WO2019129280A1

WO2019129280A1 - Load switch circuit, battery assembly, and multi-power system

Info

Publication number: WO2019129280A1
Application number: PCT/CN2018/125654
Authority: WO
Inventors: Han Wu; Jinxiang Shen
Original assignee: Sengled Co., Ltd.
Priority date: 2017-12-29
Filing date: 2018-12-29
Publication date: 2019-07-04
Also published as: CN107968641B; CN107968641A

Abstract

A load switch circuit, a battery assembly, and a multi-power system. The load switch circuit includes a switch unit and a first resistor, where an input of the switch unit is connected to an anode of a battery, an output of the switch unit is connected to an input of a load, an enable of the switch unit is connected a first terminal of the first resistor, and a second terminal of the first resistor is connected to the ground. The enable of the switch unit controls the switch unit to be turned on to supply power to the load; and the enable of the switch unit also controls the switch unit to be turned off to prevent the load from reversely charging the battery. The load switch circuit of the present disclosure provides the technical solution to address the voltage drop over the diode on the power rail of the conventional load switch circuit. Since the on-resistance of the switch is low, the voltage drop is much lower than the voltage drop over the diode, so the power supply voltage provided by the battery to the load may be improved.

Description

[Title established by the ISA under Rule 37.2] LOAD SWITCH CIRCUIT, BATTERY ASSEMBLY, AND MULTI-POWER SYSTEM

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the priority to Chinese Patent Application No. 201711480252.9 entitled "A Load Switch Circuit, A Battery Assembly, and A Multi-Power System” filed on December 29, 2017, the entire content of which is incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to the field of circuit technology. More specifically, the present disclosure relates to a load switch circuit, a battery assembly, and a multi-power system.

BACKGROUND

A wide variety of batteries are currently being used as a power source that is typically connected to a load switch circuit. The load switch circuit provides numerous of advantages to the batteries as the load switch circuit is capable of turning the power rail on or off to reduce power consumption and avoid the batteries from being affected by the reverse current from the load.

FIG. 1 is a schematic circuit diagram of a conventional load switch circuit. Referring to FIG. 1, the conventional load switch circuit typically places a diode on the power rail to prevent reverse charging and reduce the manufacturing cost. However, for batteries with lower minimal operating voltage (such as button cell batteries, where a typical lithium manganese button cell battery will have a power range of 2-3V) , the forward voltage of the diode may be divided, which may reduce the voltage that the batteries provide to the load, and stop the load from working properly in severe cases.

SUMMARY

Embodiments of the present disclosure provide a load switch circuit, a battery assembly, and a multi-power system to improving the conventional load switch circuit that reduces the voltage from the battery to the load due to the forward voltage of the diode.

One aspect of the present disclosure provides a load switch circuit. The load switch circuit includes a switch unit and a first resistor, where an input of the switch unit is connected to an anode of a battery, an output of the switch unit is connected to an input of a load, an enable of the switch unit is connected to a first terminal of the first resistor, and a second terminal of the first resistor is connected to the ground. The enable of the switch unit is configured to control the switch unit to be turned on to allow the battery to supply power to the load; and control the switch unit to be turned off to prevent the load from reversely charging the battery.

In one embodiment, the load switch circuit may further include a first switching element and a first diode, where an input of the first switching element may be connected to the anode of the battery, an output of the first switching element may be connected to the input of the load, an enable of the first switching element may be connected to a first terminal of the first resistor and an anode of the first diode, a cathode of the first diode may be connected to the input of the load, and the enable of the first switching element may be the enable of the switch unit. Further, the enable of the first switching element may be configured to control the first switching element to be turned on to allow the battery to supply power to the load. Furthermore, the enable of the first switching element may also be configured to control the first switching element to be turned off to prevent the load from reversely charging the battery; and the enable of the first switching element may also be configured to control the first diode to be turned on and off.

In one embodiment, the first switching element may be a PMOS transistor.

In one embodiment, the load switch circuit may further include a second diode, where an anode of the second diode may be connected to a second terminal of the first resistor, a cathode of the second diode may be connected to the output of the switch unit, and the cathode of the second diode may connected to the input of the load.

In one embodiment, the switch unit may further include a second switching element and a second resistor, where an input of the second switching element may be connected to the anode of the battery, an output of the second switching element may be connected to the input of the load, an enable of the second switching element may be connected to a first terminal of the second resistor, a second terminal of the second resistor may be connected to the first terminal of the first resistor, and the second terminal of the second resistor may be the enable of the switch unit. Further, the enable of the switch unit may control the second switching element to be turned on to allow the battery to supply power to the load; and the enable of the switch unit may control the second switching element to be turned off to prevent the load from reversely charging the battery.

In some embodiments, the second switching element may be a PNP type triode.

In some embodiments, the switch unit may further include a third switching element, a fourth switching element, a third resistor, a fourth resistor, and a fifth resistor, where an enable of the third switching element may be respectively connected to a first terminal of the third resistor and a first terminal of the fourth resistor, an input of the third switching element may be respectively connected to an enable of the fourth switching element and a first terminal of the fifth resistor, an output of the third switching element, an output of the fourth switching element, and a second terminal of the fourth resistor may be respectively connected to the cathode of the battery, a second terminal of the fifth resistor may be respectively connected to the anode of the battery and the input of the load, an input of the fourth switching element may be connected to the ground, and a second terminal of the third resistor may be connected to the first terminal of the first resistor and the may be the enable of the switch unit. Further, the enable of the switch unit may control the third switching element to be turned off and the fourth switching element to be turned on to allow the battery to supply power to the load; and the enable of the switch unit may control the third switching element to be turned on and the fourth switching element to be turned off to prevent the load from reversely charging the battery.

In some embodiment, the third switching element may be an NPN type triode, and the fourth switching element may also be an NPN type triode.

Another aspect of the present disclosure provides a battery assembly. The battery assembly includes a battery and a load switch circuit mentioned above. For example, the load switch circuit includes a switch unit and a first resistor, where an input of the switch unit is connected to an anode of a battery, an output of the switch unit is connected to an input of a load, an enable of the switch unit is connected to a first terminal of the first resistor, and a second terminal of the first resistor is connected to the ground. The enable of the switch unit is configured to control the switch unit to be turned on to allow the battery to supply power to the load; and control the switch unit to be turned off to prevent the load from reversely charging the battery.

Another aspect of the present disclosure provides a multi-power system. The multi-power system includes a plurality of battery assemblies mentioned above, an analog-to-digital converter, and a controller, where the anodes of the batteries in each battery assembly may be respectively connected to an input of the analog-to-digital converter, and an output of the analog-to-digital converter may be connected to an input of the controller. Further, the controller may be configured to compare power supply voltages of the one or more battery assemblies, select a battery assembly based on the power supply voltages, , and output an enabling signal to the enable of the selected battery assembly to allow the selected battery assembly to supply power for the load.

The embodiments of the present disclosure provide a load switch circuit, a battery assembly, and a multi-power system. The anode of the battery may be connected to the input of the switch unit, and the output of the switch unit may be connected to the input of the load. Further, the enable of the switch unit may be connected to the first terminal of the first resistor, and the second terminal of the first resistor may be connected to the ground. Furthermore, the enable of the switch unit may control the switch unit to be turned on to enable the battery to supply power to the load. In addition, the enable of the switch unit may also control the switch unit to be turned off to prevent the load from reversely charging the battery. The present disclosure improves the voltage drop on the power rail from the diode in the conventional load switch circuit. Since the on-resistance of the switch unit is low, the voltage drop may be much lower than the diode, thereby increasing the voltage the battery supplies to the load and preventing the load from reversely charging the battery, which may protect the battery and extend the battery life.

BRIEF DESCRIPTION OF DRAWINGS

For a more complete understanding of the present disclosure, and the advantages thereof, reference is now made to the following descriptions to be taken in conjunction with the accompanying drawings. The accompanying drawings in the following description show merely some embodiments of the present invention, and a person of ordinary skill in the art may still derive other drawings from these accompanying drawings without creative efforts.

FIG. 1 is a schematic circuit diagram of a conventional load switch circuit provided in the present disclosure;

FIG. 2 is a schematic of the load switch circuit according to an embodiment of the present disclosure;

FIG. 3 is a first schematic circuit diagram of the load switch circuit according to an embodiment of the present disclosure;

FIG. 4 is a second schematic circuit diagram of the load switch circuit according to an embodiment of the present disclosure;

FIG. 5 is a third schematic circuit diagram of the load switch circuit according to an embodiment of the present disclosure;

FIG. 6 is a fourth schematic circuit diagram of the load switch circuit according to an embodiment of the present disclosure;

FIG. 7 is a schematic structural view of a battery assembly according to an embodiment of the present disclosure;

FIG. 8 is a schematic structural view of a multi-power system according to an embodiment of the present disclosure;

FIG. 9-1 is a schematic circuit diagram of a multi-power system according to an embodiment of the present disclosure; and

FIG. 9-2 is a schematic circuit diagram of another multi-power system according to an embodiment of the present disclosure.

DESCRIPTION OF EMBODIMENTS

Hereinafter, aspects, features, and embodiments of the present disclosure will be described with reference to the accompanying drawings. It should be understood that such description is exemplary only but is not intended to limit the scope of the present disclosure. In addition, it will be understood by those skilled in the art that various modifications in form and details may be made therein without departing from the spirit and scope of the present disclosure.

Features and aspects of the present disclosure will become apparent with reference to the accompanying drawings and non-limiting examples describing various preferred embodiments of the present disclosure.

It will also be appreciated that although the present disclosure has been described with reference to some specific examples, equivalents of the present disclosure can be achieved by those skilled in the art. These equivalents having features claimed in the present disclosure should fall within the scope of protection defined hereinafter.

Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. It should be understood that such description is exemplary only but is not intended to limit the scope of the present disclosure. In addition, in the following description, descriptions of well-known structures and techniques are omitted to avoid unnecessarily obscuring the concepts of the present disclosure. Therefore, specific structural and functional details disclosed herein are not intended to be limiting, but are merely used as a basis of the claims to teach those skilled in the art to use the present disclosure in various combinations.

The terms used herein is for the purpose of describing particular embodiments only but is not intended to limit the present disclosure. The words “a” , “an” and “the” as used herein should also cover the meanings of “a plurality of” and “a variety of” , unless the context clearly dictates otherwise. In addition, the terms “comprising” , “including” , “containing” and the like as used herein indicate the presence of the features, steps, operations and/or components, but do not preclude the presence or addition of one or more other features, steps, operations or components.

The phrases “in an embodiment” , “in another embodiment” , “in another embodiment” , or “in other embodiments” may refer to the same or different embodiments accordingly to the present disclosure.

When a conventional load switch circuit is used to build a conventional discrete device, the battery may not be able to provide the required voltage to the load due to the voltage division over the diode, so the load may not be able to work properly. Alternatively, the conventional load switch circuit may also be implemented through chip integration, in this case, the circuit structures for current limiting, logic control, and gate driving need to be integrated into the chip. However, since the chip needs to maintain functions such as logic control, the static power consumption of the chip is high, and the manufacturing cost of the chip is also high. To overcome the abovementioned challenges, in conjunction with FIG. 2, the present embodiment prevents the battery from being affected by the reverse current by adjusting the switch unit, so the load can work normally.

FIG. 2 is a schematic of the load switch circuit according to an embodiment of the present disclosure. Referring to FIG. 2, the load switch circuit of the present embodiment may include a switch unit and a first resistor, where an anode of the battery may be connected to an input (i.e., an input terminal) of the switch unit, an output (i.e., an output terminal) of the switch unit may be connected to the input of the load, an enable (i.e., an enable terminal) of the switch unit may be connected to a first terminal of the first resistor, and a second terminal of the first resistor may be connected to the ground.

Further, the enable of the switch unit may control the switch unit to be turned on to allow the battery to supply power to the load. Furthermore, the enable of the switch unit may also control the switch unit to be turned off to prevent the load from reversely charging the battery.

More specifically, in the present embodiment, the enable of the switch unit may control the on or off of the switch unit, and the specific implementation of the switch unit is not limited in the present embodiment.

In some embodiments, when the enable of the switch unit is grounded or floating, the switch unit may be turned on. Further, the input of the switch unit is used to connect the anode of the battery, and the output of the switch unit is used to connect the input of the load. When the anode of the battery is connected to the input of the switch unit and the output of the switch unit is connected to the load, the battery is connected to supply power to the load, so the load may perform its normal operation.

When the enable of the switch unit is connected to a high voltage (e.g., the enable may be set to high voltage when an external power is available) , the switch unit may be turned off. Further, the input of the switch unit is used to connect the anode of the battery, and the output of the switch unit is used to connect the input of the load. When the anode of the battery is connected to the input of the switch unit and the output of the switch unit is connected to the load, since the battery is turned off, the reverse current from the load will not be able to flow to the battery, thus preventing the load from reversely charging the battery, thereby protecting the battery and extending the battery life.

Further, the first terminal of the first resistor may be connected to the enable of the switch unit, and the second terminal of the first resistor may be connected to the ground. Therefore, when the enable of the switching is not connected to any signal (e.g., when the external power is not available) , the first resistor may make the enable of the switch unit at a low voltage, so the switch unit may be turned on. In the present embodiment, since the on-resistance of the switch unit is low, the voltage drop corresponding to the switch unit is very low, and is much lower than the voltage drop of a diode in the conventional technology, so the battery power will not be wasted. In some embodiments, Vcc is a line indicating a power signal directly connected to the load.

The embodiment of the present disclosure provides a load switch circuit. In particular, the anode of the battery may be connected to the input of the switch unit, and the output of the switch unit may be connected to the input of the load. The enable of the switch unit may be connected to the first terminal of the first resistor, and the second terminal of the first resistor may be connected to the ground. In addition, the enable of the switch unit may control the switch unit to be turned on to enable the battery to supply power to the load. Further, the enable of the switch unit may also control the switch unit to be turned off to prevent the load from reversely charging the battery. The present disclosure improves the voltage drop on the power rail (e.g., the path from the battery to the load) over the diode in the conventional load switch circuit. Since the on-resistance of the switch unit is low, the voltage drop is much lower than the diode, thereby increasing the voltage the battery supplies to the load and preventing the load from reversely charging the battery, which may protect the battery and extend the battery life.

The switch unit of the present embodiment may be implemented in various manners. Further to the foregoing embodiment of FIG. 2, and in conjunction with FIG. 3, FIG. 4, and FIG. 5, three specific embodiments of the implementation of the switch unit will be described in detail.

Further to the embodiment of FIG. 2, FIG. 3 is a first schematic circuit diagram of the load switch circuit according to an embodiment of the present disclosure. Referring to FIG. 3, the switch unit of the present embodiment may further include a first switching element and a first diode.

An input of the first switching element may be connected to the anode of the battery, an output of the first switching element may be connected to the input of the load, an enable of the first switching element may be respectively connected to the first terminal of the first resistor and an anode of the first diode, and a cathode of the first diode may be connected to the input of the load, the second terminal of the first resistor may be connected to the ground, and the enable of the first switching unit may be the enable of the switch unit.

In some embodiments, the enable of the first switching element may control the first switching element to be turned on, so the battery may supply power to the load. Further, the enable of the first switching element may control the first switching element to be turned off to prevent the load from reversely charging the battery. Furthermore, the enable of the first switching element may be used to control the on or off of the first diode.

More specifically, the enable of the first switching element in the present embodiment may control the first switching element to be turned on or off, and the specific control method of the first switching element is not limited in this embodiment. In some embodiments, when the enable of the first switching element is grounded or floating, the first switching element may be turned on. Further, when the enable of the first switching element is connected to a high voltage, the first switching element may be turned off.

When the battery is connected to the input of the first switching element, and the output of the first switching element is connected to the load, the enable of the first switching element may control the first switching element to be turned on. In this case, the voltage drop on the power rail from the battery to the load may be much lower than the voltage drop across one conventional diode, the power consumption of the battery may be lower, so the battery may properly supply power to the load.

When the battery is connected to the input of the first switching element, and the output of the first switching element is connected to the load, the enable of the first switching element may control the first switching element to be turned off. In this case, the load will not be able to reversely charge the battery, thereby protecting the battery and extend the battery life.

Further, the first switching element in the present embodiment may include different types of switching elements that are not limited in this embodiment. In some embodiments, the first switching element may be a P-channel Metal Oxide Semiconductor (PMOS) transistor. For the convenience of explanation, the first switching element in FIG. 3 of the present disclosure is illustrated by a PMOS transistor.

More specifically, when the first switching element is a PMOS, since the PMOS itself includes a parasitic diode, the source and drain of the PMOS are reversed in the present embodiment. Thus, the enable of the first switching element may be a gate of the PMOS, the input of the first switching element may be a drain of the PMOS, which may be connected to the anode of the battery, and the output of the first switching element may be a source of the PMOS, which may be used to connect to the input of the load. In this case, the PMOS, which is reversed from the source and drain may be connected in parallel with the two terminals of a diode to form a current path.

When the gate of the PMOS is connected to the ground or floating, the gate voltage of the PMOS may be 0, and the drain voltage of the PMOS may be almost equal to the power supply voltage of the battery (i.e., the PMOS is off and the switch unit is off) . When the PMOS is turned on (e.g., when the enable, i.e., the gate voltage of the PMOS, is set to high) , the parasitic diode may be shorted, the source voltage of the PMOS may be almost equal to the drain voltage of the PMOS, the voltage drop between the drain and the source of the PMOS may be lower than the forward voltage across a conventional diode (i.e., without the circuit structure that comprises the PMOS and the diode connected to the drain and source of the PMOS in parallel) , so the loss on the battery power will not be excessive and can supply power to the load normally.

Further, at the instant when the PMOS is turned on, since drain and source are of the PMOS are asymmetric, the gate-source threshold voltage (Vsd (on) ) of the PMOS may change. In this case, the source and drain voltages of the POMS are both higher than the gate voltage of the POMS, which is better for the formation of the inversion layer-P channel. At the same time, the power supply voltage of the battery is generally higher than (Vsd (on) ) , so after the charging between the gate and source of the PMOS is completed, the PMOS may enter the diode region. At this time, the equivalent DC resistance between the source and the drain of PMOS is lower (for example, 100mΩ) . If the current mainly flows through the PMOS channel, then the voltage drop on the power rail may be lower (for example, a 100mΩDC impedance of supplying current at 1A only creates a voltage drop of 0.1V) .

When the gate voltage of the PMOS is higher than the power supply voltage of the battery, the drain voltage of the PMOS may be almost equal to the power supply voltage of the battery. When the PMOS is turned off, the anode of the parasitic diode is connected to the anode of the battery, the cathode of the parasitic diode is connected to the input of the load to prevent the load from reversely charging the battery.

Further, the source and drain of the PMOS are reversely connected to the battery and the load respectively in the present embodiment to prevent reverse current from flowing to the battery. In addition, the quiescent current of the load switch circuit is low, so the voltage drop on the power rail over the diode may be addressed to support a larger current. This is especially suitable for the power management of the low voltage battery.

More specifically, the enable of the first switching element in the present embodiment may also connected to the anode of the first diode, and the cathode of the first diode may be connected to the input of the load. Since the enable of the first switching element may be connected to different voltages, when the first switching element is grounded or floating, the first diode cannot be turned on, and the first switching element can be turned on, so that the battery can charge the load. In addition, when the first switching element is connected to a second power source (e.g., a second battery or a rectified source from a power grid) , and the power supply voltage of the second power source is higher than the power voltage of the first battery, the first switching element may be turned off, but the second power source may charge the load via the enable of the first switching element and the first diode (i.e., the first diode is turned on) , so the load switch circuit can use different power sources to satisfy various load demands. In some embodiments, the first diode may be replaced with another circuit component, such as the disclosed switch unit to reduce voltage drop on the circuit component when the second battery is supplying power to the load.

Further to the embodiment of FIG. 2, FIG. 4 is a second schematic circuit diagram of the load switch circuit according to an embodiment of the present disclosure. Referring to FIG. 4, the load switch circuit of the present embodiment may further include a second diode, where an anode of the diode may be connected to the second terminal of the first resistor, and a cathode of the second diode may be connected to the output of the switch unit and the cathode of the second diode may be used to connect the input of the load.

More specifically, when the enable of the switch unit is connected to a high voltage, the switch unit may be turned off. Therefore, in this embodiment, the second diode may be connected in parallel between the output of the switch unit and the ground, and the second diode may release the voltage from the enable of the switch unit, so when the switch unit is turned off, the second diode may prevent sudden drop of the current on the load and allow the current to slowly drop to 0 and stop working.

FIG. 5 is a third schematic circuit diagram of the load switch circuit according to an embodiment of the present disclosure. Referring to FIG. 5, the switch unit may further include a second switching element and a second resistor.

In particular, an input of the second switching element may be connected to the anode of the battery, an output of the second switching element may be connected the input of the load, an enable of the second switching element may be connected to a first terminal of the second resistor, a second terminal of the second resistor may be connected to the first terminal of the first resistor, and the second terminal of the second resistor may be the enable of the switch unit.

The enable of the switch unit may be used to control the second switching element to be turned on, so the battery may supply power to the load. Further, the enable of the switch unit may be used to control the second switching element to be turned off to prevent the load from reversely charging the battery.

More specifically, since the second resistor and the enable of the second switching element are connected, after the voltage coming from the enable of the switch unit flows through the second resistor, a suitable current may be generated to flow to the enable of the second switching element, so the second switching element may be turned on or off.

Further, in the present embodiment, the enable of the switch unit may control the current of the enable of the second switching element, so the enable of the second switching element may control the second switching element to be turned on or off. In particular, the specific control method of the second switching element is not limited in the present embodiment. Furthermore, when the enable of the switch unit is grounded or floating, the enable of the second switching element may control the second switching element to be turned on; when the enable of the switch unit is connected to a high voltage, the enable of the second switching element may control the second switching element to be turned off.

In addition, when the input of the second switching element is connected to the battery, and the output of the second switching is connected to the load, the voltage of the enable of the switch unit may control the enable of the second switching element to turn on the second switching element. Since the on-resistance of the second switching element is low, the voltage drop on the power rail from the battery to the load may be lower than the voltage drop across a conventional diode, so the power consumption on the battery will be low, allowing the battery to properly supply power to the load.

Further, when the input of the second switching element is connected to the battery, and the output of the second switching is connected to the load, the voltage of the enable of the switch unit may control the enable of the second switching element to turn off the second switching element. At this point, the reverse current from the load cannot flow to the battery, so the load cannot reversely charge the battery, thereby protecting the battery and extending the battery life.

Furthermore, the second switching element in this embodiment may include different types of switching elements that are not limited in the present embodiment. In some embodiments, the second switching element may be a PNP type triode. For the convenience of explanation, the second switching element in FIG. 5 of the present embodiment is illustrated as a PNP type triode.

More specifically, the enable of the second switching element in the present embodiment may be a base of the PNP type triode, the input of the second switching element may be an emitter of the PNP type triode that may be connected to the anode of the battery, and the output of the second switching element may be a collector of the PNP type triode that may be connected to the input of the load.

When the enable of the switch unit is grounded or floating, the base voltage of the PNP type triode may be 0, the emitter voltage of the PNP type triode may be almost equal to the power supply voltage of the battery, the PNP type triode may be turned on, and the collector voltage of the PNP type triode may be almost equal to the emitter voltage of the PNP type triode. The voltage drop between the emitter and the collector of the PNP triode may be lower than the forward voltage of a conventional diode. Therefore, the loss on the battery power will not be excessive and can supply power to the load normally.

When the enable of the switch unit is connected to the power supply voltage higher than the battery (such as when connected to the anode of other power supplies) , the emitter voltage of the PNP triode may be almost equal to the power supply voltage of the battery, that is, the base voltage of the PNP type triode may be higher than the emitter voltage of the PNP type triode, and the PNP type triode may be turned off, the battery may stop supplying power to the load, and the load may not be able to reversely charge the battery.

FIG. 6 is a fourth schematic circuit diagram of the load switch circuit according to an embodiment of the present disclosure. Referring to FIG. 6, the load switch circuit of the present embodiment may further include: a third switching element, a fourth switching element, a third resistor, a fourth resistor, and a fifth resistor.

In particular, an enable of the third switching element may be respectively connected to a first terminal of the third resistor and a first terminal of the fourth resistor; an input of the third switching element may be respectively connected to an enable of the fourth switching element and a first terminal of the fifth resistor; an output of the third switching element, an output of the fourth switching element, and a second terminal of the fourth resistor may be respectively connected to the cathode of the battery; a second terminal of the fifth resistor may be respectively connected to the anode of the battery and the input of the load; an input of the fourth switching element may be connected to the ground; a second terminal of the third resistor may be connected to the first terminal of the first resistor; and the second terminal of the third resistor may be the enable of the switch unit.

The enable of the switch unit may be used to control the third switching element to be turned off, and the fourth switching element may be turned on, so the battery may supply power to the load. In addition, the enable of the switch unit may also be used to control the third switching element to be turned on, and the fourth switching element may be turned off to prevent the load from reversely charging to the battery.

More specifically, since the third resistor is connected to the enable of the third switching element, after the voltage from the enable of the switch unit passes through the third resistor, a suitable current may be generated to flow to the enable of the third switching element, so the third switching element may be turned on or off. In addition, since the input of the third switching element is connected to the enable of the fourth switching element, by turning the third switching element on or off, the current flow at the input of the third switching element may be changed, so the fourth switching element may be turned on or off.

Further, in the present embodiment, the enable of the switch unit can control the current at the enable of the third switching element, so the enable of the third switching element may control the third switching element to be turned on or off. The specific control method of the third switching element is not limited in the present embodiment. Furthermore, turning the third switching element on or off may control the current at the input of the third switching element, which may turn the fourth switching element on or off. In some embodiments, when the enable of the switch unit is grounded or floating, the enable of the third switching element may control the third switching element to be turned off, and the enable of the fourth switching element may control the fourth switching element to be turned on.When the enable of the switch unit is connected to a high voltage, the enable of the third switching element may control the third switching element to be turned on, and the enable of the fourth switching element may control the fourth switching element to be turned off.

In some embodiments, since the output of the fourth switching element may be connected to the cathode of the battery, the anode of the battery may be connected to the input of the load, and the input of the fourth switching element may be connected to the ground, a circuit may be formed by the fourth switching element, the battery and the load.

In some embodiments, when the second terminal of the fifth resistor is connected to the anode of the battery and the input of the load, and the cathode of the battery is connected, the voltage from the enable of the switch unit will pass through the third resistor, so the current flowing into the enable of the third switching element may control the third switching element to be turned off. Further, the input of the third switching element may be connected to the enable of the fourth switching element to control the fourth switching element to be turned on, so the circuit formed by the fourth switching element, the battery and the load may be turned on. Furthermore, the on-resistance of the fourth switching element is low, so the battery has no voltage drop or minimal voltage drop on the power rail of the load, that may be lower than the forward voltage of a diode, therefore, the loss on the battery power will not be excessive and can supply power to the load normally.

In some embodiments, when the second terminal of the fifth resistor is connected to the anode of the power source and the input of the load, and the cathode of the power source is connected, the voltage from the enable of the switch unit will pass through the third resistor, so the current flowing into the enable of the third switching element may control the third switching element to be turned on. Further, the input of the third switching element may be connected to the enable of the fourth switching element to control the fourth switching element to be turned off, so the circuit formed by the fourth switching element, the battery and the load may be turned off. At this time, the reverse current from the load cannot flow to the battery, hence, the load cannot reversely charge the battery, thereby protecting the battery and extend the battery life.

In addition, the third switching element and the fourth switching element in the present embodiment may include different types of switching elements that are not limited in the present embodiment. In some embodiments, the third switching element and the fourth switching element may both be an NPN type triode. For the convenience of explanation, the third switching element and the fourth switching element in the present embodiment in FIG. 6 are both illustrated by an NPN type triode.

More specifically, the end of the third switching element in the present embodiment may be a base of a first NPN type triode, the input of the third switching element may be a collector of the first NPN type triode, which may be connected to the bases of the fifth resistor and the fourth switching element. Further, the fifth resistor may be connected to the anode of the battery, the output of the third switching element may be an emitter of the NPN type triode, which may be connected to the cathode of the battery. Furthermore, the enable of the fourth switching element may be a base of a second NPN triode, and the input of the fourth switching element may be a collector of the second NPN triode, which may be connected to the ground. The output of the fourth switching element may be an emitter of the second NPN type triode, which may be connected to the cathode of the battery, and the anode of the battery may be connected to the input of the load.

In some embodiments, when the enable of the switch unit is grounded or floating, the base voltage of the first NPN triode may be 0, the emitter voltage of the first NPN triode may be 0, and the first NPN triode may be turned off. The base voltage of the second NPN triode may equal to the voltage division of the battery through the fifth resistor, the emitter voltage of the second NPN triode may be zero, and the second NPN triode may be turned on. Thus, a circuit may be formed by the second NPN type triode, the battery, and the load. Moreover, the voltage drop between the emitter and the collector of the second NPN triode may be lower than the forward voltage of a diode, so the battery does not have excessive loss and can supply power to the load normally.

When the enable of the switch unit is connected to the power supply voltage higher than the battery (such as when connected to the anode of other power supplies) , the base voltage of the first NPN type triode may equal to the voltage division of the voltage through the third resistor, the emitter voltage of the first NPN triode may be 0, the first NPN transistor may be turned on, the collector of the NPN type triode may output a low voltage, the base of the second NPN type triode may output a low voltage, the emitter voltage of the second NPN type triode may be 0, and the second NPN type transistor is turned off. Thus, the circuit may be formed by the second NPN triode, the battery, and the load may be turned off, the battery may stop supplying power to the load, and the load may not be able to reversely charge the battery.

FIG. 7 is a schematic structural view of a battery assembly according to an embodiment of the present disclosure. Referring to FIG. 7, the battery assembly of the present embodiment includes a battery 11 and the aforementioned load switch circuit 12.

The battery assembly of the present embodiment includes a load switch circuit 12, which may be used to perform the technical solutions of the embodiments of the load switch circuit 12 of the present disclosure. The implementation principle and technical effects are similar, and are not described herein again.

FIG. 8 is a schematic structural view of a multi-power system according to an embodiment of the present disclosure. Referring to FIG. 8, the multi-power system of the present embodiment includes a plurality of the aforementioned battery assemblies 10, an analog-to-digital converter 20, and a controller 30.

In particular, the anodes of the batteries in each of the battery assemblies 10 may be respectively connected to the inputs of the analog-to-digital converter 20, the output of the analog-to-digital converter 20 may be connected to the input of the controller 30, and the output of the controller 30 may be connected to the switch enable of the load (e.g., enable of each battery assembly) . The output of the switch unit of each of the battery assemblies 10 may be respectively connected to the same load. Further, the controller 30 may compare the power supply voltages of the respective battery assemblies 10 to select a power supply voltage of the load.

More specifically, the analog-to-digital converter 20 may be connected to the batteries in each of the battery assemblies 10, the controller 30 may be connected to the analog-to-digital converter 20 to acquire the power supply voltage of each battery. Based on the power supply voltage required for the load, the controller 30 may compare the power supply voltages of the respective battery assemblies 10 to select the power supply voltage required by the load. Subsequently, the controller may send the corresponding instructions to the enable of the load, so the battery assembly that satisfies the load demand may supply power to the load. For example, the controller may output an enabling signal (e.g., an enabling voltage) to the enable of the selected battery assembly so that the switch unit of the selected battery assembly is turned on and the battery of the selected battery assembly can supply power to the load, and/or output disabling voltage to the enable (s) of all the unselected battery assemblies so that the switch units of all the unselected battery assemblies are turned off. In addition, the connection between one of the battery assemblies 10 and the load may be implemented through the use of a digital decoder and a multiplexer chip to determine the power supply voltage capable of supplying power to the load from each of the battery assembly 10, thereby saving the resources on the controller 30, and enable automatic switching of the battery channels in each battery assembly.

The multi-power supply system of the present embodiment includes a plurality of battery assemblies 10, and any of the battery assemblies 10 may include a load switch circuit, which may be used to implement the technical solutions of the embodiments of the load switch circuit of the present invention, and the implementation principle and technical effects thereof. Similar, it will not be described here.

FIG. 9-1 is a schematic circuit diagram of a multi-power system according to an embodiment of the present disclosure. As shown in FIG. 9-1, the multi-power system includes multiple battery assemblies and a controller embedded with multiple analog-to-digital converter (ADC) input ports. That is, the controller is capable of converting an analog signal inputted at its ADC input port to a digital signal. The anodes of the two batteries are respectively connected to an ADC input of the controller. The enables of the two load switch circuits are respectively connected to an output port of the controller. Both battery assemblies are connected to the same load. The controller may compare the power supply voltages of the respective battery assemblies to select a desired battery assembly for the load, and send an output signal to the enable of the selected battery assembly.

FIG. 9-2 is a schematic circuit diagram of another multi-power system according to an embodiment of the present disclosure. As shown in FIG. 9-2, the multi-power system includes multiple battery assemblies, a controller embedded with one ADC input port, and a multiplexer. Each anode of the batteries may be connected to the multiplexer. One of the anodes may be connected to the ADC input of the controller based on a selection from the multiplexer. That is, when one anode is connected to the ADC input of the controller through the multiplexer, other anodes connected to the multiplexer is disconnected. The selection from the multiplexer may be controlled by the controller through control signal connection (s) . The multiplexer may include a decoder to process the control signal from the controller and respond accordingly. By using the multiplexer to individually connect one of the anodes to the ADC input of the controller, the controller may obtain the power supply voltages of the respective battery assemblies. Further, the controller may send an output signal to the enable of the selected battery assembly to power the load.

It can be understood that although FIGS. 9-1 and 9-2 show two battery assemblies. Similar connections and functions can be implemented in multi-power systems with more than two battery assemblies.

Those skilled in the art may clearly understand that, for ease and concision of the descriptions, the aforementioned processing method may be applied to the related electronic devices, and the related details may refer to corresponding descriptions in the disclosed embodiments, which are not repeated herein.

The embodiments in this specification are described in a progressive manner, each embodiment emphasizes a difference from the other embodiments, and the identical or similar parts between the embodiments may be made reference to each other. Since the apparatuses disclosed in the embodiments are corresponding to the methods disclosed in the embodiments, the description of the apparatuses is simple and relevant parts may be made reference to the description of the methods.

Persons skilled in the art may further realize that, units and steps of algorithms according to the description of the embodiments disclosed by the present disclosure can be implemented by electronic hardware, computer software, or a combination of the two. In order to describe interchangeability of hardware and software clearly, compositions and steps of the embodiments are generally described according to functions in the forgoing description. Whether these functions are executed by hardware or software depends upon specific applications and design constraints of the technical solutions. Persons skilled in the art may use different methods for each specific application to implement the described functions, and such implementation should not be construed as a departure from the scope of the present disclosure.

The steps of the methods or algorithms described in the embodiments of the present disclosure may be directly implemented by hardware, software modules executed by the processor, or a combination of both. The software module can be placed in a random access memory (RAM) , memory, read only memory (ROM) , electrically programmable ROM, electrically erasable and programmable ROM, register, hard disk, mobile disk, CD-ROM, or any other form of storage medium known to the technical domain.

It will be understood by those skilled in the art that the features described in the respective embodiments and/or claims of the present disclosure can be combined in various ways, even if such combinations are not explicitly described in the present disclosure. In particular, without departing from the spirit and teaching of the present disclosure, the features described in the respective embodiments and/or claims can be combined in various ways. All of these combinations fall within the scope of the present disclosure.

While the present disclosure has been shown and described with reference to various embodiments thereof, it will be understood by those skilled in the art that various modifications in form and details may be made therein without departing from the spirit and scope of the present disclosure as defined by the appended claims and their equivalents. Therefore, the scope of the present disclosure should not be limited to the above-described embodiments but should be determined by not only the appended claims but also the equivalents thereof.

It should be noted that the description of the foregoing embodiments of the electronic device may be similar to that of the foregoing method embodiments, and the device embodiments have the same beneficial effects as those of the method embodiments. Therefore, details may not be described herein again. For technical details not disclosed in the embodiments of the electronic device of the present disclosure, those skilled in the art may understand according to the method embodiments of the present disclosure.

In the several embodiments provided in the present disclosure, it should be understood that the disclosed device and method may be realized in other manners. The device embodiments described above are merely exemplary. All functional modules or units in the embodiments of the present disclosure may all be integrated in one processing unit, or each unit may be used as a single unit. Two or more units may be integrated in one. The above integrated unit can either be implemented in the form of hardware, or in the form of hardware combined with software functional units.

Persons of ordinary skill in the art should understand that, all or a part of steps of implementing the foregoing method embodiments may be implemented by related hardware of a computer instruction program. The instruction program may be stored in a computer-readable storage medium, and when executed, a processor executes the steps of the above method embodiments as stated above. The foregoing storage medium may include various types of storage media, such as a removable storage device, a read only memory (ROM) , a random-access memory (RAM) , a magnetic disk, or any media that stores program code.

Alternatively, when the above-mentioned integrated units of the present disclosure are implemented in the form of a software functional module being sold or used as an independent product, the integrated unit may also be stored in a computer-readable storage medium. Based on this understanding, the technical solutions provided by the embodiments of the present disclosure essentially or partially may be embodied in the form of a software product stored in a storage medium. The storage medium stores instructions which are executed by a computer device (which may be a personal computer, a server, a network device, or the like) to realize all or a part of the embodiments of the present disclosure. The above-mentioned storage medium may include various media capable of storing program codes, such as a removable storage device, a read only memory (ROM) , a random-access memory (RAM) , a magnetic disk, or an optical disk.

Logic when implemented in software, can be written in an appropriate language such as but not limited to C#or C++, and can be stored on or transmitted through a computer-readable storage medium (e.g., that is not a transitory signal) such as a random access memory (RAM) , read-only memory (ROM) , electrically erasable programmable read-only memory (EEPROM) , compact disk read-only memory (CD-ROM) or other optical disk storage such as digital versatile disc (DVD) , magnetic disk storage or other magnetic storage devices including removable thumb drives, etc.

The foregoing descriptions are merely embodiments of the present disclosure, and the protection scope of the present disclosure is not limited thereto. The scope that anyone skilled in the art may easily conceive changes and substitutions within the technical scope disclosed in the present disclosure that should be covered by the present disclosure. Therefore, the protection scope of the present disclosure should be subject to the scope of the claims as listed in the following.

Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure provided herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the disclosure being indicated by the claims.

Claims

A load switch circuit, comprising:

a switch unit and a first resistor, wherein:

an input of the switch unit is connected to an anode of a battery, an output of the switch unit is connected to an input of a load, an enable of the switch unit is connected to a first terminal of the first resistor, and a second terminal of the first resistor is connected to the ground; and

the enable of the switch unit is configured to:

control the switch unit to be turned on to allow the battery to supply power to the load; and

control the switch unit to be turned off to prevent the load from reversely charging the battery.
The load switch circuit according to claim 1, wherein the switch unit comprises: a first switching element and a first diode, wherein:

an input of the first switching element is connected to the anode of the battery, an output of the first switching element is connected to the input of the load, an enable of the first switching element is connected to the first terminal of the first resistor and an anode of the first diode, a cathode of the first diode is connected to the input of the load, and the enable of the first switching element is the enable of the switch unit; and

the enable of the first switching element is configured to:

control the first switching element to be turned on to allow the battery to supply power to the load;

control the first switching element to be turned off to prevent the load from reversely charging the battery; and

control the first diode to be turned on and off.
The load switch circuit according to claim 2, wherein the first switching element is a P-channel Metal Oxide Semiconductor (PMOS) transistor.
The load switch circuit according to claim 1, further comprising: a second diode, wherein:

an anode of the second diode is connected to the second terminal of the first resistor, a cathode of the second diode is connected to the output of the switch unit, and the cathode of the second diode is connected to the input of the load.
The load switch circuit according to claim 1, wherein the switch unit comprises: a second switching element and a second resistor, wherein:

an input of the second switching element is connected to the anode of the battery, an output of the second switching element is connected to the input of the load, an enable of the second switching element is connected to a first terminal of the second resistor, a second terminal of the second resistor is connected to the first terminal of the first resistor, and the second terminal of the second resistor is the enable of the switch unit; and

the enable of the switch unit is configured to control the second switching element to be turned on to allow the battery to supply power to the load; and control the second switching element to be turned off to prevent the load from reversely charging the battery.
The load switch circuit according to claim 5, wherein the second switching element is a positive-negative-positive (PNP) type triode.
The load switch circuit according to claim 1, wherein the switch unit comprises: a third switching element, a fourth switching element, a third resistor, a fourth resistor, and a fifth resistor; wherein:

an enable of the third switching element is respectively connected to a first terminal of the third resistor and a first terminal of the fourth resistor,

an input of the third switching element is respectively connected to an enable of the fourth switching element and a first terminal of the fifth resistor,

an output of the third switching element, an output of the fourth switching element, and a second terminal of the fourth resistor are respectively connected to the cathode of the battery,

a second terminal of the fifth resistor is respectively connected to the anode of the battery and the input of the load,

an input of the fourth switching element is connected to the ground,

a second terminal of the third resistor is connected to the first terminal of the first resistor and is the enable of the switch unit; and

the enable of the switch unit is configured to: control the third switching element to be turned off and the fourth switching element to be turned on to allow the battery to supply power to the load; and control the third switching element to be turned on and the fourth switching element to be turned off to prevent the load from reversely charging the battery.
The load switch circuit according to claim 7, wherein the third switching element is a negative-positive-negative (NPN) type triode, and the fourth switching element is an NPN type triode.
A battery assembly comprising: a battery and a load switch circuit, wherein:

the load switch circuit comprises a switch unit and a first resistor,

an input of the switch unit is connected to an anode of the battery, an output of the switch unit is connected to an input of a load, an enable of the switch unit is connected to a first terminal of the first resistor, and a second terminal of the first resistor is connected to the ground; and

the enable of the switch unit is configured to: control the switch unit to be turned on to allow the battery to supply power to the load; and control the switch unit to be turned off to prevent the load from reversely charging the battery.
A multi-power system comprising: one or more battery assemblies, an analog-to-digital converter, and a controller, wherein:

each of the one or more battery assemblies comprises a battery and a load switch circuit, wherein:

the load switch circuit comprises a switch unit and a first resistor,

an input of the switch unit is connected to an anode of the battery, an output of the switch unit is connected to an input of a load, an enable of the switch unit is connected to a first terminal of the first resistor, and a second terminal of the first resistor is connected to the ground; and

the enable of the switch unit is configured to: control the switch unit to be turned on to allow the battery to supply power to the load; and control the switch unit to be turned off to prevent the load from reversely charging the battery,

the anodes of the batteries in the one or more battery assemblies are respectively connected to an input of the analog-to-digital converter,

an output of the analog-to-digital converter is connected to an input of the controller, and

the controller is configured to compare power supply voltages of the one or more battery assemblies, select a battery assembly based on the power supply voltages, , and output an enabling signal to the enable of the selected battery assembly to allow the selected battery assembly to supply power for the load.