Digital closed loop current sensor

Abstract

A digital closed loop current sensor suitable for use in conjunction with a control unit. The digital closed-loop current sensor comprises a to-be-detected current conversion unit, a first signal conversion unit, a second signal conversion unit and a driving circuit. The to-be-detected current conversion unit allows to-be-detected current to flow in, and generates an analog signal and a voltage output signal through an induced magnetic field generated by the to-be-detected current. The first signal conversion unit converts an analog signal into a control signal. The second signal conversion unit receives the voltage output signal and converts the voltage output signal into a digital voltage output signal. The second signal conversion unit is electrically connected with the control unit, and the control unit receives the digital voltage output signal to obtain the magnitude of the current to be measured. The drive circuit receives the control signal and generates a reverse magnetic field in the to-be-measured current conversion unit to offset the induced magnetic field of the to-be-measured current.

Description

Technical Field

[0001] The present invention relates to a sensor, and in particular to a digital closed-loop current sensor. Background Art

[0002] Generally speaking, current sensors are used to sense the current to be measured generated by electronic devices. However, the current current sensors output analog signals, so the voltage rise and fall needs to be controlled by an external power supply device, which will increase the use of post-amplifier circuits and increase the sampling noise and delay of the signal, and will also increase the influence of electromagnetic interference on the current sensor. Therefore, how to effectively reduce the use of post-amplifier circuits and reduce the sampling noise and delay of the signal, as well as reduce the influence and loss of electromagnetic interference is an important issue at present. Summary of the invention

[0003] The present invention provides a digital closed-loop current sensor, which has no residual magnetism, fast response, reduces the influence of electromagnetic interference on the digital closed-loop current sensor and the driving power consumption, reduces the use of the post-stage amplifier circuit, and reduces the sampling noise and delay of the signal.

[0004] The present invention provides a digital closed-loop current sensor suitable for use in combination with a control unit. The digital closed-loop current sensor includes a current conversion unit to be measured, a first signal conversion unit, a second signal conversion unit and a driving circuit. The current conversion unit to be measured allows the current to flow in, and generates an analog signal and a voltage output signal through the induced magnetic field generated by the current to be measured. The first signal conversion unit is electrically connected to the current conversion unit to be measured, and converts the analog signal into a control signal. The second signal conversion unit is electrically connected to the current conversion unit to be measured, receives the voltage output signal and converts it into a digital voltage output signal, and the second signal conversion unit is electrically connected to the control unit, and the control unit receives the digital voltage output signal. The driving circuit is electrically connected to the first signal conversion unit and the current conversion unit to be measured, receives the control signal and generates a reverse magnetic field in the current conversion unit to be measured to offset the induced magnetic field of the current to be measured.

[0005] The present invention provides a digital closed-loop current sensor, comprising a current conversion unit to be measured, a first signal conversion unit, a second signal conversion unit, a control unit and a driving circuit. The current conversion unit to be measured allows the current to flow in, and generates an analog signal and a voltage output signal through the induced magnetic field generated by the current to be measured. The first signal conversion unit is electrically connected to the current conversion unit to be measured, and converts the analog signal into a digital signal. The second signal conversion unit is electrically connected to the current conversion unit to be measured, receives the voltage output signal and converts it into a digital voltage output signal. The control unit is electrically connected to the first signal conversion unit and the second signal conversion unit, receives the digital signal and the digital voltage output signal, converts the digital signal into a control signal, and outputs the digital voltage output signal. The driving circuit is electrically connected to the control unit and the current conversion unit to be measured, receives the control signal and generates a reverse magnetic field in the current conversion unit to be measured to offset the induced magnetic field of the current to be measured.

[0006] The digital closed-loop current sensor disclosed in the present invention converts the analog signal of the current conversion unit to be measured into a control signal through a first signal conversion unit, converts the voltage output signal of the current conversion unit to be measured into a digital voltage output signal to a control unit through a second signal conversion unit, and receives the control signal of the first signal conversion unit and generates a reverse magnetic field in the current conversion unit to be measured to offset the induced magnetic field of the current to be measured, or converts the analog signal of the current conversion unit to be measured into a digital signal through the first signal conversion unit, converts the voltage output signal of the current conversion unit to be measured into a digital voltage output signal through the second signal conversion unit, and the control unit converts the digital signal of the first signal conversion unit into a control signal and outputs the digital voltage output signal of the second signal conversion unit, and receives the control signal of the control unit and generates a reverse magnetic field in the current conversion unit to offset the induced magnetic field of the current to be measured. In this way, the digital closed-loop current sensor can have no residual magnetism, fast response, and can reduce the influence of electromagnetic interference and driving power consumption of the digital closed-loop current sensor, and reduce the use of the post-amplifier circuit and reduce the sampling noise and delay of the signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 is a block diagram of a digital closed-loop current sensor according to an embodiment of the present invention;

[0008] Figure 2 is a schematic diagram of the structure of a control circuit element according to an embodiment of the present invention;

[0009] Figure 3 A block diagram of a digital closed-loop current sensor according to an embodiment of the present invention.

[0010]

Explanation of symbols

[0011] 100,300: Digital closed loop current sensor

[0012] 110,310: Current conversion unit to be tested

[0013] 111: Primary side

[0014] 112: Secondary side

[0015] 113: Magnetic unit

[0016] 114: Voltage generating unit

[0017] 115: Current conductor

[0018] 116: Iron core

[0019] 117: Coil

[0020] 118: Slotting

[0021] 120,320: first signal conversion unit

[0022] 121: first impedance unit

[0023] 122: Second impedance unit

[0024] 123:Amplifier

[0025] 130,330: Second signal conversion unit

[0026] 140,350: Driving circuit

[0027] 150,340: Control unit

[0028] T1: The first transistor

[0029] T2: Second transistor

[0030] I1: Current to be measured

[0031] I2: Current

[0032] Sa: Analog signal

[0033] Sd: digital signal

[0034] Sc: control signal

[0035] Vo: voltage output signal

[0036] Vod: digital voltage output signal

[0037] V1: first reference voltage

[0038] V2: Second reference voltage DETAILED DESCRIPTION

[0039] The technical terms in this specification refer to the customary terms in the technical field. If some terms are explained or defined in this specification, the interpretation of these terms shall be based on the explanation or definition in this specification. Each embodiment of the present disclosure has one or more technical features. Under the premise of possible implementation, a person with ordinary knowledge in the technical field can selectively implement some or all of the technical features in any embodiment, or selectively combine some or all of the technical features in these embodiments.

[0040] In the various embodiments listed below, the same reference numerals will be used to represent the same or similar elements or components.

[0041] Figure 1 FIG. 4 is a block diagram of a digital closed-loop current sensor according to an embodiment of the present invention. Figure 2 FIG. 1 is a schematic diagram of a control circuit element according to an embodiment of the present invention. The digital closed-loop current sensor 100 of this embodiment is suitable for use in combination with a control unit 150. Please refer to FIG. Figure 1 and Figure 2 The digital closed-loop current sensor 100 includes a current conversion unit 110 , a first signal conversion unit 120 , a second signal conversion unit 130 and a driving circuit 140 .

[0042] The measured current conversion unit 110 can allow the measured current I1 to flow in, and generate an analog signal Sa and a voltage output signal Vo through the induced magnetic field generated by the measured current I1. In this embodiment, the analog signal Sa can be a magnetic flux signal, and is a differential signal.

[0043] The first signal conversion unit 120 can be electrically connected to the current conversion unit to be measured 110. The first signal conversion unit 120 can receive an analog signal Sa and convert the analog signal Sa into a control signal Sc. In the present embodiment, the control signal Sc can be a pulse width modulation (PWM) signal. In some embodiments, the first signal conversion unit 120 can be a proportional integral controller (PI controller) or a proportional integral derivative controller (PID controller), but the present invention is not limited thereto.

[0044] The second signal conversion unit 130 can be electrically connected to the current conversion unit 110. The second signal conversion unit 130 can receive the voltage output signal Vo and convert the voltage output signal Vo into a digital voltage output signal Vod. In some embodiments, the second signal conversion unit 130 can be an analog-to-digital converter (ADC) or a delta-sigma modulator, but the present invention is not limited thereto.

[0045] In addition, the second signal conversion unit 130 can be electrically connected to the control unit 150. The second signal conversion unit 130 can output the digital voltage output signal Vod to the control unit 150, so that the control unit 150 can receive the digital voltage output signal Vod, obtain the value of the current to be measured, and perform corresponding applications. In some embodiments, the control unit 150 can be a digital signal processor (DSP), an application specific integrated circuit (ASIC), a microcontroller (MCU), or a field programmable gate array (FPGA), but the present invention is not limited thereto.

[0046] The driving circuit 140 can be electrically connected to the first signal conversion unit 120 and the current conversion unit to be measured 110. The driving circuit 140 can receive the control signal Sc and generate a reverse magnetic field in the current conversion unit to be measured 110 to offset the induced magnetic field of the current to be measured I1. In this way, the digital closed-loop current sensor 100 can have no residual magnetism, fast response, and can reduce the influence of electromagnetic interference (EMI) and driving power consumption of the digital closed-loop current sensor 100, and reduce the use of the post-stage amplifier (OPA) circuit and reduce the sampling noise and delay of the signal.

[0047] In some embodiments, the current conversion unit 110 may include a primary side 111, a secondary side 112, a magnetic unit 113, and a voltage generating unit 114. Figure 2 As shown. The primary side 111 can be used for the waiting side current I1 to flow into and generate a magnetic field. In some embodiments, the primary side 111 may include a current conductor 115, and the waiting side current I1 flows into the current conductor 115 to generate a magnetic field.

[0048] The secondary side 112 can sense the magnetic field generated by the primary side 111 and generate an induced magnetic field, and generate a current I2 through the drive of the driving circuit 140, and generate a reverse magnetic field to offset the induced magnetic field of the above-mentioned current I1 to be measured. In some embodiments, the secondary side 112 may include an iron core 116 and a coil 117. The current conductor 115 may be arranged to pass through the iron core 116. The iron core 116 can sense the magnetic field generated by the primary side 111 and generate an induced magnetic field. In addition, the iron core 116 may have a gap 118. The coil 117 may be arranged on the iron core 116. The coil 117 can generate a current I2 through the drive of the driving circuit 140, and generate a reverse magnetic field.

[0049] The magnetic unit 113 may be disposed in the slot 118 of the iron core 116. The magnetic unit 113 may generate an analog signal Sa by sensing the induced magnetic field of the secondary side 112 (iron core 116). In this embodiment, the magnetic unit 113 may be a Hall sensor or other suitable sensors, but the present invention is not limited thereto.

[0050] The voltage generating unit 114 may be electrically connected to the secondary side 112. Specifically, the voltage generating unit 114 may have a first end and a second end, the first end of the voltage generating unit 114 may be electrically connected to the coil 117 of the secondary side 112, and the second end of the voltage generating unit 114 may be electrically connected to the ground. The voltage generating unit 114 may receive the current I2 generated by the coil 117 and generate a voltage output signal Vo. In this embodiment, the voltage generating unit 114 may be a resistor, but the present invention is not limited thereto.

[0051] In some embodiments, the first signal conversion unit 120 may include a first impedance unit 121, a second impedance unit 122 and an amplifier 123. Figure 3 As shown. The first impedance unit 121 has a first end and a second end. The first end of the first impedance unit 121 can be electrically connected to the magnetic unit 113 and receive the analog signal Sa. The second impedance unit 122 has a first end and a second end. The first end of the second impedance unit 122 can be electrically connected to the magnetic unit 113 and receive the analog signal Sa.

[0052] The amplifier 123 has a first input terminal, a second input terminal, a third input terminal, a fourth input terminal and an output terminal. The first input terminal of the amplifier 123 can be electrically connected to the second terminal of the first impedance unit 121. The second input terminal of the amplifier 123 can be electrically connected to the second terminal of the second impedance unit 122. The third input terminal of the amplifier 123 can receive a first reference voltage V1. The fourth input terminal of the amplifier 123 can receive a second reference voltage V2. The output terminal of the amplifier 123 can generate a control signal Sc. In some embodiments, the first impedance unit 121 and the second impedance unit 122 can be resistors, but the present invention is not limited to this. In addition, the first reference voltage V1 is, for example, a system voltage, and the second reference voltage V2 is, for example, a ground voltage, but the present invention is not limited to this.

[0053] In some embodiments, the driving circuit 140 may include a first transistor T1 and a second transistor T2. The first transistor T1 has a first end, a second end and a control end. The first end of the first transistor T1 can receive a first reference voltage V1. The second end of the first transistor T1 can be electrically connected to the current conversion unit 110 to be measured. Further, the second end of the first transistor T1 can be electrically connected to the coil 117 of the secondary side 112 of the current conversion unit 110 to be measured, so as to drive the coil 117 to generate a current I2. The control end of the first transistor T1 can be electrically connected to the first signal conversion unit 120. Further, the control end of the first transistor T1 can be electrically connected to the output end of the amplifier 123 of the first signal conversion unit 120, and receive the control signal Sc.

[0054] The second transistor T2 has a first end, a second end and a control end. The first end of the second transistor T2 can receive a second reference voltage V2. The second end of the second transistor T2 can be electrically connected to the second end of the first transistor T1. The control end of the second transistor T2 is electrically connected to the control end of the first transistor T1.

[0055] In this embodiment, the first transistor T1 can form a totem pole circuit. In addition, the first transistor T1 and the second transistor T2 can be bipolar junction transistors (BJT), wherein the first end of the first transistor T1 and the second transistor T2 is, for example, a collector end, the second end of the first transistor T1 and the second transistor T2 is, for example, an emitter end, and the control end of the first transistor T1 and the second transistor T2 is, for example, a base end, but the present invention is not limited thereto.

[0056] In other embodiments, the first transistor T1 and the second transistor T2 may be metal oxide semiconductor field effect transistors (MOSFET), wherein the first ends of the first transistor T1 and the second transistor T2 are, for example, drain ends, the second ends of the first transistor T1 and the second transistor T2 are, for example, source ends, and the control ends of the first transistor T1 and the second transistor T2 are, for example, gate ends.

[0057] Figure 3 is a block diagram of a digital closed-loop current sensor according to another embodiment of the present invention. Figure 3 The digital closed-loop current sensor 300 includes a current conversion unit 310, a first signal conversion unit 320, a second signal conversion unit 330, a control unit 340 and a driving circuit 350. In this embodiment, the current conversion unit 310, the second signal conversion unit 330 and the driving circuit 350 are connected to each other. Figure 1 The current conversion unit 110 to be measured and the second signal conversion unit 130 are the same or similar, and can be referred to Figure 1 In addition, the internal components of the current conversion unit 310 and their arrangement relationship are similar to those of the embodiment of FIG. Figure 2 The internal components and their setting relationship of the current conversion unit 110 to be tested are the same or similar, and can be referred to Figure 2 The embodiments of the present invention are described in detail, so they will not be repeated here.

[0058] The first signal conversion unit 320 can be electrically connected to the current conversion unit 310. The first signal conversion unit 320 can receive an analog signal Sa and convert the analog signal Sa into a digital signal Sd. In some embodiments, the first signal conversion unit 320 can be an analog-to-digital converter or a delta-sigma modulator, but the present invention is not limited thereto.

[0059] The control unit 340 can be electrically connected to the first signal conversion unit 320 and the second signal conversion unit 330. The control unit 340 can receive the digital signal Sd of the first signal conversion unit 320 and the digital voltage output signal Vod of the second signal conversion unit 330, and convert the digital signal Sd into a control signal Sc, and output the digital voltage output signal Vod. In addition, the digital voltage output signal Vod can be output to a subsequent circuit, so that the subsequent circuit obtains the value of the current to be measured and performs corresponding applications, wherein the subsequent circuit can be as follows Figure 1The control unit 150 shown may be other suitable processors or controllers, but the present invention is not limited thereto. In some embodiments, the control unit 340 may be a digital signal processor, an application specific integrated circuit, a microcontroller, or a field programmable logic gate array, but the present invention is not limited thereto.

[0060] The driving circuit 350 can be electrically connected to the control unit 340 and the current conversion unit 110 to be measured. The driving circuit 350 can receive the control signal Sc and generate a reverse magnetic field in the current conversion unit 110 to offset the induced magnetic field of the current I1 to be measured. In addition, the control signal Sc can be a pulse width modulation signal. In this way, the digital closed-loop current sensor 300 can have no residual magnetism, fast response, and can reduce the influence of electromagnetic interference on the digital closed-loop current sensor 300 and the driving power consumption, and reduce the use of the post-amplifier circuit and reduce the sampling noise and delay of the signal.

[0061] In some embodiments, the driving circuit 350 may include Figure 2 The first transistor T1 and the second transistor T2 of the driving circuit 350 are arranged in a relationship similar to that of Figure 2 Similar, but different in that, Figure 2 The control end of the first transistor T1 of the driving circuit 150 is electrically connected to the first signal conversion unit 120 and receives the control signal Sc, while the control end of the first transistor T1 of the driving circuit 350 of this embodiment can be electrically connected to the control unit 340 and receive the control signal Sc.

[0062] In summary, the digital closed-loop current sensor disclosed in the present invention converts the analog signal of the current conversion unit to be measured into a control signal through the first signal conversion unit, converts the voltage output signal of the current conversion unit to be measured into a digital voltage output signal to the control unit through the second signal conversion unit, and the driving circuit receives the control signal of the first signal conversion unit and generates a reverse magnetic field in the current conversion unit to be measured to offset the induced magnetic field of the current to be measured, or converts the analog signal of the current conversion unit to be measured into a digital signal through the first signal conversion unit, converts the voltage output signal of the current conversion unit to be measured into a digital voltage output signal through the second signal conversion unit, the control unit converts the digital signal of the first signal conversion unit into a control signal and outputs the digital voltage output signal of the second signal conversion unit, and the driving circuit receives the control signal of the control unit and generates a reverse magnetic field in the current conversion unit to offset the induced magnetic field of the current to be measured. In this way, the digital closed-loop current sensor can have no residual magnetism, fast response, and can reduce the influence of electromagnetic interference and driving power consumption of the digital closed-loop current sensor, and reduce the use of the post-amplifier circuit and reduce the sampling noise and delay of the signal.

[0063] Although the present invention is disclosed as above by the embodiments, it is not intended to limit the scope of the present invention. Any person with ordinary knowledge in the technical field can make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be based on the scope defined by the attached claims.

Claims

1. A digital closed-loop current sensor, suitable for use in combination with a control unit, characterized in that: The digital closed-loop current sensor includes: A current conversion unit to be measured, into which a current to be measured flows, and generates an analog signal and a voltage output signal through an induced magnetic field generated by the current to be measured; a first signal conversion unit, electrically connected to the current conversion unit to be measured, and converting the analog signal into a control signal; a second signal conversion unit, electrically connected to the current conversion unit to be measured, receiving the voltage output signal and converting it into a digital voltage output signal, the second signal conversion unit is electrically connected to the control unit, the control unit receives the digital voltage output signal and obtains the value of the current to be measured; and A driving circuit is electrically connected to the first signal conversion unit and the current conversion unit to be measured, receives the control signal and generates a reverse magnetic field in the current conversion unit to be measured to offset the induced magnetic field of the current to be measured.

2. The digital closed-loop current sensor according to claim 1, characterized in that: The first signal conversion unit is a proportional-integral controller or a proportional-integral-derivative controller.

3. The digital closed-loop current sensor according to claim 1, characterized in that: The second signal conversion unit is an analog-to-digital converter or a delta-sigma modulator.

4. The digital closed-loop current sensor according to claim 1, characterized in that: The current conversion unit to be measured includes: a primary side for the waiting side current to flow into and generate a magnetic field; The primary and secondary sides sense the magnetic field and generate an induced magnetic field, and generate a current through the driving of the driving circuit, and generate the reverse magnetic field; a magnetic unit, generating an analog signal through the induced magnetic field; and A voltage generating unit is electrically connected to the secondary side, receives the current and generates the voltage output signal.

5. The digital closed-loop current sensor according to claim 1, characterized in that: The driving circuit includes: a first transistor having a first end, a second end and a control end, the first end of the first transistor receiving a first reference voltage, the second end of the first transistor being electrically connected to the current conversion unit to be measured, and the control end of the first transistor being electrically connected to the first signal conversion unit; and A second transistor has a first end, a second end and a control end, the first end of the second transistor receives a second reference voltage, the second end of the second transistor is electrically connected to the second end of the first transistor, and the control end of the second transistor is electrically connected to the control end of the first transistor.

6. A digital closed-loop current sensor, characterized in that: include: A current conversion unit to be measured, into which a current to be measured flows, and generates an analog signal and a voltage output signal through an induced magnetic field generated by the current to be measured; a first signal conversion unit, electrically connected to the current conversion unit to be measured, and converting the analog signal into a digital signal; a second signal conversion unit, electrically connected to the current conversion unit to be measured, receiving the voltage output signal and converting it into a digital voltage output signal; a control unit, electrically connected to the first signal conversion unit and the second signal conversion unit, receiving the digital signal and the digital voltage output signal, converting the digital signal into a control signal, and outputting the digital voltage output signal to output the value of the current to be measured; as well as A driving circuit is electrically connected to the control unit and the current conversion unit to be measured, receives the control signal and generates a reverse magnetic field in the current conversion unit to be measured to offset the induced magnetic field of the current to be measured.

7. The digital closed-loop current sensor according to claim 6, characterized in that: The first signal conversion unit is an analog-to-digital converter or a delta-sigma modulator.

8. The digital closed-loop current sensor according to claim 6, characterized in that: The second signal conversion unit is an analog-to-digital converter or a delta-sigma modulator.

9. The digital closed-loop current sensor according to claim 6, characterized in that: The current conversion unit to be measured includes: a primary side for the waiting side current to flow into and generate a magnetic field; The primary and secondary sides sense the magnetic field and generate an induced magnetic field, and generate a current through the driving of the driving circuit, and generate the reverse magnetic field; a magnetic unit, generating an analog signal through the induced magnetic field; and A voltage generating unit is electrically connected to the secondary side, receives the current and generates the voltage output signal.

10. The digital closed-loop current sensor according to claim 6, characterized in that: The driving circuit includes: a first transistor having a first end, a second end and a control end, the first end of the first transistor receiving a first reference voltage, the second end of the first transistor being electrically connected to the current conversion unit to be measured, and the control end of the first transistor being electrically connected to the control unit; and A second transistor has a first end, a second end and a control end, the first end of the second transistor receives a second reference voltage, the second end of the second transistor is electrically connected to the second end of the first transistor, and the control end of the second transistor is electrically connected to the control end of the first transistor.

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