Current detection circuit and electronic device for power supply channel

Abstract

The present invention provides a current detection circuit and electronic device for a power supply channel, wherein the current detection circuit comprises: a parallel branch, a current detection module and a control module; the parallel branch is connected in parallel to the two ends of the first field effect tube; the control module is connected to the gate of the first field effect tube, and is used to control the first field effect tube to be turned off when the normal working current information of the power supply channel needs to be determined; the parallel branch can remain turned on when the normal working current information needs to be determined; the current detection module is connected to the parallel branch, and is used to detect the current information of the parallel branch, so that the normal working current information can be determined according to the current information of the parallel branch when the first field effect tube is turned off and the parallel branch is turned on. While realizing effective detection, the present invention can avoid connecting a current detection resistor in series with the power supply channel, thereby reducing the power consumption and heat of the power supply channel.

Description

Technical Field

[0001] The invention relates to a rechargeable electronic device, and in particular to a current detection circuit of a charging circuit and the electronic device. Background Art

[0002] In electronic devices, power can be supplied to loads through a power channel, wherein circuit devices can be used to manage the current path of the power channel. For example, in a mobile phone, direct charging path management can be implemented through relevant circuit devices.

[0003] In order to be suitable for management, the current information of the power supply channel needs to be detected. Furthermore, in order to detect the current information of the power supply channel, a current sensing resistor is usually set in the power supply channel, and the current sensing resistor is connected in series with the load. Then, the current sensing amplifier can be used to sample the current information of the current sensing resistor to obtain a voltage signal used to characterize the current information, and the voltage signal is amplified, and then the amplified signal is converted into an analog-to-digital converter so that it can be acquired by the logic control module.

[0004] In this process, since the load needs to be connected in series with the current-sense resistor, it will cause the impedance of the power supply channel to be larger, which is easy to cause power loss due to the current-sense resistor, and the heat dissipation of the power supply channel will increase due to the power consumption of the current-sense resistor. Summary of the invention

[0005] The invention provides a current detection circuit of a power supply channel and an electronic device to solve the problem generated when a current detection resistor is used to detect the power supply channel.

[0006] According to a first aspect of the present invention, a current detection circuit of a power supply channel is provided, wherein the power supply channel comprises a power supply input terminal, a first field effect transistor and a load connected in sequence, and the current detection circuit comprises: a parallel branch, a current detection module and a control module; the parallel branch is connected in parallel to both ends of the first field effect transistor;

[0007] The control module is connected to the gate of the first field effect transistor, and is used to control the first field effect transistor to be turned off when the normal working current information of the power supply channel needs to be determined;

[0008] The parallel branch can remain conductive when the normal operating current information needs to be determined;

[0009] The current detection module is connected to the parallel branch and is used to detect current information of the parallel branch, so that the normal operating current information can be determined according to the current information of the parallel branch when the first field effect transistor is turned off and the parallel branch is turned on.

[0010] Optionally, a second field effect transistor is provided in the parallel branch, and the second field effect transistor can remain turned on when the normal operating current information needs to be determined.

[0011] Optionally, the current detection module includes a mirror field effect transistor that is proportional to the size of the second field effect transistor, and an analog-to-digital converter, the mirror field effect transistor is connected in series with a configured resistor, and one end of the resistor that is not connected to the mirror field effect transistor is grounded, and the analog-to-digital converter can collect the voltage drop of the resistor for characterizing current information.

[0012] Optionally, the impedance generated by the first field effect transistor is smaller than the impedance generated by the parallel branch.

[0013] Optionally, the control module includes a charge pump control unit, and an output end of the charge pump control unit is connected to the gate of the first field effect transistor to control the first field effect transistor to be turned off when the normal operating current information of the power supply channel needs to be determined.

[0014] Optionally, the current detection module is also connected to a data processing module, and the data processing module is used to obtain current information of the parallel branch when the first field effect transistor is turned off and the parallel branch is turned on, and determine the normal operating current information based on the current information.

[0015] Optionally, the control module is further connected to a gate of a third field effect transistor, and the third field effect transistor is arranged in the power supply channel and between the first field effect transistor and the load.

[0016] Optionally, the control module is further connected to the parallel branch, for:

[0017] The parallel branch is controlled to remain conductive during normal operation and when the normal operating current information needs to be determined.

[0018] Optionally, the control module is further connected to the parallel branch, for:

[0019] When the voltage at the power input end is over-voltage or under-voltage, the parallel branch is controlled to be turned off.

[0020] Optionally, the control module is further used to: control the first field effect transistor to be turned on during normal operation.

[0021] According to a second aspect of the present invention, an electronic device is provided, comprising the current detection circuit and the power supply channel involved in the first aspect and its optional solutions.

[0022] In the current detection circuit and electronic device of the power supply channel provided by the present invention, the current detection resistor is avoided to be connected in series with the power supply channel, and a parallel branch connected in parallel with the first field effect tube is adopted. When the normal working current information needs to be detected, the present invention can control the first field effect tube to be turned off through the control module, and the parallel branch can remain turned on, and the current enters the load through the parallel branch. At this time, the current information of the parallel branch can be associated with the normal working current information during normal operation (that is, when the first field effect tube and the parallel branch are both turned on). Furthermore, the normal working current information can be determined based on the current information when the parallel branch is turned on alone. For example, when the impedance of the first field effect tube and the parallel branch is small enough, it can be ignored relative to the load. At this time, the current information measured when the parallel branch is turned on alone can be used as the normal working current information.

[0023] The present invention realizes effective detection of the current of the power supply channel based on the parallel branch, the current detection module and the control module. While realizing the effective detection, it can avoid connecting the current detection resistor in series with the power supply channel, thereby reducing the power consumption and heat of the power supply channel.

[0024] At the same time, since the impedance of the parallel branch does not need to be very small, on the one hand, it is easy to obtain higher current measurement accuracy, and on the other hand, the selection range of devices in the current detection module will not be limited due to the small current detection resistance, and thus it can be suitable for using lower cost devices. It can be seen that the present invention can also facilitate taking into account both detection accuracy and cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0026] Figure 1 FIG. 1 is a schematic diagram of the structure of a power supply channel and a current detection circuit in an embodiment of the present invention. Figure 1 ;

[0027] Figure 2 FIG. 1 is a schematic diagram of the structure of a power supply channel and a current detection circuit in an embodiment of the present invention. Figure 2 ;

[0028] Figure 3 FIG. 1 is a schematic diagram of the structure of a power supply channel and a current detection circuit in an embodiment of the present invention. Figure 3 ;

[0029] Figure 4 FIG. 1 is a schematic diagram of the structure of a power supply channel and a current detection circuit in an embodiment of the present invention. Figure 4 ;

[0030] Figure 5 Schematic diagram of a power supply channel and a current detection circuit in one embodiment of the present invention.

[0031] Description of reference numerals:

[0032] 1-Current detection circuit;

[0033] 11- control module;

[0034] 111-charge pump control unit;

[0035] 12-parallel branch;

[0036] 121, N 2 - Second field effect transistor;

[0037] 13-current detection module;

[0038] 2- Power channel;

[0039] 21. N 1 - The first field effect transistor;

[0040] 22. VIN-power input terminal;

[0041] 23. R load -load;

[0042] 24. N 3 - The third field effect transistor;

[0043] CSA - Current Sense Amplifier;

[0044] ADC - Analog to Digital Converter. DETAILED DESCRIPTION

[0045] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0046] The terms "first", "second", "third", "fourth", etc. (if any) in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0047] The technical solution of the present invention is described in detail with specific embodiments below. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described in detail in some embodiments.

[0048] Figure 1 FIG. 1 is a schematic diagram of the structure of a power supply channel and a current detection circuit in an embodiment of the present invention. Figure 1 .

[0049] Please refer to Figure 1 , provides a current detection circuit for a power channel, wherein the power channel 2 includes a power input terminal 22, a first field effect transistor 21 and a load 23 connected in sequence.

[0050] The power channel 2 can be understood as any circuit structure that can supply power from the power input terminal 22 to the load 23, wherein the first field effect transistor 21 can be configured to control the on-off between the power input terminal 22 and the load 23. At the same time, this embodiment does not exclude the solution that the power channel 2 is also provided with at least one other device such as a switch, a resistor, etc., wherein the switch can be, for example, another field effect transistor.

[0051] In actual use, in some scenarios, it may be necessary to detect the current of power channel 2. The following describes this scenario using a mobile phone as an example of an electronic device:

[0052] In the direct charging path management of mobile phones, the current path often needs to be controlled to be turned on and off, and even needs to support bidirectional shutdown and specified unidirectional conduction functions. The device that performs this function can be, for example, the first field effect transistor 21 mentioned above and / or the third field effect transistor 24 mentioned later. At the same time, the power channel 2 can refer to the current path mentioned above. Furthermore, in some scenarios, the power supply, charging speed, and heating conditions can be optimized by managing the power channel 2 (for example, the on-off control of the first field effect transistor 21). Therefore, in order to manage charging or power supply safety, adjust the charging speed, and understand the power transmission situation, etc., the current of the power channel 2 needs to be detected.

[0053] In view of this, in the existing related technology, the control of the field effect transistor in the power channel 2 and the detection of the current information are respectively achieved through different devices.

[0054] The number of power supply channels 2 in the electronic device may be one, and the implementation mode of having more than one power supply channels 2 is not excluded. Correspondingly, the same current detection circuit may be used for detection, or different current detection circuits may be used for detection.

[0055] The first field effect transistor 21 can be any field effect transistor.

[0056] The load 23 can be understood as any device or a collection of devices in the electronic device that needs to be provided with electrical energy. In a specific implementation, the load 23 can include, for example, an electrical device module and / or an energy storage module. The end of the load 23 away from the first field effect transistor 21 can be directly or indirectly grounded.

[0057] The power input terminal 22 can be understood as any circuit node that can supply power to the load, and its front end can be connected to the external power supply interface of the electronic device, and can also be connected to an energy storage device, and can also be connected to any other device or equipment that can provide power to it.

[0058] In this embodiment, the current detection circuit 1 includes: a parallel branch 12 , a current detection module 13 and a control module 11 . The parallel branch 12 is connected in parallel to two ends of the first field effect transistor 21 .

[0059] It can be seen that the above embodiments can avoid connecting a current-sense resistor in series with the power supply channel, thereby reducing the power consumption and heat of the power supply channel.

[0060] Specifically, if R N1 Characterizes the impedance generated by the first field effect tube, R sense Characterizes the impedance of the current-sense resistor, R load Characterize the impedance of the load, then: In some existing technologies, without considering other field effect tubes and devices, the impedance of the power supply channel can be characterized as: R N1 +R sense+R load , correspondingly, the impedance in the optional implementation of this embodiment can be sense and is reduced, thus being characterized as: R N1 +R load .

[0061] In this embodiment, the control module 11 may be connected to the gate of the first field effect transistor 21, and is used to control the first field effect transistor 21 to be turned off when the normal working current information of the power channel needs to be determined.

[0062] At the same time, the parallel branch 12 can remain conductive when the normal working current information needs to be determined. Specifically, for example, the control module 11 can also be connected to the parallel branch 12 to control the parallel branch 12 to remain conductive when the normal working current information needs to be determined. In the specific implementation process, the parallel branch 12 can remain conductive during normal operation. At the same time, this embodiment does not exclude the situation where it does not remain conductive during normal operation.

[0063] The current detection module 13 is connected to the parallel branch 12 and is used to detect the current information of the parallel branch 12 so that the normal operating current information can be determined according to the current information of the parallel branch 12 when the first field effect transistor 21 is turned off and the parallel branch 12 is turned on.

[0064] When it is necessary to detect the normal operating current information, the above implementation method can control the first field effect tube to be turned off through the control module, and the parallel branch can remain turned on, and the current enters the load through the parallel branch. At this time, the current information of the parallel branch can be associated with the normal operating current information during normal operation (that is, when the first field effect tube and the parallel branch are both turned on). Furthermore, the normal operating current information can be determined based on the current information when the parallel branch is turned on alone.

[0065] This embodiment realizes effective detection of the current of the power channel based on the parallel branch, the current detection module and the control module. While realizing effective detection, it can reduce the power consumption and heat of the power channel by avoiding connecting the current detection resistor in series with the power channel.

[0066] It can be seen that the above implementation method can use the time-sharing method to detect current information, that is, the circuit state during detection can be different from that during non-detection. In the application scenario of charging or power supply of electronic devices, the current change speed is often very slow, and thus, the time-sharing measurement method will not affect the charging or power supply itself.

[0067] At the same time, since the measurement is performed in time-sharing mode, the impedance of the parallel branch does not need to be very small, thereby making it easier to balance detection accuracy and cost.

[0068] In comparison, in the existing related technologies, in order to reduce the problems of power loss and heat dissipation, a current sensing resistor with an extremely small resistance is usually selected for the series current sensing resistor, for example, it can be as small as 1 to 2 milliohms, thereby simplifying the system's heat dissipation design or improving the system's current flow capacity, thereby improving the power supply capacity or charging speed.

[0069] However, in order to match this type of extremely small current-sense resistor, current-sense amplifiers, analog-to-digital converters, etc. need to choose matching models, and such current-sense amplifiers and analog-to-digital converters will also have relatively high accuracy and may also be expensive. It can be understood that the smaller the current-sense resistor, the higher the cost of the current-sense amplifier and analog-to-digital converter that match it. At the same time, the smaller the current-sense resistor, the greater the impact of the op amp's offset voltage and input bias current, which will make it difficult to guarantee the accuracy of current measurement.

[0070] According to the description of the above implementation modes of the present embodiment, it can be seen that the impedance of the parallel branch in the present embodiment does not need to be very small, that is, the impedance can be made larger and more flexible. Since the impedance of the parallel branch does not need to be very small, on the one hand, it is convenient to obtain higher current measurement accuracy, and on the other hand, the selection range of devices in the current detection module will not be limited due to the small current detection resistance, and thus it can be suitable for using lower cost devices. It can be seen that the above implementation modes can easily take into account both detection accuracy and cost.

[0071] In one embodiment, when the impedance of the first field effect transistor and the parallel branch is small enough, for example, less than a certain threshold, its impedance can be ignored relative to the load. At this time, the current information measured when the parallel branch is turned on alone can be used as the normal working current information.

[0072] This embodiment does not exclude the implementation method of not ignoring the impedance of the first field effect transistor and the parallel branch. Since the impedance of the first field effect transistor, the parallel branch, the load and other devices are known, the voltage of the power input terminal 22 is also known. The quantitative relationship between the current information of the parallel branch when it is individually turned on and the normal working current information when both are turned on can also be calculated through circuit principles, so as to calculate the normal working current information based on the quantitative relationship.

[0073] During the specific implementation process, the first field effect transistor 21 is controlled to remain turned on most of the time (for example, 99.9% or more of the time) to achieve normal power supply, that is, after the current flows into the power input terminal 22, it can flow directly or indirectly into the load 23 through the parallel channel generated by the first field effect transistor 21 and the parallel branch 12 being connected in parallel, and finally flow back to the ground.

[0074] In a small part of the time (for example, less than 0.1% of the time), which can be understood as the time when the normal working current information needs to be obtained, when the current flows from the power input terminal 22 through the above-mentioned parallel channel and then enters the load 23, the control module 11 can first ensure that the parallel branch remains in the on state, and then turn off the first field effect tube 21, that is, turn off the original power channel 2. At this time, the current from the power input terminal 22 to the load 23 all flows through the parallel branch 12. The current detection module 13 can be used to measure the current flowing through the parallel branch 12, and the obtained current is the current flowing through the parallel channel of the first field effect tube 21 and the parallel branch 12 during normal operation.

[0075] The normal operation involved above can be understood as a circuit state in which the power supply channel 2 is turned on to use the power supply of the power input terminal 22 to supply power to the load 23 .

[0076] In one embodiment, the first field effect transistor 21 may be a field effect transistor with a smaller on-resistance, for example, smaller than the impedance generated by the parallel branch 12, that is, the impedance generated by the first field effect transistor 21 is smaller than the impedance generated by the parallel branch 12. Furthermore, when the first field effect transistor 21 and the parallel branch 12 are connected in parallel and both are turned on, that is, when working normally, the current may mainly flow through the first field effect transistor 21.

[0077] Figure 2 FIG. 1 is a schematic diagram of the structure of a power supply channel and a current detection circuit in an embodiment of the present invention. Figure 2 .

[0078] The parallel branch 12 can be understood as any branch that can generate impedance suitable for current collection and is connected in parallel to the first field effect transistor 21, and can have any device or combination of devices that can achieve the above functions.

[0079] In one implementation, please refer to Figure 2 The parallel branch 12 is provided with a second field effect transistor 121, and the second field effect transistor 121 can remain turned on. In a specific implementation process, it can remain turned on under the control of the control module 11. For example, the control module 11 is connected to the gate of the second field effect transistor 121, and is specifically used to control the second field effect transistor 121 to remain turned on when the normal working current information needs to be determined. Among them, controlling the second field effect transistor 121 to be turned on means controlling the parallel branch 12 to be turned on.

[0080] In a further specific implementation process, the control module 11 can also control the second field effect transistor 121 to remain turned on during normal operation.

[0081] The second field effect transistor 121 can provide a certain impedance and can also be controlled to be on and off, so that the parallel branch 12 can achieve the above-mentioned functions.

[0082] In other implementations, a current-sensing resistor may be used to replace the second field-effect transistor 121 .

[0083] Figure 3 FIG. 1 is a schematic diagram of the structure of a power supply channel and a current detection circuit in an embodiment of the present invention. Figure 3 .

[0084] Please refer to Figure 3 In one embodiment, the control module 11 includes a charge pump control unit 111, and an output end of the charge pump control unit 111 is connected to the gate of the first field effect transistor 21 to control the first field effect transistor 21 to be turned off when the normal working current information of the power supply channel 2 needs to be determined. The output end of the charge pump control unit 111 can be a first output end.

[0085] During the specific implementation process, another second output terminal of the charge pump control unit 111 can be connected to the parallel branch 12 to control the parallel branch 12 to remain conductive, specifically, it can remain conductive both during normal operation and when the normal operating current information of the power supply channel needs to be determined.

[0086] If the charge pump control unit 111 needs to use two output terminals externally, in one example, the charge pump control unit 111 can be a charge pump control unit with two output terminals, and the two output terminals can output different signals; in another example, the charge pump control unit 111 can have two charge pumps, each using one output terminal to output a signal.

[0087] The charge pump control unit mentioned above can also be characterized as Charge Pump Ctrl, where Ctrl can be understood as Controller. Its conventional function can also be understood as: a circuit unit used to drive (i.e. manage) the on and off of the field effect tube involved in this embodiment inside the chip. However, this embodiment can further enable it to control the on and off of the field effect tube outside the chip, which can be understood by referring to the relevant description below.

[0088] In one embodiment, the current detection module is further connected to a data processing module, and the data processing module is used to obtain the current information of the parallel branch when the first field effect transistor is turned off and the parallel branch is turned on, and determine the normal working current information according to the current information. For example, the current information of the parallel branch at this time can be determined as the normal working current information.

[0089] In one implementation manner, the data processing module may be an existing module in the electronic device, or may be an additionally configured module.

[0090] Figure 4FIG. 1 is a schematic diagram of the structure of a power supply channel and a current detection circuit in an embodiment of the present invention. Figure 4 .

[0091] Please refer to Figure 4 In one embodiment, the control module 11 is also connected to the gate of a third field effect transistor 24 , and the third field effect transistor 24 is disposed in the power supply channel 2 and between the first field effect transistor 21 and the load 23 .

[0092] The on-off of the third field effect tube 24 can be consistent with the on-off of the parallel branch 12. Furthermore, in the specific implementation process, the third field effect tube 24 and the parallel branch 12 can be connected to the same output end of the charge pump control unit 111. At the same time, this embodiment does not exclude the solution of connecting the third field effect tube 24 and the parallel branch 12 to different output ends respectively.

[0093] In one implementation, please refer to Figures 1 to 4 As mentioned above, the control module 11 is also connected to the parallel branch 12 for:

[0094] The parallel branch 12 is controlled to remain conducting both during normal operation and when the normal operating current information needs to be determined.

[0095] During the specific implementation process, the control module 11 can also be used to:

[0096] When the voltage at the power input terminal 22 is over-voltage or under-voltage, the parallel branch 12 is controlled to be turned off, thereby protecting the circuit.

[0097] The current detection module 13 mentioned above can be understood as any device or combination of devices that can detect the current of the parallel branch 12, which can be connected in parallel to both ends of the parallel branch. The current detection module 13 can be specifically characterized as: CurrentMeasure.

[0098] In an example, the current detection module 13 may include a current detection amplifier CSA and an analog-to-digital converter ADC. The current detection amplifier CSA may be connected in parallel to the parallel branch and connected to the analog-to-digital converter ADC.

[0099] In another example, the current detection module 13 may support a mirror current mode, thereby improving the accuracy and consistency of the main current measurement.

[0100] Among them, if a second field effect transistor 121 is provided in the parallel branch 12, then: the current detection module 13 may include a mirror field effect transistor ADC that is proportional to the size of the second field effect transistor 121, and an analog-to-digital converter, wherein the second field effect transistor 121 and the mirror field effect transistor can be in a highly accurate proportional relationship to obtain the required mirror current, the mirror field effect transistor is connected in series with the configured resistor, and the end of the resistor that is not connected to the mirror field effect transistor can be grounded, and the analog-to-digital converter ADC can collect the voltage drop of the resistor for characterizing the current information, for example: the voltage drop on the resistor can be directly connected to the input of the analog-to-digital converter.

[0101] Furthermore, the current obtained by the mirroring of the mirror field effect transistor can be in precise proportional relationship with the current of the second field effect transistor 121, and the analog-to-digital converter can collect the current information of the second field effect transistor 121.

[0102] The analog-to-digital converter involved in the above example can be connected to the data processing module involved above or other devices or combinations of devices for obtaining current information, so that it can determine the current information of the second field effect transistor 121, wherein it can be determined that the current information of the second field effect transistor 121 when the first field effect transistor 21 is turned off is the normal operating current information.

[0103] Based on the above-mentioned scheme, after using the mirror current and its corresponding configurable resistor, the impedance of the parallel circuit and the current detection module generated by the current detection can be amplified by, for example, 1000 times relative to the current detection resistor in the prior art. The prior art amplifies the voltage drop on the original current detection resistor by a fixed multiple (for example, 50 times) through the current detection amplifier CSA and then enters the analog-to-digital converter ADC for measurement. The present embodiment can control the selection of different resistors for measurement. For example, when the current to be measured is very small, a current detection resistor that is amplified by 1000×50 times relative to the resistor in the prior art is used. When the current to be measured is large, a resistor that is amplified by 1000 times is continued to be used.

[0104] In one implementation, please refer to Figures 1 to 4 As mentioned above, the control module 11 can also be used to control the first field effect transistor 21 to be turned on during normal operation.

[0105] In the specific implementation process, the parallel branch 12, the current detection module 13 and the control module 11 involved above can be integrated into the same chip. The chip can be understood as a control chip, which can be specifically characterized as: App Specific Ctrl, where Ctrl can be understood as Controller.

[0106] The data processing modules mentioned above may be arranged on the same chip or may not be arranged on the same chip.

[0107] If the parallel branch 12, the current detection module 13 and the control module 11 are integrated into the same chip, the charge pump control unit 111 in the control module 11 can not only control the on and off of the second field effect transistor 121 inside the chip, but also lead out a control pin to control the on and off of external field effect transistors (such as the first field effect transistor 21 and the third field effect transistor 24), that is: the charge pump control unit in the control module is connected to the first field effect transistor and / or the third field effect transistor through the pin of the control chip. In comparison, when the charge pump output control is adopted in the existing related technology, it is usually output to the internal devices of the chip. Therefore, the above implementation method can further enrich the diversity of the output function of the charge pump control unit and is no longer limited to the chip.

[0108] In addition, in the existing related technologies, a smaller current sensing resistor will also cause a larger relative error during the welding process, and even affect the consistency of the current detection results of batch products. In comparison, when the above implementation schemes are adopted, since there is no need to weld a smaller current sensing resistor, it is also easier to reduce the error and improve the consistency of the detection results.

[0109] Figure 5 Schematic diagram of a power supply channel and a current detection circuit in one embodiment of the present invention.

[0110] Please refer to Figure 5 , and combined with Figures 1 to 4 , wherein the first field effect tube 21, the second field effect tube 121 and the third field effect tube 24 involved can all be N-type field effect tubes. 1 To characterize, the second field effect tube 121 can be N 2 To characterize, the third field effect tube 24 can be N 3 To characterize, the load 23 can be represented by R load To represent, the power input terminal 22 may be VIN.

[0111] Furthermore, R N1 To characterize the impedance of the first field effect tube 21, R N2 Characterizes the impedance of the second field effect tube 121, R N3 Characterizes the impedance of the third field effect transistor 24.

[0112] In a specific implementation process, for example, 99.9% or more of the time, the first field effect transistor N 1 Keep it turned on to achieve normal operation, wherein the current starts from the power input terminal VIN and flows through the first field effect transistor N 1 With the second field effect transistor N 2 The parallel channel and the third field effect tube N 3 Inflow load R loadAfter that, it flows back to the ground GND. For example, in the time less than 0.1%, it is necessary to know that at this time, the power input terminal VIN flows through the first field effect transistor N 1 and the second field effect transistor N 2 The parallel channel is then connected by the third field effect transistor N 3 Enter the load R load When the current is high, the charge pump control unit (i.e. Charge Pump Ctrl) of the control chip (i.e. App Specific Ctrl) involved above first ensures that the second field effect transistor N 2 Still keep conducting, then turn off the first field effect tube N 1 channel, at this time the power input terminal VIN to the load R load All the current flows through the second field effect transistor N 2 The current detection module (i.e., Current Measure) of the control chip (i.e., App Specific Ctrl) can detect the current flowing through the second field effect transistor N 2 The current obtained is the current flowing through the first field effect transistor N during normal operation. 1 and the second field effect transistor N 2 The current of the parallel channel is measured. Since the detection current method of parallel connection is adopted but the external path of the control chip is turned off during measurement, the on-resistance of the key main current path (i.e., the power supply channel) is reduced. The on-resistance is reduced by R N1 +R N3 +Rsense becomes R in the specific implementation process N1 +R N3 , reducing the power loss and heat generation of the path during normal power supply or charging operation.

[0113] In addition, the mode of integrating control and detection into the control chip (ie, App Specific Ctrl) also optimizes system cost, reduces circuit area, and improves the accuracy and consistency of current detection.

[0114] This embodiment further provides an electronic device, including the current detection circuit and the power supply channel involved in the above optional solutions.

[0115] To summarize, in the current detection circuit and electronic device of the power supply channel provided in this embodiment, the current detection resistor is avoided to be connected in series with the power supply channel, and a parallel branch connected in parallel with the first field effect tube is adopted. When the normal working current information needs to be detected, this embodiment can control the first field effect tube to be turned off through the control module, and the parallel branch can remain turned on, and the current enters the load through the parallel branch. At this time, the current information of the parallel branch can be associated with the normal working current information during normal operation (that is, when the first field effect tube and the parallel branch are both turned on). Furthermore, the normal working current information can be determined based on the current information when the parallel branch is turned on alone. For example, when the impedance of the first field effect tube and the parallel branch is small enough, it can be ignored relative to the load. At this time, the current information measured when the parallel branch is turned on alone can be used as the normal working current information.

[0116] This embodiment realizes effective detection of the current of the power channel based on the parallel branch, the current detection module and the control module. While realizing effective detection, it can avoid connecting a current detection resistor in series with the power channel, thereby reducing the power consumption and heat of the power channel.

[0117] At the same time, since the impedance of the parallel branch does not need to be very small, on the one hand, it is easy to obtain higher current measurement accuracy, and on the other hand, the selection range of devices in the current detection module will not be limited due to the small current detection resistance, and thus it can be suitable for using lower cost devices. It can be seen that this embodiment can also facilitate taking into account both detection accuracy and cost.

[0118] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A current detection circuit for a power supply channel, wherein the power supply channel comprises a power supply input terminal, a first field effect transistor and a load connected in sequence, characterized in that: The current detection circuit comprises: a parallel branch, a current detection module and a control module; the parallel branch is connected in parallel to the two ends of the first field effect tube; The control module is connected to the gate of the first field effect transistor, and is used to control the first field effect transistor to be turned off when the normal working current information of the power supply channel needs to be determined; The parallel branch can remain conductive when the normal operating current information needs to be determined; The current detection module is connected to the parallel branch and is used to detect the current information of the parallel branch, so that the normal working current information can be determined according to the current information of the parallel branch when the first field effect transistor is turned off and the parallel branch is turned on; The parallel branch, the current detection module and the control module are integrated into the same control chip.

2. The current detection circuit according to claim 1, characterized in that: A second field effect transistor is provided in the parallel branch, and the second field effect transistor can remain turned on when the normal working current information needs to be determined.

3. The current detection circuit according to claim 2, characterized in that: The current detection module includes a mirror field effect transistor that is proportional to the size of the second field effect transistor, and an analog-to-digital converter. The mirror field effect transistor is connected in series with a configured resistor, and one end of the resistor that is not connected to the mirror field effect transistor is grounded. The analog-to-digital converter can collect a voltage drop of the resistor for characterizing current information.

4. The current detection circuit according to claim 1, characterized in that: The impedance generated by the first field effect transistor is smaller than the impedance generated by the parallel branch.

5. The current detection circuit according to claim 1, characterized in that: The control module includes a charge pump control unit, and an output end of the charge pump control unit is connected to the gate of the first field effect transistor to control the first field effect transistor to be turned off when the normal working current information of the power supply channel needs to be determined.

6. The current detection circuit according to any one of claims 1 to 5, characterized in that: The current detection module is also connected to a data processing module, and the data processing module is used to obtain the current information of the parallel branch when the first field effect transistor is turned off and the parallel branch is turned on, and determine the normal working current information according to the current information.

7. The current detection circuit according to any one of claims 1 to 5, characterized in that: The control module is also connected to the gate of a third field effect transistor, and the third field effect transistor is arranged in the power supply channel and between the first field effect transistor and the load.

8. The current detection circuit according to any one of claims 1 to 5, characterized in that: The control module is also connected to the parallel branch for: Controlling the parallel branch to remain on both in normal operation and when the normal operating current information needs to be determined, and / or: controlling the parallel branch to be turned off when the voltage at the power input end is over-voltage or under-voltage; The control module is also used to control the first field effect transistor to be turned on during normal operation.

9. An electronic device, characterized in that: It comprises the current detection circuit and power supply channel as described in any one of claims 1 to 8.

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