CN210487852U - Current detection circuit of power channel and electronic equipment - Google Patents
Current detection circuit of power channel and electronic equipment Download PDFInfo
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- CN210487852U CN210487852U CN201921327254.9U CN201921327254U CN210487852U CN 210487852 U CN210487852 U CN 210487852U CN 201921327254 U CN201921327254 U CN 201921327254U CN 210487852 U CN210487852 U CN 210487852U
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Abstract
The utility model provides a power supply channel's current detection circuit and electronic equipment, current detection circuit includes: the parallel branch, the current detection module and the control module are connected in parallel; the parallel branch is connected in parallel with two ends of the first field effect transistor; the control module is connected with the grid electrode of the first field effect transistor and is used for controlling 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 circuit can be kept conducted when the normal working current information needs to be determined; the current detection module is connected with the parallel branch and used for detecting 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 switched off and the parallel branch is switched on. The utility model discloses when realizing effectively detecting, thereby can avoid reducing power supply channel's consumption and heat at power supply channel series current detection resistance.
Description
Technical Field
The utility model relates to a chargeable electronic equipment especially relates to a charging circuit's current detection circuit and electronic equipment.
Background
In an electronic device, a load may be powered through a power channel, wherein a current path of the power channel may be managed by a circuit device, for example, in a mobile phone, a direct charging path management may be implemented through a related circuit device.
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 channel, a current detection resistor is usually required to be arranged in the power channel, and the current detection resistor is connected in series with the load, so that the current information of the current detection resistor can be sampled by a current detection amplifier to obtain a voltage signal for representing the current information, the voltage signal is amplified, and the amplified signal is subjected to analog-to-digital conversion by an analog-to-digital converter so as to be acquired by the logic control module.
In the process, because the load needs to be connected in series with the current detection resistor, the impedance of the power channel is large, power loss is easily caused by the current detection resistor, and heat dissipation of the power channel is increased due to power consumption of the current detection resistor.
SUMMERY OF THE UTILITY MODEL
The utility model provides a power supply channel's current detection circuit and electronic equipment to produced problem when solving and utilizing to examine current resistance detection power supply channel.
According to the utility model discloses an aspect provides a power supply channel's current detection circuit, power supply channel is including the power input end, first field effect transistor and the load that connect gradually, current detection circuit includes: the parallel branch, the current detection module and the control module are connected in parallel; the parallel branch is connected in parallel with two ends of the first field effect transistor;
the control module is connected with the grid electrode of the first field effect transistor and is used for controlling 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 circuit can be kept conducted when the normal working current information needs to be determined;
the current detection module is connected with the parallel branch and used for detecting 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 switched off and the parallel branch is switched on.
Optionally, a second field effect transistor is arranged in the parallel branch, and the second field effect transistor can be kept on when the normal working current information needs to be determined.
Optionally, the current detection module includes a mirror field effect transistor in a proportional relationship with a size of the second field effect transistor, and an analog-to-digital converter, the mirror field effect transistor is connected in series with the configured resistor, one end of the resistor, which is not connected to the mirror field effect transistor, is grounded, and the analog-to-digital converter can acquire a voltage drop of the resistor for representing current information.
Optionally, the impedance generated by the first field effect transistor is smaller than the impedance generated by the parallel branch.
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, so as 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.
Optionally, the current detection module is further connected to a data processing module, and the data processing module is configured 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 according to the current information.
Optionally, the control module is further connected to a gate of a third field effect transistor, and the third field effect transistor is disposed in the power channel and between the first field effect transistor and the load.
Optionally, the control module is further connected to the parallel branch, and configured to:
and controlling the parallel branch to be kept conducted when the parallel branch works normally and the normal working current information needs to be determined.
Optionally, the control module is further connected to the parallel branch, and configured to:
and controlling the parallel branch to be switched off when the voltage at the power input end is in overvoltage or undervoltage.
Optionally, the control module is further configured to: and when the device works normally, the first field effect tube is controlled to be conducted.
According to a second aspect of the present invention, there is provided an electronic device comprising the current detection circuit and the power supply channel related to the first aspect and the alternative thereof.
The current detection circuit and the electronic equipment of the power channel provided by the utility model avoid the series connection of the current detection resistor in the power channel, and adopt the parallel branch circuit connected with the first field effect tube in parallel, when the normal working current information needs to be detected, the utility model can control the first field effect tube to be turned off through the control module, and the parallel branch can be kept conducted, the current enters the load through the parallel branch, at the moment, the current information of the parallel branch can be related to the normal working current information when the parallel branch works normally (namely, when the first field effect transistor and the parallel branch are both conducted), further, the normal operating current information may be determined based on current information when the parallel branches are individually turned on, for example, when the impedances of the first fet and the parallel branches are sufficiently small, the current information measured when the parallel branch is independently conducted can be used as the normal working current information.
The utility model discloses based on parallelly connected branch road, current detection module and control module, realized effectively detecting the power supply channel electric current, when realizing effectively detecting, thereby can avoid reducing power supply channel's consumption and heat at power supply channel series current detection resistance.
Simultaneously, because the impedance of parallelly connected branch road can not need very little, can be convenient for obtain the measurement accuracy of higher electric current on the one hand, the lectotype scope of device can not be restricted because of examining the electric resistance undersize in the on the other hand current detection module, and then can be suitable for and use lower cost's device, it is visible, the utility model discloses still can be convenient for compromise simultaneously and detect precision and cost.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without inventive exercise.
Fig. 1 is a first schematic structural diagram of a power channel and a current detection circuit according to an embodiment of the present invention;
fig. 2 is a schematic structural diagram of a power channel and a current detection circuit according to an embodiment of the present invention;
fig. 3 is a third schematic diagram illustrating a structure of a power channel and a current detection circuit according to an embodiment of the present invention;
fig. 4 is a fourth schematic structural diagram of the power channel and the current detection circuit according to an embodiment of the present invention;
fig. 5 is a schematic circuit diagram of a power channel and a current detection circuit according to an embodiment of the present invention.
Description of reference numerals:
1-a current detection circuit;
11-a control module;
111-a charge pump control unit;
12-parallel branch;
121、N2-a second field effect transistor;
13-a current detection module;
2-power channel;
21、N1-a first field effect transistor;
22. VIN-power input terminal;
23、Rload-a load;
24、N3-a third field effect transistor;
a CSA-current sense amplifier;
ADC-analog-to-digital converter.
Detailed Description
The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.
The terms "first," "second," "third," "fourth," and the like in the description and in the claims, as well as in the drawings, if any, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the invention described herein are capable of operation in sequences other than those illustrated or otherwise described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.
The technical solution of the present invention will be described in detail with specific examples. The following several specific embodiments may be combined with each other, and details of the same or similar concepts or processes may not be repeated in some embodiments.
Fig. 1 is a first schematic structural diagram of a power channel and a current detection circuit according to an embodiment of the present invention.
Referring to fig. 1, a current detection circuit of a power channel is provided, where the power channel 2 includes a power input terminal 22, a first fet 21, and a load 23, which are connected in sequence.
The power channel 2 can be understood as any circuit configuration capable of supplying power from the power input terminal 22 to the load 23, wherein the first fet 21 can be configured to control the connection/disconnection between the power input terminal 22 and the load 23. Meanwhile, this embodiment does not exclude the solution that the power channel 2 is further provided with at least one device of another switch, a resistor, etc., wherein the switch may be another fet, for example.
In practical use, in some scenarios, the current of the power channel 2 may need to be detected, and the following description will be given by taking a mobile phone as an example of an electronic device:
in the direct charging path management of the mobile phone, the current path often needs to be controlled to be turned on and off, and even needs to support a bidirectional turn-off and a specified unidirectional turn-on function, a device performing the function may be, for example, the above first fet 21 and/or the below-mentioned third fet 24, meanwhile, the power channel 2 may refer to the above-mentioned current path, and further, in some scenarios, the speed of power supply, charging, and heating may be optimized through the management of the power channel 2 (for example, on-off control of the first fet 21). Therefore, in order to manage charging or power supply safety, adjust charging speed, know the power transmission condition, and the like, the current of the power channel 2 needs to be detected.
In view of this, in the related art, the control of the fet in the power channel 2 and the detection of the current information are implemented by different devices, respectively.
The number of power channels 2 in the electronic device may be one, while embodiments in which the number of power channels 2 is more than one are not excluded. Correspondingly, the same current detection circuit can be used for detection, and different current detection circuits can also be used for detection.
The first field effect transistor 21 may be any field effect transistor.
The load 23 is understood to be any device or collection of devices in an electronic apparatus to be supplied with electric energy, and in a specific implementation, the load 23 may include, for example, a consumer device module and/or an energy storage module. The end of the load 23 remote from the first fet 21 may be directly or indirectly connected to ground.
The power input 22 can be understood as any circuit node capable of supplying power to a load, and the front end of the power input can be connected with an external power supply interface of an electronic device, an energy storage device, and any other device or equipment capable of supplying power to the power input.
In this embodiment, the current detection circuit 1 includes: the device comprises a parallel branch 12, a current detection module 13 and a control module 11, wherein the parallel branch 12 is connected in parallel with two ends of the first field effect transistor 21.
Therefore, the above embodiment can avoid the series connection of the current detection resistors in the power channel, thereby reducing the power consumption and heat of the power channel.
In particular, if R isN1Characterizing the impedance, R, produced by the first field effect transistorsenseCharacterizing the impedance of the current-sensing resistor, RloadCharacterizing the impedance of the load, then: in some prior art, the impedance of the power channel can be characterized without considering other fets and devices as follows: rN1+Rsense+RloadCorrespondingly, the impedance in the alternative embodiment of this embodiment may be due to no RsenseBut decreases and is thus characterized as: rN1+Rload。
In this embodiment, the control module 11 may be connected to a gate of the first fet 21, and is configured to control the first fet 21 to turn off when the normal operating current information of the power channel needs to be determined.
Meanwhile, the parallel branch 12 may be kept on when the normal operating current information needs to be determined, and specifically, for example: the control module 11 may also be connected to the parallel branch 12, and configured to control the parallel branch 12 to remain on when the normal operating current information needs to be determined. In a specific implementation process, the parallel branch 12 may also be kept in conduction during normal operation, and meanwhile, this embodiment does not exclude the situation that the parallel branch is not kept in conduction during normal operation.
The current detection module 13 is connected to the parallel branch 12 and configured to detect 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 fet 21 is turned off and the parallel branch 12 is turned on.
When normal working current information needs to be detected, the first field effect transistor can be controlled to be switched off through the control module in the above embodiment, the parallel branch can be kept switched on, current enters the load through the parallel branch, the current information of the parallel branch can be associated with the normal working current information during normal working (namely when the first field effect transistor and the parallel branch are both switched on), and then the normal working current information can be determined according to the current information during independent switching on of the parallel branch.
The embodiment is based on the parallel branch, the current detection module and the control module, realizes effective detection of the current of the power supply channel, and can reduce the power consumption and heat of the power supply channel due to the fact that the current detection resistor is prevented from being connected in series with the power supply channel while the effective detection is realized.
As can be seen, in the above embodiment, the current information can be detected in a time-sharing manner, that is: the state of the circuit at the time of detection may be different from that at the time of non-detection. In the application scene of charging or power supply, the current change speed of the electronic equipment is very slow, and further, the time-sharing measurement mode cannot influence the charging or power supply.
Meanwhile, the impedance of the parallel branch can be measured in a time-sharing manner without being very small, so that the detection precision and the cost are convenient to take into account.
In contrast, in the related art, for the current detection resistors connected in series, in order to reduce the power loss and the heat dissipation problem, the current detection resistor with a very small resistance value, for example, as small as 1 to 2 milliohms, is usually selected, so as to simplify the heat dissipation design of the system or improve the current capacity of the system, and improve the power supply capacity or the charging speed.
However, in order to match such a very small current detection resistor, the current detection amplifier, the analog-to-digital converter, and the like need to select a model matched with the current detection amplifier, and such a current detection amplifier and an analog-to-digital converter also have relatively high precision and may have high cost, which is understood that the smaller the current detection resistor, the higher the cost of the current detection amplifier and the analog-to-digital converter matched with the current detection amplifier is. Meanwhile, the smaller the current detection resistance is, the larger the influence of the offset voltage and the input bias current of the operational amplifier is, which may cause difficulty in ensuring the measurement accuracy of the current.
As can be seen from the above description of the embodiments of the present embodiment, the impedance of the parallel branch in the present embodiment may not need to be very small, that is: the impedance can be made to be larger and more flexible, because the impedance of the parallel branch can be not needed to be very small, on one hand, the measurement precision of the higher current can be conveniently obtained, on the other hand, the model selection range of the device in the current detection module can not be limited due to the undersize of the current detection resistor, and then the current detection module can be suitable for using the device with lower cost, and therefore, the above implementation mode can be convenient for considering both the detection precision and the cost.
In one embodiment, when the impedance of the first fet and the parallel branch is sufficiently small, for example, smaller than a certain threshold, the impedance thereof can be ignored with respect to the load, and at this time, the measured current information when the parallel branch is turned on alone can be used as the normal operating current information.
This embodiment does not exclude the implementation that does not ignore the impedances of the first fet and the parallel branch, because the impedances of the first fet, the parallel branch, the load, and the like are known, and the voltage at the power input terminal 22 is also known, and the quantization relationship between the current information of the parallel branch when the first fet is separately turned on and the normal operating current information when the first fet is all turned on can also be calculated by the circuit principle, so that the normal operating current information is calculated according to the quantization relationship.
In the specific implementation process, the first fet 21 is controlled to remain 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 from the power input terminal 22, the current can directly or indirectly flow into the load 23 via the parallel channel generated by the first fet 21 in parallel with the parallel branch 12, and finally flows back to the ground.
In a small portion of time (for example, less than 0.1%), it can be understood that the time when the normal operating current information needs to be obtained, at this time, when the current from the power input terminal 22 flows through the above-mentioned parallel channel and then enters the load 23, the control module 11 may first ensure that the parallel branch still maintains the conducting state, and then turn off the first fet 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, and the current flowing through the parallel branch 12 may be measured by the current detection module 13, and the obtained current is the current flowing through the parallel channel of the first fet 21 and the parallel branch 12 during normal operation.
The normal operation referred to above is understood to be a circuit state in which the power channel 2 is conducting to supply the load 23 with power from the power input 22.
In one embodiment, the first fet 21 may be a fet with a relatively small on-resistance, for example, smaller than the impedance generated by the parallel branch 12, that is: the impedance generated by the first fet 21 is less than the impedance generated by the parallel branch 12. Furthermore, when the first fet 21 and the parallel branch 12 are connected in parallel and are both turned on, i.e. in normal operation, current can mainly flow through the first fet 21.
Fig. 2 is a schematic structural diagram of a power channel and a current detection circuit according to an embodiment of the present invention.
The parallel branch 12 can be understood as any branch capable of generating impedance suitable for being current-collected and connected in parallel to the first fet 21, and can have any device or combination of devices capable of achieving the above functions.
In one embodiment, referring to fig. 2, a second fet 121 is disposed in the parallel branch 12, and the second fet 121 can be kept on, and in a specific implementation process, the second fet 121 can be kept 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 configured to control the second field effect transistor 121 to keep conducting when the normal operating current information needs to be determined. Wherein, the second fet 121 is controlled to be turned on, i.e. the parallel branch 12 is controlled to be turned on.
In a further specific implementation process, the control module 11 may further control the second fet 121 to remain on during a normal operation.
The second fet 121 can provide a certain impedance and can be controlled to be turned on or off, so that the parallel branch 12 can achieve the above-mentioned functions.
In other embodiments, a current-detecting resistor may be used instead of the second fet 121.
Fig. 3 is a third schematic diagram of the structure of the power channel and the current detection circuit according to an embodiment of the present invention.
Referring to fig. 3, in an embodiment, the control module 11 includes a charge pump control unit 111, an output terminal of the charge pump control unit 111 is connected to the gate of the first fet 21, so as to control the first fet 21 to turn off when the normal operating current information of the power channel 2 needs to be determined, and the output terminal of the charge pump control unit 111 may be a first output terminal.
In a specific implementation process, the other second output terminal of the charge pump control unit 111 may be connected to the parallel branch 12 to control the parallel branch 12 to be kept on, and specifically, the parallel branch 12 may be kept on during normal operation and when the normal operation current information of the power channel needs to be determined.
If the charge pump control unit 111 needs to use two output terminals externally, for example, the charge pump control unit 111 may be a charge pump control unit having two output terminals, and the two output terminals can output different signals; for another example, the charge pump control unit 111 may have two charge pumps, each outputting a signal via one output terminal.
The charge pump control unit referred to above may also be characterized as: charge Pump Ctrl, where Ctrl may be understood as Controller. Its conventional role can also be understood as: and a circuit unit for respectively driving (i.e. managing) on and off the field effect transistor according to the embodiment in the chip. However, the present embodiment further enables off-chip fet on-off control, which can be understood with reference to the related description below.
In one embodiment, the current detection module is further connected to a data processing module, and the data processing module is configured to obtain current information of the parallel branch when the first fet is turned off and the parallel branch is turned on, and determine the normal operating 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 operating current information.
In one embodiment, the data processing module may be an existing module in the electronic device, or may be a module configured separately.
Fig. 4 is a fourth schematic diagram of the power channel and the current detection circuit according to an embodiment of the present invention.
Referring to fig. 4, in one embodiment, the control module 11 is further connected to a gate of a third fet 24, and the third fet 24 is disposed in the power channel 2 and between the first fet 21 and the load 23.
The on/off of the third fet 24 and the on/off of the parallel branch 12 can be kept consistent, and further, in the implementation process, the third fet 24 and the parallel branch 12 can be connected to the same output terminal of the charge pump control unit 111. Meanwhile, the present embodiment does not exclude the scheme of connecting different output terminals to the third fet 24 and the parallel branch 12, respectively.
In one embodiment, please refer to fig. 1 to 4, as mentioned above, the control module 11 is further connected to the parallel branch 12 for:
and controlling the parallel branch 12 to be kept conducted during normal work and when the normal work current information needs to be determined.
In a specific implementation process, the control module 11 may further be configured to:
when the voltage of the power input end 22 is over-voltage or under-voltage, the parallel branch 12 is controlled to be turned off. Thereby protecting the circuit.
The current detection module 13 referred to above can be understood as any device or combination of devices capable of detecting the current of the parallel branch 12, which can be connected in parallel to the two ends of the parallel branch. The current detection module 13 may be characterized in particular as: CurrentMeasure.
In one example, the current detection module 13 may include a current detection amplifier CSA and an analog-to-digital converter ADC, and the current detection amplifier CSA may be connected in parallel to the parallel branch and connected to the analog-to-digital converter ADC.
In another example, the current detection module 13 may support a mirror current mode, so as to improve the accuracy and consistency of the measurement of the main current.
If the parallel branch 12 is provided with the second fet 121, then: the current detection module 13 may include a mirror fet ADC in proportional relation to the size of the second fet 121, and an analog-to-digital converter, where the second fet 121 and the mirror fet may be in highly precise proportional relation to obtain a required mirror current, the mirror fet is connected in series with a configured resistor, one end of the resistor, which is not connected to the mirror fet, may be grounded, and the analog-to-digital converter ADC may collect a voltage drop of the resistor for representing current information, for example: the voltage drop across the resistor may be directly connected to the input of the analog-to-digital converter.
Furthermore, the current obtained by mirroring the field effect transistor can be in an accurate proportional relationship with the current of the second field effect transistor 121, and the analog-to-digital converter can acquire the current information of the second field effect transistor 121, so as to further improve the accuracy of the current information.
The analog-to-digital converter referred to in the above example may be connected to the above-mentioned data processing module or other device or combination of devices for obtaining current information, so that it can determine the current information of the second fet 121, wherein the current information of the second fet 121 when the first fet 21 is turned off can be determined as normal operating current information.
Based on the above-mentioned solution, after the mirror current and its corresponding configurable resistance are used, the impedance of the parallel circuit and the current detection module generated by the mirror current for current detection can be amplified by, for example, 1000 times compared with the current detection resistance in the prior art, the prior art amplifies the voltage drop on the original current detection resistance 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, this embodiment can control and select different resistances for measurement, for example, the current detection resistance amplified by 1000 × 50 times compared with the resistance in the prior art is used when the current to be measured is small, and the resistance amplified by 1000 times is continued when the current to be measured is large.
In one embodiment, please refer to fig. 1 to 4, as mentioned above, the control module 11 is further configured to: and when the device works normally, the first field effect transistor 21 is controlled to be conducted.
In a specific implementation process, the parallel branch 12, the current detection module 13 and the control module 11 may be integrated on the same chip. The chip can be understood as a control chip, and can be characterized in particular as follows: app Specific Ctrl, where Ctrl is understood to be Controller.
The data processing modules may be provided on the same chip or may not be provided on the same chip.
If the parallel branch 12, the current detection module 13 and the control module 11 are integrated on the same chip, the charge pump control unit 111 in the control module 11 can lead out a control pin to control the on/off of the external fets (such as the first fet 21 and the third fet 24) in addition to controlling the on/off of the second fet 121 inside the chip, that is: the charge pump control unit in the control module is connected with the first field effect transistor and/or the third field effect transistor through the pin of the control chip, compared with the prior art that the output control of the charge pump is adopted and is usually output to the internal device of the chip, therefore, the implementation mode can further enrich the diversity of the output function of the charge pump control unit and is not limited in the chip.
In addition, in the related art, a small current detection resistor causes a large relative error in the welding process, and even influences the consistency of the current detection results of batch products. Compared with the prior art, when the scheme of each embodiment is adopted, the smaller current detection resistor does not need to be welded, so that the error can be further reduced, and the consistency of the detection result is improved.
Fig. 5 is a schematic circuit diagram of a power channel and a current detection circuit according to an embodiment of the present invention.
Referring to fig. 5 in conjunction with fig. 1 to 4, the first fet 21, the second fet 121, and the third fet 24 may be N-type fets. Thus, the first FET 21 can pass through N1Wherein the second FET 121 can be characterized by N2To characterize, the third FET 24 can be characterized by N3To characterize, the load 23 can be characterized by RloadTo characterize, the power input 22 mayIs VIN.
Further, R can be usedN1To characterize the impedance, R, of the first field effect transistor 21N2Characterizing the impedance, R, of the second field effect transistor 121N3The impedance of the third field effect transistor 24 is characterized.
In one embodiment, the first FET N is used for 99.9% or more of the time1Keeping on to realize normal operation, wherein the current starts from the power input end VIN and passes through the first field effect transistor N1And a second field effect transistor N2And the third field effect transistor N3Inflow load RloadThen flows back to ground GND, which is known to flow from the power input VIN through the first FET N in less than 0.1% of the time1And a second field effect transistor N2The parallel channel is formed by a third field effect transistor N3Into the load RloadThe Charge Pump control unit (i.e. Charge Pump Ctrl) of the above-mentioned control chip (i.e. AppSpecific Ctrl) first ensures the second fet N2Still remains on and then turns off the first field effect transistor N1When the power supply input terminal VIN reaches the load RloadAll the current of (2) flows through the second field effect transistor N2The Current detection module (i.e. Current measurement) of the control chip (i.e. App Specific Ctrl) can be coupled to the Current flowing through the second field effect transistor N2Is detected. The obtained current is the current flowing through the first field effect transistor N in normal work1And a second field effect transistor N2The current of the parallel channel of (1). The method for detecting the current of one path outside the control chip in parallel connection and switching off during measurement is adopted, so that the on-resistance of a key main current path (namely a power supply channel) is reduced, and the on-resistance is represented by R in the prior related artN1+RN3+ Rsense to R in the specific implementationN1+RN3And the power loss and the heat generation of a path during normal power supply or charging operation are reduced.
In addition, the mode of integrating the control and detection into the control chip (i.e. App Specific Ctrl) also optimizes the system cost, reduces the circuit occupation area and improves the accuracy and consistency of current detection.
The embodiment also provides an electronic device, which comprises the current detection circuit and the power supply channel related to the above options.
In summary, in the current detection circuit and the electronic device of the power channel provided in the present embodiment, the current detection resistor is not connected in series with the power channel, but a parallel branch connected in parallel with the first field effect transistor is adopted, when the normal working current information needs to be detected, the present embodiment can control the first field effect transistor to turn off through the control module, and the parallel branch can be kept conducted, the current enters the load through the parallel branch, at the moment, the current information of the parallel branch can be related to the normal working current information when the parallel branch works normally (namely, when the first field effect transistor and the parallel branch are both conducted), further, the normal operating current information may be determined based on current information when the parallel branches are individually turned on, for example, when the impedances of the first fet and the parallel branches are sufficiently small, the current information measured when the parallel branch is independently conducted can be used as the normal working current information.
The embodiment is based on the parallel branch, the current detection module and the control module, realizes effective detection of the current of the power supply channel, and can avoid reducing the power consumption and heat of the power supply channel by the series current detection resistor of the power supply channel while realizing the effective detection.
Meanwhile, the impedance of the parallel branch circuit does not need to be small, so that on one hand, higher current measurement precision can be obtained conveniently, on the other hand, the model selection range of a device in the current detection module is not limited due to the fact that the current detection resistance is too small, and therefore the current detection module can be suitable for using a device with lower cost.
Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present invention.
Claims (10)
1. The utility model provides a current detection circuit of power supply channel, power supply channel is including the power input end, first field effect transistor and the load that connect gradually, its characterized in that, current detection circuit includes: the parallel branch, the current detection module and the control module are connected in parallel; the parallel branch is connected in parallel with two ends of the first field effect transistor;
the control module is connected with the grid electrode of the first field effect transistor and is used for controlling 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 circuit can be kept conducted when the normal working current information needs to be determined;
the current detection module is connected with the parallel branch and used for detecting 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 switched off and the parallel branch is switched on.
2. The current sensing circuit of claim 1, wherein a second fet is disposed in the parallel branch, and the second fet is capable of remaining on when the normal operating current information is to be determined.
3. The current detection circuit according to claim 2, wherein the current detection module comprises a mirror field effect transistor 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, one end of the resistor, which is not connected with the mirror field effect transistor, is grounded, and the analog-to-digital converter is capable of collecting a voltage drop of the resistor for representing current information.
4. The current sensing circuit of claim 1, wherein the impedance generated by the first fet is less than the impedance generated by the parallel branch.
5. The current detection circuit according to claim 1, wherein the control module comprises a charge pump control unit, and an output terminal of the charge pump control unit is connected to the gate of the first fet to control the first fet to turn off when the normal operating current information of the power channel needs to be determined.
6. The current detection circuit according to any one of claims 1 to 5, wherein the current detection module is further connected to a data processing module, and the data processing module is configured 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 according to the current information.
7. The current sensing circuit according to any one of claims 1 to 5, wherein the control module is further connected to a gate of a third FET, and the third FET is disposed in the power channel and between the first FET and the load.
8. The current sensing circuit of any one of claims 1-5, wherein the control module is further coupled to the parallel branch for:
controlling the parallel branch to be kept on when the parallel branch works normally and the normal working current information needs to be determined, and/or: controlling the parallel branch to be switched off when the voltage at the power supply input end is over-voltage or under-voltage;
the control module is further configured to: and when the device works normally, the first field effect tube is controlled to be conducted.
9. The current detection circuit according to any one of claims 1 to 5, wherein the parallel branch, the current detection module and the control module are integrated in a same control chip.
10. An electronic device comprising the current detection circuit of any one of claims 1 to 9 and a power channel.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201921327254.9U CN210487852U (en) | 2019-08-14 | 2019-08-14 | Current detection circuit of power channel and electronic equipment |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201921327254.9U CN210487852U (en) | 2019-08-14 | 2019-08-14 | Current detection circuit of power channel and electronic equipment |
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| CN210487852U true CN210487852U (en) | 2020-05-08 |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110426549A (en) * | 2019-08-14 | 2019-11-08 | 上海爻火微电子有限公司 | The current detection circuit and electronic equipment of power channel |
| CN112260680A (en) * | 2020-10-16 | 2021-01-22 | 上海爻火微电子有限公司 | Communication circuit and electronic device |
-
2019
- 2019-08-14 CN CN201921327254.9U patent/CN210487852U/en active Active
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110426549A (en) * | 2019-08-14 | 2019-11-08 | 上海爻火微电子有限公司 | The current detection circuit and electronic equipment of power channel |
| WO2021027768A1 (en) * | 2019-08-14 | 2021-02-18 | 上海爻火微电子有限公司 | Current measurement circuit for power channel, and electronic device |
| CN112260680A (en) * | 2020-10-16 | 2021-01-22 | 上海爻火微电子有限公司 | Communication circuit and electronic device |
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