A circuit and terminal device for measuring current through a product external interface

Abstract

The application relates to a circuit and terminal device for measuring current through a product external interface, which comprises an interface circuit and a power switch circuit, the interface circuit comprises a control unit J1, a DN1 signal pin in the control unit J1 is connected with a BATTL level in the power switch circuit, and a DP1 signal pin in the control unit J1 is connected with a BATT level in the power switch circuit. The power switch circuit comprises a triode Q4 and a triode Q5, an emitter in the triode Q4 is connected with the BATTL level in the power switch circuit, a base in the triode Q4 is connected with a collector in the triode Q5 through a resistor R8, a collector in the triode Q4 is connected with the BATT level in the power switch circuit, the collector in the triode Q5 is further connected with an EN signal port through a resistor R20, the EN signal port is grounded through a resistor R17 and a resistor R18, a base in the triode Q5 is connected in parallel between the resistor R17 and the resistor R18, and an emitter in the triode Q5 is grounded.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of current detection, and in particular to a circuit and terminal device for measuring current through a product external interface. BACKGROUND

[0002] In modern electronic devices, accurate measurement of current is crucial for ensuring stable operation and safety. Traditional current measurement methods often rely on complex circuit designs and expensive specialized instruments, which not only increase costs but also limit their application range. With the development of technology, the demand for directly measuring current through a product external interface is growing, especially in portable devices and battery-powered applications.

[0003] Although existing current measurement technologies meet certain needs to some extent, there are still some shortcomings, such as high circuit complexity, high cost, limited measurement accuracy, etc. In particular, when current measurement through a product external interface is required, existing technical solutions often struggle to balance simplicity, cost-effectiveness, and measurement performance. In addition, with the development of electronic devices towards miniaturization and integration, higher requirements are placed on the size and power consumption of current measurement circuits.

[0004] Therefore, in view of the above deficiencies, the present application provides a new solution. SUMMARY

[0005] The main purpose of the present application is to provide a circuit and terminal device for measuring current through a product external interface, which can realize the function of directly measuring current through a product external interface by combining an interface circuit and a power switch circuit.

[0006] To achieve the above purpose, the present application provides a circuit for measuring current through a product external interface, comprising: an interface circuit and a power switch circuit, the interface circuit comprising: a control unit J1, the DN1 signal pin and the DN2 signal pin in the control unit J1 are connected to the BATTL level in the power switch circuit, and the DP1 signal pin and the DP2 signal pin in the control unit J1 are connected to the BATT level in the power switch circuit.

[0007] The power switch circuit comprises: a triode Q4 and a triode Q5, the emitter of the triode Q4 is connected with a BATTL level in the power switch circuit, the base of the triode Q4 is connected with the collector of the triode Q5 through a resistor R8, and a resistor R13 is connected in parallel between the emitter and the base of the triode Q4, the collector of the triode Q4 is connected with a BATT level in the power switch circuit, the collector of the triode Q5 is also connected with an EN signal port through a resistor R20, the EN signal port is grounded through a resistor R17 and a resistor R18, the base of the triode Q5 is connected in parallel between the resistor R17 and the resistor R18, and the emitter of the triode Q5 is grounded.

[0008] Preferably, the power switch circuit further comprises: a MOS tube Q3, the drain of the MOS tube Q3 is connected with the BATT level, the source of the MOS tube Q3 is connected with the BATTL level, and the gate of the MOS tube Q3 is connected with the collector of the triode Q4 and grounded through a resistor R9.

[0009] Preferably, the resistor R10 is NC / OR.

[0010] Preferably, the BATT level is grounded through a capacitor C68, and the BATTL level is grounded through a capacitor C67.

[0011] Preferably, the interface circuit further comprises: a USB 5V, the USB 5V is connected with a VBUS signal pin in the control unit J1 and grounded through a capacitor C5.

[0012] Preferably, the interface circuit further comprises: a diode Z1, the negative electrode of the diode Z1 is connected with the USB 5V, and the positive electrode of the diode Z1 is grounded.

[0013] Preferably, a CCl signal pin in the control unit J1 is grounded through a resistor R21, and a CC2 signal pin in the control unit J1 is grounded through a resistor R15.

[0014] In addition, a terminal device is also provided, and the terminal device is provided with the above-mentioned circuit for measuring current through a product external interface.

[0015] The technical scheme of the present application has the following beneficial effects:

[0016] When the DN1 and DN2 signal pins of the control unit J1 output high level, the base of the transistor Q4 receives a high level signal, so that the transistor Q4 is turned on. Since the emitter of the transistor Q4 is connected to the BATTL level and the collector is connected to the BATT level, when the transistor Q4 is turned on, a path is formed between the BATTL level and the BATT level, current flows, and the base of the transistor Q5 is grounded through resistors R17 and R18, while the collector is connected to the EN signal port through resistor R20. When the transistor Q4 is turned on, the collector voltage drops, causing the base voltage of the transistor Q5 to also drop, thereby turning on the transistor Q5. The conduction of the transistor Q5 further strengthens the path between the BATTL level and the BATT level, making the current measurement more stable.

[0017] At the same time, resistors R8 and R13 are connected between the base and emitter of the transistor Q4, and between the collector of the transistor Q5 and the signal pin of the control unit J1, respectively, to limit the size of the current and protect the circuit from excessive current. Further, when current flows through the BATTL level and the BATT level, a certain voltage drop is generated at the EN signal port, and the voltage change in the circuit is monitored through the EN signal port grounded by resistors R17 and R18, to real-time understand the change of the current. If the current exceeds the preset safety range, appropriate measures can be taken by the control unit J1, such as cutting off the power supply or issuing an alarm, to protect the safety of the circuit and the equipment. BRIEF DESCRIPTION OF DRAWINGS

[0018] Fig. 1 The USB interface circuit schematic diagram provided by an embodiment of the present application.

[0019] Fig. 2 The power switch circuit schematic diagram provided by an embodiment of the present application.

[0020] The implementation, functional features and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION

[0021] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference signs represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by reference to the accompanying drawings are exemplary and are intended to explain the present application, and cannot be understood as limiting the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0022] In addition, if the description in the present application involves "first", "second", etc., it is only for the purpose of description (such as for distinguishing the same or similar elements), and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first", "second" can be explicitly or implicitly included at least one of the features. In addition, the technical solutions of various embodiments can be combined with each other, but it must be based on the realization of ordinary skilled in the art, when the combination of technical solutions appears contradictory or cannot be realized, it should be considered that the combination of technical solutions does not exist, also not within the protection scope required by the present application.

[0023] Reference Figs. 1-2 The present application provides a circuit for measuring current through the external interface of the product, comprising: interface circuit and power switch circuit, the interface circuit comprises: control unit J1, the DN1 signal pin in the control unit J1 is connected with the DN2 signal pin, and the BATTL level in the power switch circuit is connected with the DP1 signal pin in the control unit J1, and the DP2 signal pin in the control unit J1 is connected with the BATT level in the power switch circuit.

[0024] The power switch circuit comprises: triode Q4 and triode Q5, the emitter of the triode Q4 is connected with the BATTL level in the power switch circuit, the base of the triode Q4 is connected with the collector of the triode Q5 through the resistance R8, and the resistance R13 is connected in parallel between the emitter and the base of the triode Q4, the collector of the triode Q4 is connected with the BATT level in the power switch circuit, the collector of the triode Q5 is also connected with the EN signal port through the resistance R20, the EN signal port is grounded through the resistance R17 and the resistance R18, the base of the triode Q5 is connected in parallel between the resistance R17 and the resistance R18, and the emitter of the triode Q5 is grounded.

[0025] In the present application, through the DN1 and DN2 signal pins and the DP1 and DP2 signal pins of the control unit J1, the control of the BATTL level and the BATT level in the power switch circuit is realized. When the control unit J1 outputs high level, the triodes Q4 and Q5 are turned on, so that the path between the BATTL level and the BATT level is formed, thereby realizing the measurement of current. At the same time, by adjusting the resistance values of the resistances R8, R13, R20, R17 and R18, the conduction degree of the triodes Q4 and Q5 is changed, so as to adjust the size of the current. And by monitoring the voltage change of the EN signal port, the change of the current can be known in real time, so as to carry out corresponding control and protection.

[0026] Specifically, when the DN1 and DN2 signal pins of the control unit J1 output high level, the base of the transistor Q4 receives a high level signal, so that the transistor Q4 is turned on. Since the emitter of the transistor Q4 is connected to the BATTL level and the collector is connected to the BATT level, when the transistor Q4 is turned on, a path is formed between the BATTL level and the BATT level, current flows, and the base of the transistor Q5 is grounded through resistors R17 and R18, while the collector is connected to the EN signal port through resistor R20. When the transistor Q4 is turned on, the collector voltage drops, causing the base voltage of the transistor Q5 to also drop, thereby turning on the transistor Q5. The conduction of the transistor Q5 further strengthens the path between the BATTL level and the BATT level, making the current measurement more stable.

[0027] At the same time, resistors R8 and R13 are connected between the base and emitter of transistor Q4, and between the collector of transistor Q5 and the signal pin of control unit J1, respectively, to limit the size of the current and protect the circuit from excessive current. Further, when current flows through the BATTL level and the BATT level, a certain voltage drop is generated at the EN signal port, and the voltage change in the circuit is monitored through the EN signal port grounded by resistors R17 and R18, to real-time understand the change of the current. If the current exceeds the preset safety range, appropriate measures can be taken by the control unit J1, such as cutting off the power supply or issuing an alarm, to protect the safety of the circuit and equipment.

[0028] In one embodiment, the power switch circuit further comprises a MOS transistor Q3, the drain of which is connected to the BATT level, the source of which is connected to the BATTL level, and the gate of which is connected to the collector of the transistor Q4 and grounded through resistor R9.

[0029] In this scheme, by introducing MOS transistor Q3, the control ability and stability of the circuit are further enhanced.

[0030] Specifically, by connecting the gate of the MOS transistor Q3 to the collector of the transistor Q4 and grounding it through resistor R9, the on-off state of the MOS transistor Q3 is directly controlled by the collector voltage of the transistor Q4.

[0031] In one embodiment, the resistor R10 is NC / 0R.

[0032] By setting the resistor R10 to NC (Not Connected) or 0Ω (Ohm), flexible adjustment and optimization of the circuit are achieved.

[0033] Specifically, when the resistor R10 is set to NC, it means that this position is not connected to any resistor, so that the circuit part related to this resistor can be disconnected, facilitating troubleshooting or circuit modification. When the resistor R10 is set to 0Ω, it is equivalent to connecting a wire at this position, which can effectively short two nodes and change the working state of the circuit or achieve specific functional requirements.

[0034] In one embodiment, the BATT level is grounded through capacitor C68, and the BATTL level is grounded through capacitor C67.

[0035] In this scheme, by grounding the BATT level and the BATTL level through capacitors C68 and C67 respectively, high-frequency noise on the power line is effectively filtered out, improving the accuracy of current measurement.

[0036] In one embodiment, the interface circuit further includes a USB 5V connected to the VBUS signal pin in the control unit J1 and grounded through capacitor C5.

[0037] In this scheme, by introducing the USB 5V power supply, a stable voltage supply can be provided to ensure that the control unit J1 can work normally.

[0038] Specifically, when the USB interface is inserted into a computer or other USB host device, the USB 5V power supply will be provided to the control unit J1 through the VBUS signal pin. Capacitor C5 is connected in parallel between the VBUS signal pin and ground, which plays a role in decoupling and filtering, reducing power noise and interference, and improving the stability and reliability of the power supply.

[0039] In one embodiment, the interface circuit further includes a diode Z1, the negative electrode of which is connected to the USB 5V, and the positive electrode is grounded.

[0040] In this scheme, by introducing diode Z1, reverse voltage protection can be provided to prevent damage to the device due to reverse connection of the power supply. When the USB 5V is correctly connected, diode Z1 is in the off state and does not affect the normal operation of the circuit. However, if the USB 5V is incorrectly connected to a negative voltage, diode Z1 will be turned on, directing the current to the ground, thereby preventing the control unit J1 and other sensitive components from being damaged by reverse voltage.

[0041] Specifically, when the USB 5V power is correctly connected, i.e. the USB 5V is a positive voltage, the negative electrode of the diode Z1 is high level and the positive electrode is low level, at this time, the diode Z1 is in a reverse bias state and will not be turned on. However, if the USB 5V is incorrectly connected to a negative voltage, i.e. the USB 5V is a negative voltage, the negative electrode of the diode Z1 becomes low level and the positive electrode becomes high level, at this time, the diode Z1 is in a forward bias state and will be turned on. In this way, any current that may be caused by a reverse voltage will flow through the diode Z1 to the ground, thereby protecting the entire circuit.

[0042] In one embodiment, the CC1 signal pin in the control unit J1 is grounded through the resistor R21, and the CC2 signal pin in the control unit J1 is grounded through the resistor R15.

[0043] In this scheme, by grounding the CC1 and CC2 signal pins through resistors R21 and R15 respectively, the current detection function of the circuit can be realized.

[0044] In one embodiment, the resistor R15=5.1K, the resistor R21=5.1K, the resistor R17=10M, the resistor R18=10M, the capacitor C68=0.1uF, the capacitor C67=0.1uF, and the capacitor C5=0.1uF.

[0045] In addition, a terminal device is also provided, which is provided with the above-mentioned current measurement circuit through a product external interface.

[0046] It should be noted that in this document, the terms "comprising", "including", or any other variant thereof are intended to cover non-exclusive inclusion, so that processes, devices, articles or methods of improving the computational efficiency of sql large tables including a series of elements not only include those elements, but also include other elements not explicitly listed or inherent to such processes, devices, articles or methods of improving the computational efficiency of sql large tables. Without more limitations, the element defined by the statement "including a" does not exclude the presence of another identical element in the process, device, article or method of improving the computational efficiency of sql large tables including the element.

[0047] The above description is only the preferred embodiment of the present application, and does not limit the patent scope of the present application, and any equivalent structure or equivalent process transformation using the content of the specification and drawings, or direct or indirect application in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A circuit for measuring current through an external interface of a product, characterized by, Comprise: Interface circuit and power switch circuit, the interface circuit comprises: control unit J1, the DN1 signal pin in the control unit J1 is connected with the DN2 signal pin in the power switch circuit BATTL level, the DP1 signal pin in the control unit J1 is connected with the DP2 signal pin in the power switch circuit BATT level; The power switch circuit comprises: triode Q4 and triode Q5, the emitter of the triode Q4 is connected with the BATTL level in the power switch circuit, the base of triode Q4 is connected with the collector of triode Q5 through resistance R8, and resistance R13 is connected in parallel between the emitter and the base of triode Q4, the collector of triode Q4 is connected with the BATT level in the power switch circuit, the collector of triode Q5 is also connected with EN signal port through resistance R20, EN signal port is grounded through resistance R17 and resistance R18, the base of triode Q5 is connected in parallel between resistance R17 and resistance R18, the emitter of triode Q5 is grounded; The control unit J1 is TYPC16 chip.

2. A circuit for measuring current through an external interface of a product according to claim 1, wherein, The power switch circuit further comprises: MOS tube Q3, the drain of the MOS tube Q3 is connected with the BATT level, the source of the MOS tube Q3 is connected with the BATTL level, the gate of the MOS tube Q3 is connected with the collector of triode Q4 and grounded through resistance R9.

3. A circuit for measuring current through an external interface of a product according to claim 2, wherein, The resistance R20 is NC / 0Ω.

4. A circuit for measuring current through an external interface of a product according to claim 3, wherein, The BATT level is grounded through capacitor C68, and the BATTL level is grounded through capacitor C67.

5. The circuit for measuring current through an external interface of a product of claim 1, wherein, The interface circuit further comprises: USB 5V, the USB 5V is connected with the VBUS signal pin in the control unit J1 and grounded through capacitor C5.

6. A circuit for measuring current through an external interface of a product according to claim 5, wherein, The interface circuit further comprises: diode Z1, the negative electrode of the diode Z1 is connected with the USB 5V, and the positive electrode of the diode Z1 is grounded.

7. A circuit for measuring current through an external interface of a product according to claim 6, wherein, The CC1 signal pin in the control unit J1 is grounded through resistance R21, and the CC2 signal pin in the control unit J1 is grounded through resistance R15.

8. A terminal device, comprising: A circuit for measuring current through a product external interface is provided, which comprises any one of claims 1-7.

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