Battery voltage detection circuit
The battery voltage detection circuit controlled by a combination of transistors and PMOS transistors overcomes the limitations of traditional circuits in terms of detection accuracy and power consumption in low-power applications, achieving accurate battery voltage detection under low-power conditions. It is suitable for automated control systems and smart home devices.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-24
- Publication Date
- 2026-03-31
AI Technical Summary
Traditional battery voltage detection circuits have limitations in terms of detection accuracy and power consumption in low-power applications, and cannot meet the requirements for long-term stable operation.
A battery voltage detection circuit using a combination of transistors and PMOS transistors controls the switching on and off of the PMOS transistor by adjusting the state of the transistor, thereby achieving accurate detection of the battery voltage and maintaining extremely low static power consumption when the PMOS transistor is on.
It enables accurate detection of battery voltage under low power conditions, making it suitable for low-power electronic devices such as automated control systems and smart home devices.
Smart Images
Figure CN224066885U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of detection circuit technology, and in particular to a battery voltage detection circuit. Background Technology
[0002] In battery-powered electronic devices, real-time monitoring of battery voltage is crucial for ensuring stable operation and extending battery life. Traditional battery voltage detection circuits often employ direct resistor voltage division, but this method has limitations in terms of detection accuracy and power consumption. Especially in applications requiring low power consumption, traditional circuits may not meet the demands for long-term stable operation.
[0003] Therefore, it is necessary to provide a battery voltage detection circuit that is simple in structure, low in power consumption, and has high detection accuracy, making it suitable for practical needs. Utility Model Content
[0004] This utility model discloses a battery voltage detection circuit, which relates to the field of automatic control, and in particular to the low power consumption design of smart home devices, which can effectively solve the technical problems involved in the background art.
[0005] To achieve the above objectives, the technical solution of this utility model is as follows:
[0006] A battery voltage detection circuit includes a port MCU Control. The port MCU Control is connected to one end of a resistor R1. The other end of the resistor R1 is connected to one end of a resistor R2 and the base of a transistor Q1. The other end of the resistor R2 is connected to port GND. The emitter of the transistor Q1 is connected to port GND. The collector of the transistor Q1 is connected to one end of a resistor R4. The other end of the resistor R4 is connected to one end of a resistor R3 and the gate of a MOSFET Q2. The other end of the resistor R3 is connected to the source of the MOSFET Q2 and port VBAT. The drain of the MOSFET Q2 is connected to one end of a resistor R5. The other end of the resistor R5 is connected to one end of a resistor R6, one end of a capacitor C1, and port ADC. The other end of the resistor R6 is connected to the other end of the capacitor C1 and port GND.
[0007] A battery voltage detection circuit using a combination of transistors and PMOS transistors is disclosed. By adjusting the state of the transistor in the circuit to control the on / off state of the PMOS transistor, effective detection of battery voltage is achieved, maintaining extremely low static power consumption during on-detection and zero standby power consumption during off-detection. This circuit is suitable for applications in low-power electronic devices requiring battery voltage monitoring, such as automated control systems and smart home devices. It includes: 1. A battery input module: used to input the battery voltage to be detected, including a positive battery input terminal and a negative battery input terminal. 2. A transistor control module: including a transistor whose base is connected to the control signal input terminal through a resistor, its emitter is grounded, and its collector is connected to the gate of the PMOS transistor; by adjusting the resistor value and the type of transistor, the conduction state of the transistor can be precisely controlled, thereby achieving precise control of the PMOS transistor's on / off state. 3. PMOS Transistor Driver Module: This module includes a PMOS transistor whose gate is connected to the output of the transistor control module, its source is connected to the positive input terminal of the battery, and its drain is connected to the voltage detection module. When the transistor is turned on, the gate voltage of the PMOS transistor decreases, the PMOS transistor conducts, and the battery voltage is transmitted to the voltage detection module through the PMOS transistor. When the transistor is turned off, the gate voltage of the PMOS transistor increases, the PMOS transistor is turned off, and the battery voltage is disconnected from the voltage detection module. 4. Voltage Detection Module: This module detects the battery voltage output from the drain of the PMOS transistor and converts it into a processable electrical signal. It may include a voltage divider circuit, a filter circuit, and an analog-to-digital converter to achieve accurate measurement and digital processing of the battery voltage.
[0008] As a preferred improvement of this utility model: the MCU Control port is connected to the control pin of the microcontroller.
[0009] As a preferred improvement of this utility model, the port ADC is connected to the sampling pin of the microcontroller.
[0010] As a preferred improvement of this utility model: the VBAT port is connected to the positive terminal of the battery under test, and the negative terminal of the battery under test is grounded.
[0011] As a preferred improvement of this utility model, the MOS transistor Q2 is a PMOS transistor.
[0012] As a preferred improvement of this utility model: the resistance of resistor R1 is 10K, the resistance of resistor R2 is 100K, the resistance of resistor R4 is 10K, and the resistance of resistor R5 is 30K.
[0013] The beneficial effects of this utility model are as follows:
[0014] A battery voltage detection circuit based on transistor and PMOS control is provided to solve the technical problems mentioned in the background art. This circuit achieves accurate detection of battery voltage by precisely controlling the switching of PMOS transistor through transistor, while maintaining extremely low static power consumption. This circuit is suitable for application scenarios in low-power electronic devices that require battery voltage monitoring, such as automatic control systems and smart home devices. Attached Figure Description
[0015] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort, wherein:
[0016] Figure 1 This is a schematic diagram of a battery voltage detection circuit according to the present invention. Detailed Implementation
[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.
[0018] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.
[0019] Furthermore, in this invention, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.
[0020] In this invention, unless otherwise explicitly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.
[0021] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.
[0022] Please see Figure 1 As shown, this utility model provides a battery voltage detection circuit, including a port MCU Control. The port MCU Control is connected to one end of resistor R1. The other end of resistor R1 is connected to one end of resistor R2 and the base of transistor Q1. The other end of resistor R2 is connected to port GND. The emitter of transistor Q1 is connected to port GND. The collector of transistor Q1 is connected to one end of resistor R4. The other end of resistor R4 is connected to one end of resistor R3 and the gate of MOSFET Q2. The other end of resistor R3 is connected to the source of MOSFET Q2 and port VBAT. The drain of MOSFET Q2 is connected to one end of resistor R5. The other end of resistor R5 is connected to one end of resistor R6, one end of capacitor C1, and port ADC. The other end of resistor R6 is connected to the other end of capacitor C1 and port GND. In this embodiment, the MCUControl port is connected to the control pin of the microcontroller, the ADC port is connected to the sampling pin of the microcontroller, the VBAT port is connected to the positive terminal of the battery under test, the negative terminal of the battery under test is grounded, the MOS transistor Q2 is a PMOS transistor, the resistor R1 has a resistance of 10K, the resistor R2 has a resistance of 100K, the resistor R4 has a resistance of 10K, and the resistor R5 has a resistance of 30K.
[0023] Specifically, a battery voltage detection circuit based on transistor and PMOS transistor control includes a battery access module, a transistor control module, a PMOS transistor drive module, and a voltage detection module.
[0024] The battery access module requires an externally connected battery to be tested. The positive terminal of the battery is connected to the battery voltage detection input terminal VBAT, and the negative terminal of the battery is directly grounded.
[0025] The transistor control module is connected to one end of the first voltage divider resistor R1 via the microcontroller's I / O, and the other end of resistor R1 is connected to the base of the first transistor Q1. One end of the second voltage divider resistor R2 is connected to the first voltage divider resistor R1, and the other end of resistor R2 is grounded.
[0026] The gate of the PMOS driving module is connected to one end of the fourth current-limiting resistor R4 and to the collector of the transistor Q1. It is also connected to one end of the third current-limiting resistor R3 and connected to the positive terminal of the battery. The source of the PMOS transistor Q2 is connected to the positive terminal of the battery, and the drain is grounded through the fifth resistor R5 and the sixth resistor R6 in series.
[0027] The analog-to-digital conversion module samples the battery voltage from the voltage divider network formed by the fifth resistor R5 and the sixth resistor R6. The sampling port performs filtering processing and uses the ADC sampling port of the microcontroller to convert the analog battery voltage signal into a digital signal for processing by the microcontroller or other digital circuits.
[0028] Working principle:
[0029] 1. Detection Status: When the MCU_Control outputs a high level, the first transistor Q1 and the first MOSFET Q2 are turned on. The fifth resistor R5 and the sixth resistor R6 are connected to the battery VBAT to form a discharge circuit, allowing the MCU_ADC to detect the battery voltage. To prevent the gate of the first MOSFET Q2 from being subjected to a reverse voltage from the battery exceeding its maximum gate-source voltage (GS), a suitable fourth voltage divider resistor R4 is added for voltage limiting.
[0030] 2. Off state: When the MCU_Control output is low or the MCU is completely powered off, the second resistor R2 pulls the base of the first transistor Q1 to ground, the first transistor Q1 is turned off, the first MOSFET Q2 is turned off, and the fifth resistor R5 and the sixth resistor R6 are disconnected from the battery VBAT.
[0031] Although the embodiments of this utility model have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for this utility model. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, this utility model is not limited to the specific details and the illustrations shown and described herein.
Claims
1. A battery voltage detection circuit, characterized by: The port MCU Control is connected to a control pin of the single-chip microcomputer.
2. The battery voltage detection circuit according to claim 1, characterized by: The port ADC is connected to a sampling pin of the single-chip microcomputer.
3. The battery voltage detection circuit of claim 1, wherein: The port VBAT is connected to a positive electrode of the battery to be measured, and a negative electrode of the battery to be measured is grounded.
4. The battery voltage detection circuit of claim 1, wherein: The MOS tube Q2 is a PMOS tube.
5. The battery voltage detection circuit of claim 1, wherein: The resistance R1 has a resistance value of 10K, the resistance R2 has a resistance value of 100K, the resistance R4 has a resistance value of 10K, and the resistance R5 has a resistance value of 30K.
6. The battery voltage detection circuit of claim 1, wherein: