CN112311023B - Power control circuit and power control method - Google Patents

Abstract

The embodiment of the invention provides a power supply control circuit and a power supply control method. The power control circuit comprises a battery unit, a power controller and a switch circuit. The power controller is used for providing a control signal. The switching circuit is coupled between the battery cell and the power supply controller. The switching circuit includes a diode element. The diode element is used for receiving the control signal. The switching circuit cuts off a power transfer path of the battery cell in response to a voltage difference between the first and second terminals of the diode element.

Description

Power control circuit and power control method

technical field

The invention relates to a power control technology, in particular to a power control circuit and a power control method.

Background technique

With the increasing power consumption of electronic devices such as electric vehicles, the safety of battery modules has also been paid more and more attention. When the output current of the battery module is too large, the battery protection chip in the electronic device may activate a low-voltage protection mechanism to immediately stop the charging/discharging of the battery module to avoid danger. At present, most battery modules use high-power field effect transistors as switching circuits of the battery modules. However, in the low-voltage protection mechanism, if the current flowing through the high-power field effect transistor is large, the turn-off time of the high-power field effect transistor may be prolonged (for example, tens of thousands of seconds), resulting in high power field effect. damage to the effective transistor or other electronic components.

SUMMARY OF THE INVENTION

The present invention provides a power control circuit and a power control method, which can effectively improve the above problems.

Embodiments of the present invention provide a power control circuit, which includes a battery unit, a power controller, and a switch circuit. The power controller is used for providing control signals. The switch circuit is coupled between the battery unit and the power controller. The switching circuit includes a diode element. The diode element is used for receiving the control signal. The switch circuit cuts off the power transfer path of the battery cell in response to a voltage difference between the first terminal and the second terminal of the diode element.

An embodiment of the present invention further provides a power control method, which includes: providing a control signal by a power controller; receiving the control signal by a diode element; and responding to the difference between a first end and a second end of the diode element The voltage difference of the battery unit cuts off the power transmission path of the battery unit.

Based on the above, the diode element in the switching circuit can receive the control signal from the power supply controller. In certain cases, in response to a voltage difference between the first and second ends of the diode element, the power transfer path of the battery cell may be cut off. Thereby, the delay time of cutting off the power transmission path of the battery unit can be effectively reduced, thereby improving the protection efficiency of the switch circuit, the battery unit and/or the remaining electronic components in the electronic device.

In order to make the above-mentioned features and advantages of the present invention more obvious and easy to understand, the following embodiments are given and described in detail with the accompanying drawings as follows.

Description of drawings

FIG. 1 is a schematic diagram of a power control circuit according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a power control circuit according to an embodiment of the present invention;

3 is a schematic diagram of a power control circuit according to an embodiment of the present invention;

FIG. 4 is a flowchart of a power control method according to an embodiment of the present invention.

Description of reference numerals

10, 20, 30: Power control circuit

11: Battery unit

12, 22, 32: switch circuit

13: Power Controller

101: Power-consuming devices

102: Power Delivery Path

D1: Diode element

Q1, Q2(1), Q2(2): Transistors

31: Charging circuit

S401～S403: Steps

CS: control signal

CV: Control Voltage

GND: reference ground voltage

Detailed ways

FIG. 1 is a schematic diagram of a power control circuit according to an embodiment of the present invention. Referring to FIG. 1 , the power control circuit 10 can be installed in various electronic devices that are powered by the battery unit 11 to the power consuming device 101 , such as electric vehicles, notebook computers, or smart phones. Taking an electric vehicle as an example, the power consumption device 101 may be an electronic device driven by the power provided by the battery unit 11 , such as a vehicle instrument panel, a vehicle lamp, a power system and/or a braking system. Alternatively, taking a notebook computer as an example, the power consumption device 101 may be a display, a central processing unit, a memory module, a communication module and/or various functional circuits.

The power control circuit 10 includes a battery unit 11 , a switch circuit 12 and a power controller 13 . The battery unit 11 is used to perform a discharge operation to provide power to the power consumption device 101 . For example, the battery cells 11 may include nickel-cadmium (Ni-Cd) batteries, nickel-metal hydride (Ni-MH) batteries, lithium-ion (Li-lon) batteries, lithium-polymer (Li-polymer) batteries, and lead-acid (Sealed) batteries At least one of them, and the type of the battery unit 11 is not limited thereto. In addition, the number of batteries in the battery unit 11 may be one or more, which is not limited in the present invention.

The power controller 13 may include one or more chips (or chipsets). For example, power controller 13 may include a processor, or other programmable general or special purpose microprocessor, digital signal processor, programmable controller, application specific integrated circuit, programmable logic device or other similar devices or combinations of these devices. In one embodiment, the power controller 13 is also called a power management chip or a battery protection chip.

The switch circuit 12 is coupled between the battery unit 11 and the power controller 13 . The power controller 13 may provide the control signal CS to the switch circuit 12 . In particular, the power controller 13 can control the switch circuit 12 to turn on or off the power transmission path 102 of the battery unit 11 through the control signal CS. When the power transfer path 102 is turned on by the switch circuit 12 , the battery unit 11 can provide power to the power consumption device 101 via the power transfer path 102 . However, when the power transfer path 102 is cut off by the switch circuit 12 , the battery unit 11 cannot provide power to the power consumption device 101 via the power transfer path 102 .

In one embodiment, the power controller 13 may detect the current and/or voltage on the power delivery path 102 . The power controller 13 may determine whether to activate the low voltage protection mechanism, the high/low current protection mechanism, the temperature protection mechanism and/or the short circuit protection mechanism according to the detected current and/or voltage. At least one of the above protection mechanisms may be referred to as a power protection mechanism. Under normal circumstances, the power controller 13 can maintain the switch circuit 12 to conduct the power transmission path 102 through the control signal CS, so that the battery unit 11 can supply power to the power consumption device 101 normally.

However, when it is determined that the power protection mechanism needs to be activated (for example, when the current and/or voltage on the power transmission path 102 is abnormal), the power controller 13 can change the voltage level of the control signal CS to control the switch circuit 12 to cut off the power Delivery path 102 . For example, the power supply controller 13 may adjust the voltage level of the control signal CS from logic high to logic low. In response to the voltage level of the control signal CS being adjusted from a logic high to a logic low, the switch circuit 12 may cut off the power delivery path 102 . It should be noted that the speed and/or efficiency of the switching circuit 12 to cut off the power transfer path 102 is critical to the performance of the power protection mechanism and system safety. If the switching circuit 12 cuts off the power delivery path 102 slowly (eg, 63.4 milliseconds), some electronic components in the switching circuit 12 and/or the power consuming device 101 may be damaged before the power delivery path 102 is completely cut off.

In the present embodiment, the switch circuit 12 includes a diode element D1. The number of diode elements D1 may be one or more. The diode element D1 can receive the control signal CS. The switch circuit 12 may cut off the power transfer path 102 in response to a voltage difference between a first terminal (eg, an input terminal) and a second terminal (eg, an output terminal) of the diode element D1. For example, the switching circuit 12 may detect the voltage difference between the first terminal and the second terminal of the diode element D1. When the power controller 13 changes the voltage level of the control signal CS, the voltage difference across the diode element D1 will be greater than a critical value. At this time, according to the voltage difference, the switch circuit 12 can instantaneously cut off the power transmission path 102 .

In one embodiment, the switching circuit 12 may continuously compare the detected voltage difference to a threshold value. If the detected voltage difference is greater than the threshold value, it means that the power controller 13 has changed the voltage level of the control signal CS, so the switch circuit 12 can immediately cut off the power transmission path 102 . In some embodiments, it only takes about 0.5 to 6.05 microseconds to cut off the power transmission path 102 according to the voltage difference between the two ends of the diode element D1 , which greatly improves the cutting efficiency of the power transmission path 102 . However, if the detected voltage difference is not greater than the threshold value, the switch circuit 12 can maintain the power transmission path 102 in an on state.

In one embodiment, the switch circuit 12 further includes a transistor (also referred to as a first transistor) Q1. The transistor Q1 is coupled between the diode element D1 and the battery unit 11 , as shown in FIG. 1 . The transistor Q1 can be used to turn on or off the power transfer path 102 . For example, the transistor Q1 can be a high power metal oxide semiconductor field effect transistor (power MOSFET) or other electronic components with similar functions.

In one embodiment, the switch circuit 12 further includes a transistor (also referred to as a second transistor) Q2(1). The transistor Q2(1) is coupled between the diode element D1 and the transistor Q1, as shown in FIG. 1 . Transistor Q2(1) can detect the voltage difference across diode element D1 and change the control voltage CV of transistor Q1 in response to the voltage difference. Next, the transistor Q1 may cut off the power transfer path 102 in response to the change in the control voltage CV.

In the embodiment of FIG. 1, a bipolar junction transistor (BJT) is used as an example of the transistor Q2(1). The first terminal (eg base) and the second terminal (emitter) of the transistor Q2(1) are respectively coupled to the first terminal (eg input terminal) and the second terminal (eg output terminal) of the diode element D1 to detect the diode The voltage difference across element D1. In addition, the third terminal (eg, the collector) of the transistor Q2(1) is coupled to the reference ground voltage GND, as shown in FIG. 1 .

If the voltage difference across the diode element D1 is greater than a threshold value (eg, 0.8 to 0.9 volts), the transistor Q2(1) can be turned on in response to the voltage difference. The turned-on transistor Q2(1) can change the control voltage CV of the transistor Q1 according to the reference ground voltage GND. For example, when the transistor Q2(1) is turned on, the transistor Q2(1) can momentarily adjust the control voltage CV to be equal to or close to the reference ground voltage GND. At this time, the transistor Q1 can quickly cut off the power transmission path 102 .

FIG. 2 is a schematic diagram of a power control circuit according to an embodiment of the present invention. Referring to FIG. 2 , compared with the power control circuit 10 of FIG. 1 , in this embodiment, the power control circuit 20 includes a switch circuit 22 , and the transistor Q2 ( 2 ) in the switch circuit 22 is a P-type metal oxide semiconductor. Field effect transistor as an example. For other electronic components with the same reference numerals, reference may be made to the description of the embodiment in FIG. 1 , which will not be repeated here.

In this embodiment, the first terminal (eg gate) and the second terminal (source) of the transistor Q2(2) are respectively coupled to the first terminal (eg the input terminal) and the second terminal (eg the input terminal) of the diode element D1 output) to detect the voltage difference across the diode element D1. In addition, the third terminal (eg, the drain) of the transistor Q2 is coupled to the reference ground voltage GND, as shown in FIG. 2 .

If the voltage difference across the diode element D1 is greater than a threshold value (eg, 1 to 3 volts), the transistor Q2(2) can be turned on in response to the voltage difference. Once the transistor Q2(2) is turned on, the transistor Q2(2) can momentarily adjust the control voltage CV to be equal to or close to the reference ground voltage GND. In response to changes in the control voltage CV, the transistor Q1 can quickly cut off the power transfer path 102 .

In other words, in the embodiments of FIGS. 1 and 2 , when the power controller 13 changes the voltage level of the control signal CS, the voltage difference across the diode element D1 is greater than a threshold value. Once the voltage difference across the diode element D1 is greater than the threshold value, the transistor Q2(1) or Q2(2) can instantly pull the control voltage CV to approximately equal to the reference ground voltage GND, so that the transistor Q1 quickly cuts off the power transmission path 102. Therefore, when an abnormal situation occurs (such as abnormal voltage, current and/or temperature), the power controller 13 can quickly activate the power protection mechanism with almost no delay, effectively improving the performance of the switching circuit 12 (or 22) and/or Protection capability of the power consuming device 101 .

FIG. 3 is a schematic diagram of a power control circuit according to an embodiment of the present invention. Referring to FIG. 3 , compared with the embodiments of FIGS. 1 and 2 , in this embodiment, the power control circuit 30 further includes a charging circuit 31 . When the switch circuit 32 maintains the power transmission path 102 in an on state, the charging circuit 31 can charge the battery unit 11 via the power transmission path 102 .

However, when an abnormality occurs, the power controller 13 may change the control signal CS. In response to the change of the control signal CS, the switch circuit 32 can momentarily cut off the power transmission path 102 by referring to the ground voltage GND to activate the power protection mechanism. The related operation details can also be referred to the embodiments of FIG. 1 and FIG. 2 , which will not be repeated here. In addition, after the power transmission path 102 is cut off, the charging circuit 31 cannot charge the battery unit 11 .

It should be noted that although the number of transistors (eg transistor Q1 ) used as switches in the switch circuits 12 , 22 and 32 is all one in the foregoing embodiment, the present invention does not limit the switch circuit 12 in the foregoing embodiment , 22 and 32 the number of transistors (eg transistor Q1 ) used as switches. Taking FIG. 1 as an example, in one embodiment, if the number of transistors Q1 is multiple, these transistors Q1 can be connected to the power transmission path 102 in parallel, and the control voltage CV can be used to control each transistor Q1 to The power transmission path 102 is turned on or off.

It should be noted that, in the aforementioned embodiments, the cut-off of the power transmission path 102 does not need to be controlled by an additional control element (such as a microprocessor unit), thereby reducing the signal transmission delay and/or improving the cutting off of the power transmission path 102 s efficiency. In addition, instead of only connecting one or more resistors in series between the transistor Q1 and the reference ground voltage GND, in the aforementioned embodiment, the transistor Q2(1) or Q2(2) is connected in series between the transistor Q1 and the reference ground voltage GND between, the leakage current between the transistor Q1 and the reference ground voltage GND can be reduced.

FIG. 4 is a flowchart of a power control method according to an embodiment of the present invention. Referring to FIG. 4 , in step S401 , a control signal is provided by a power supply controller. In step S402, the control signal is received by a diode element. In step S403, the power transmission path of the battery cell is cut off in response to the voltage difference between the first end and the second end of the diode element.

However, each step in FIG. 4 has been described in detail as above, and will not be repeated here. It should be noted that each step in FIG. 4 can be implemented as a plurality of program codes or circuits, which is not limited in the present invention. In addition, the method of FIG. 4 can be used in conjunction with the above exemplary embodiments, and can also be used alone, which is not limited in the present invention.

To sum up, the diode element disposed in the switch circuit can receive the control signal from the power supply controller. In certain cases, in response to a voltage difference between the first and second ends of the diode element, the power transfer path of the battery cell may be cut off. Thereby, the delay time of cutting off the power transmission path of the battery unit can be effectively reduced, thereby improving the protection efficiency of the switch circuit, the battery unit and/or the remaining electronic components in the electronic device.

Although the present invention has been disclosed above with examples, it is not intended to limit the present invention. Any person skilled in the art can make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, the present invention The scope of protection shall be subject to what is defined in the claims.

Claims (6)

1. A power supply control circuit, comprising: battery unit; a power controller for providing control signals; and a switch circuit, coupled between the battery unit and the power controller, The switch circuit includes a diode element, a first transistor and a second transistor, the first transistor is coupled between the diode element and the battery unit, and the second transistor is coupled between the diode element and the battery unit between the first transistor, the diode element is used for receiving the control signal, the second transistor to detect a voltage difference across the diode element and to vary the control voltage of the first transistor in response to the voltage difference, and The first transistor cuts off the power transfer path of the battery cell in response to the change in the control voltage. 2. The power control circuit of claim 1, wherein a first end and a second end of the second transistor are respectively coupled to the first end and the second end of the diode element to detect the said voltage difference, The third terminal of the second transistor is coupled to the reference ground voltage, the second transistor is turned on in response to the voltage difference, and The turned-on second transistor changes the control voltage of the first transistor according to the reference ground voltage. 3. The power control circuit of claim 1, wherein the switch circuit cuts off the power transfer path of the battery cell in response to the voltage difference being greater than a threshold value. 4. A power control method, comprising: The control signal is provided by the power controller; receiving the control signal by a diode element; detecting, by a second transistor, a voltage difference across the diode element and changing the control voltage of the first transistor in response to the voltage difference; and The power transfer path of the battery cell is cut off in response to the change of the control voltage by a first transistor coupled between the diode element and the battery cell, and the second transistor coupled to the diode between the element and the first transistor. 5. The power control method of claim 4, wherein the step of changing the control voltage of the first transistor by the second transistor in response to the voltage difference comprises: detecting the voltage difference by the first terminal and the second terminal of the second transistor; receiving a reference ground voltage from the third terminal of the second transistor; turning on the second transistor in response to the voltage difference; and The control voltage of the first transistor is changed according to the reference ground voltage by the turned-on second transistor. 6. The power control method of claim 4, wherein the power delivery of the battery cell is cut off in response to the voltage difference between the first end and the second end of the diode element The steps of the path include: The power delivery path of the battery cell is cut off in response to the voltage difference being greater than a threshold value.

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