the N being an integer greater than or equal to 1;

The terminal sets an output voltage of the voltage converter according to state information of the N LDOs;

Wherein, the status information includes a load current and/or an output voltage.
The method according to claim 1, wherein if the N is greater than or equal to 2, the terminal setting the output voltage of the voltage converter according to the state information of the N LDOs specifically includes:

Obtaining a maximum operating voltage drop of the first target LDO; the operating voltage drop is a voltage drop when the LDO is in a power-on state; the first target LDO is an LDO having the largest output voltage among the N LDOs;

The output voltage of the voltage converter is set equal to the sum of the maximum operating voltage drop and the output voltage of the first target LDO.
The method according to claim 1, wherein if the N is greater than or equal to 2 and the output voltages of the N LDOs are the same;

The setting, by the terminal, the output voltage of the voltage converter according to the state information of the N LDOs includes:

Obtaining a first threshold voltage corresponding to a load current of the second target LDO; the first threshold voltage is a voltage corresponding to a critical position of the linear region and the saturation region of the second target LDO with the load current, the first The second target LDO is the LDO with the largest load current among the N LDOs;

The output voltage of the voltage converter is set equal to the sum of the output voltage of the second target LDO and the threshold voltage.
The method according to claim 1, wherein if the N is 1, the terminal sets the input of the voltage converter according to the state information of the N LDOs. The voltage output specifically includes:

Determining, by the terminal, a first load current of the LDO;

Obtaining a second threshold voltage corresponding to the first load current; the second threshold voltage is a voltage corresponding to the third target LDO operating at a critical point of the linear region and the saturation region with the first load current;

The output voltage of the voltage converter is set equal to the sum of the output voltage of the third target LDO and the second threshold voltage.
The method according to claim 4, wherein said terminal determines that an output voltage of said voltage converter is equal to a sum of an output voltage of said third target LDO and said second threshold voltage, said method further include:

The terminal detects that the first load current is reduced to a second load current, and determines a load current interval in which the second load current is located;

Obtaining a third threshold voltage corresponding to a load current interval in which the second load current is located, if a load current interval in which the second load current is located is different from a load current interval in which the first load current is located;

The output voltage of the voltage converter is set equal to the sum of the third threshold voltage and the output voltage of the third target LDO.
The method according to claim 4 or 5, wherein after the terminal determines that the output voltage of the voltage converter is equal to the sum of the output voltage of the third target LDO and the second threshold voltage, The method also includes:

The terminal monitors that the output voltage of the third target LDO is lower than the threshold threshold, and determines whether the output voltage of the third target LDO is consistently lower than the threshold threshold for a preset duration;

If it is determined that the output voltage of the third target LDO is consistently lower than the threshold threshold for a preset duration, increasing an output voltage of the voltage converter until an output voltage of the third target LDO is no longer lower than the Threshold threshold.
A terminal, comprising: a processor, a power supply, a voltage converter, and M low-dropout linear regulators LDO, wherein the M is an integer greater than or equal to 1;

The voltage converter is coupled to the power source, the voltage converter and the processor Connected, the voltage converter is connected to the M LDOs;

The processor is configured to determine N LDOs in a power-on state among the M LDOs; the N is an integer greater than or equal to 1;

Setting an output voltage of the voltage converter according to state information of the N LDOs;

The status information is load current and/or output voltage.
The terminal according to claim 7, wherein the LDO specifically includes a power tube, and an input end of the power tube is connected to an output end of the voltage converter;

If the N is greater than or equal to 2, the processor is specifically configured to acquire an output voltage of the N power tubes included in the N LDOs, obtain a maximum operating voltage drop of the first target LDO, and set the voltage converter. The output voltage is equal to a sum of the maximum operating voltage drop and an output voltage of the first target LDO; the first target LDO is an LDO having the largest output voltage among the N power transistors included in the N LDOs, The operating voltage drop is a voltage drop when the first target LDO is in a powered state;

or,

If the output voltages of the N LDOs are the same, acquiring a first threshold voltage corresponding to the load current of the second target LDO, setting an output voltage of the voltage converter equal to an output voltage of the second target LDO and the first a sum of threshold voltages; the first threshold voltage is a voltage corresponding to a power tube of the second target LDO operating at a critical point of a linear region and a saturation region, wherein the second target LDO is the N The LDO with the largest load current among the LDOs.
The terminal according to claim 7, wherein the LDO specifically includes a power tube, and an input end of the power tube is connected to an output end of the voltage converter;

If the N is 1, the processor is specifically configured to: determine a first load current of the third target LDO; acquire a second threshold voltage corresponding to the first load current; the second threshold voltage is The third target LDO operates at a voltage corresponding to a critical portion of the linear region and the saturation region at the first load current; the third target LDO is an LDO that is the only power-on state among the M LDOs;

The processor is further configured to set an output voltage of the voltage converter equal to a sum of an output voltage of the third target LDO and the second threshold voltage.
The terminal according to claim 9, wherein the third target LDO further comprises: a feedback circuit, a first judgment comparison circuit;

The output end of the power tube is connected to the input end of the feedback circuit, and the output end of the feedback circuit is connected to the input end of the first judgment comparison circuit, and the output end of the first judgment comparison circuit is The processor is connected;

The feedback circuit is configured to: if it is determined that an output voltage of the power tube of the third target LDO is lower than the threshold threshold, instructing the first judgment comparison circuit to determine an output voltage of a power tube of the third target LDO Whether it is always below the threshold threshold for a preset period of time;

And if the first judgment comparison circuit determines that the output voltage of the power tube of the third target LDO is consistently lower than the threshold threshold for the preset duration, sending a first interrupt to the processor, where An interrupt for instructing the processor to increase an output voltage of the voltage converter;

The processor is configured to increase an output voltage of the voltage converter until an output voltage of the third target LDO is no longer lower than the threshold threshold.
The terminal according to claim 9 or 10, wherein the third target LDO further comprises a current sensing circuit;

Wherein an input end of the power tube is connected to an output end of the voltage converter, and an output end of the current sensing circuit is connected to the processor;

The current sensing circuit is configured to monitor a change of the first load current; if the current sensing circuit detects that the first load current is changed from large to small, send a second interrupt to the processor; The second interrupt is used to indicate the second load current;

The processor is configured to determine a load current interval in which the second load current is located, and if the load current interval in which the second load current is located is different from a load current interval in which the first load current is located, acquiring the a third threshold voltage corresponding to a load current interval in which the load current is located;

The processor is further configured to set an output voltage of the voltage converter equal to a sum of an output voltage of the power tube of the third target LDO and the third threshold voltage.