CN106841749B - It is a kind of to realize two-way high-side current detection circuit using single amplifier - Google Patents
It is a kind of to realize two-way high-side current detection circuit using single amplifier Download PDFInfo
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- CN106841749B CN106841749B CN201710079375.5A CN201710079375A CN106841749B CN 106841749 B CN106841749 B CN 106841749B CN 201710079375 A CN201710079375 A CN 201710079375A CN 106841749 B CN106841749 B CN 106841749B
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
Abstract
Two-way high-side current detection circuit is realized using single amplifier the invention discloses a kind of, comprising: current detection circuit is connected between energy storage device and load, to complete the sampling of bidirectional current, and charge/discharge current is converted to voltage difference；Control circuit, for the control signal mcu from microprocessor to be converted to switch arrays control signal；Switch arrays, for the voltage difference that the current detection circuit exports to be transferred to the input terminal of amplifying circuit under the control of switch arrays control signal；Amplifying circuit, the voltage difference transmitted through the switch arrays for exporting the current detection circuit is amplified and is filtered to carry out subsequent processing, the present invention is measured by that can be completed the high-side current of two different directions using an operational amplifier and a current detection circuit, it ensure that the measurement accuracy of both direction is completely the same, error and precision asymmetry problem be not present.
Description
Technical field
The present invention relates to a kind of high-side current detection circuits, realize two-way high-end electricity using single amplifier more particularly to a kind of
Current detection circuit.
Background technique
High-end (referring to power positive end) current detecting can solve low side (referring to power cathode end), and detection scheme is because of cathode
Line interference causes measurement to be fluctuated, the big problem of measurement error.Much need Precision measurement electric so superior MCU is used in
The occasion of stream, especially current fluctuation are violent, interfere compared in overall situation, such as new energy vehicle.It is fully developed in science and technology
In the case of, mobile communication equipment and the new energy vehicles become the essential part of daily life, chargeable energy storage device
It is widely used, the amplitude for being charged and discharged electric current must be fully considered to guarantee safety, quick charge and peace using design
Otherwise complete and sustainable electric discharge easily causes chargeable energy storage device damage even to explode, therefore superior MCU becomes especially
It is important.
Conventional superior MCU needs two groups of amplifiers and detection measuring circuit to complete two different directions respectively
Current detecting (charging direction and course of discharge), is as shown in Figure 1 the circuit structure diagram of traditional high-side current detection circuit.It passes
The current detection circuit of system is respectively completed the current detecting for being charged and discharged both direction, amplifier U by two amplifiersC, resistance
RINC+、RINC-, metal-oxide-semiconductor QC, filter capacitor CCAnd output resistance ROUTCForm charging current detecting circuit, amplifier UD, resistance
RIND+、RIND-, metal-oxide-semiconductor QD, filter capacitor CDAnd output resistance ROUTDForm discharge current testing circuit, RSENSEFor electric current inspection
Sensor is surveyed, LOAD is power load, VBATFor chargeable energy storage device, CHARGER is charger, current detection sensor
RSENSEBoth ends be separately connected the input resistance R of charging current detecting circuitINC+、RINC-One end and discharge current testing circuit
Input resistance RIND+、RIND-One end, resistance RINC-The other end be connected to amplifier UCInverting input terminal, metal-oxide-semiconductor QCSource
Pole and substrate, resistance RINC+The other end be connected to amplifier UCNon-inverting input terminal, amplifier UCOutput end be connected to metal-oxide-semiconductor QC
Grid, metal-oxide-semiconductor QCDrain electrode be connected to output resistance ROUTCOne end, filter capacitor CCOne end connects current detection sensor
RSENSEThe power positive end of anode (left end, electric current flows from left to right when charging) and amplifier, the other end are connected to the whole of amplifier
Flow end VREG, output resistance ROUTCThe other end and amplifier power supply negative terminal ground connection, resistance RIND-The other end be connected to amplifier UD's
Inverting input terminal, metal-oxide-semiconductor QDSource electrode and substrate, resistance RIND+The other end be connected to amplifier UDNon-inverting input terminal, amplifier UD
Output end be connected to metal-oxide-semiconductor QDGrid, metal-oxide-semiconductor QDDrain electrode be connected to output resistance ROUTDOne end, filter capacitor CDOne
End connection current detection sensor RSENSEThe power positive end of anode (right end, electric current flows from right to left when charging) and amplifier,
The other end is connected to amplifier UDRectifier terminal VREG, output resistance ROUTDThe other end and amplifier power supply negative terminal ground connection.
However, since 2 groups of circuits must there may be non complete symmetry problem, being led in traditional current detection circuit
Cause the measurement error of two different directions circuits will not be completely the same, this can attract serious accumulation on needing accurate measurement and miss
Difference, it is of course also possible to take other methods to calibrate this error, but calibration program error itself can be bigger.
Summary of the invention
In order to overcome the deficiencies of the above existing technologies, it is double using single amplifier realization that purpose of the present invention is to provide a kind of
To high-side current detection circuit, by the way that two can be completed not using an operational amplifier and a current detection circuit
Equidirectional high-side current measurement, ensure that the measurement accuracy of both direction is completely the same, and there is no error and precision are asymmetric
Property problem, the present invention can reduce circuit cost, improve product cost.
In view of the above and other objects, the present invention proposes that a kind of single amplifier of utilization realizes two-way high-side current detection circuit,
Include:
Current detection circuit is connected between energy storage device and load, to complete the sampling of bidirectional current, and by discharge/charge
Electric current is converted to voltage difference；
Control circuit, for the control signal mcu from microprocessor to be converted to switch arrays control signal；
Switch arrays, the voltage difference for exporting the current detection circuit under the control of switch arrays control signal
It is transferred to the input terminal of amplifying circuit；
Amplifying circuit, the voltage difference transmitted through the switch arrays for exporting the current detection circuit amplify and
Filtering is to carry out subsequent processing.
Further, which completes the sampling of bidirectional current as current sensor, and charge/discharge is electric
Circulation is changed to voltage difference.
Further, which includes the small resistance of an accurate resistance value, is connected to energy storage device and load
Between, and connect the switch arrays.
Further, which includes the first triode, the second triode and first to fourth resistance, the control
Signal mcu is connected to the base stage of first triode through the first resistor, and the emitter of first triode connects through 3rd resistor
Ground, the collector of first triode are connected with the base stage of second triode and are connected to power supply through the 3rd resistor, this
The emitter of two triodes connects power supply, and the collector of second triode connects the switch arrays and through the 4th resistance eutral grounding.
Further, which is NPN triode, which is PNP triode.
Further, which includes third to the 6th metal-oxide-semiconductor, the drain electrode of the third metal-oxide-semiconductor, the 6th metal-oxide-semiconductor
Source electrode and substrate are connected to the anode of energy storage device, and the drain electrode of the 4th metal-oxide-semiconductor, the source electrode of the 5th metal-oxide-semiconductor and substrate are connected to
The anode of load, the drain electrode of the source electrode and substrate, the 5th metal-oxide-semiconductor of the third metal-oxide-semiconductor are connected to the amplifying circuit, the 4th MOS
The drain electrode of the source electrode and substrate, the 6th metal-oxide-semiconductor of pipe is connected to the amplifying circuit, the grid connection of the third to the 6th metal-oxide-semiconductor
To the collector of second triode.
Further, the third metal-oxide-semiconductor and the 4th metal-oxide-semiconductor are NMOS tube, and the 5th metal-oxide-semiconductor is with the 6th metal-oxide-semiconductor
PMOS tube.
Further, which includes operational amplifier, the 7th PMOS tube and filter circuit, the operational amplifier
Two input terminals connect the switch arrays, the output end of the operational amplifier is connected to the grid of the 7th PMOS tube, the 7th
The source electrode and substrate of PMOS tube are connected to the inverting input terminal of the operational amplifier, and the drain electrode of the 7th PMOS tube connects the filtering
Circuit, the negative power end ground connection of the operational amplifier.
Further, the drain electrode of the source electrode of the third metal-oxide-semiconductor and substrate, the 5th metal-oxide-semiconductor is connected to this through the 6th resistance
The drain electrode of the non-inverting input terminal of operational amplifier, the source electrode and substrate, the 6th metal-oxide-semiconductor of the 4th NMOS tube connects through the 7th resistance
It is connected to the inverting input terminal of the operational amplifier.
Further, the 9th resistance is connected across between the output end of the operational amplifier and inverting input terminal for eliminating certainly
Swash.
Compared with prior art, the present invention is a kind of realizes two-way high-side current detection circuit by utilizing one using single amplifier
A operational amplifier and a current detection circuit complete the high-side current measurement of two different directions, ensure that both direction
Measurement accuracy it is completely the same, be not present error and precision asymmetry problem, meanwhile, by the invention it is possible to reduce circuit
Cost improves product cost.
Detailed description of the invention
Fig. 1 is the circuit structure diagram of traditional high-side current detection circuit；
Fig. 2 is a kind of circuit structure diagram that two-way high-side current detection circuit is realized using single amplifier of the present invention.
Specific embodiment
Below by way of specific specific example and embodiments of the present invention are described with reference to the drawings, those skilled in the art can
Understand further advantage and effect of the invention easily by content disclosed in the present specification.The present invention can also pass through other differences
Specific example implemented or applied, details in this specification can also be based on different perspectives and applications, without departing substantially from
Various modifications and change are carried out under spirit of the invention.
Fig. 2 is a kind of circuit structure diagram that two-way high-side current detection circuit is realized using single amplifier of the present invention.Such as Fig. 2 institute
Show, the present invention is a kind of to realize two-way high-side current detection circuit using single amplifier, comprising: current detection circuit 10, control circuit
20, switch arrays 30 and amplifying circuit 40.
Wherein, current detection circuit 10 uses the small resistance (R8) of accurate resistance value two-way to complete as current sensor
The sampling of (charging and discharging) electric current, and charge/discharge current is converted into voltage difference；Control circuit 20 by NPN triode Q1,
PNP triode Q2 and four resistance R1-R4 compositions, for the control signal mcu from microprocessor to be converted to switch arrays
Column control signal；Switch arrays 30 are made of NMOS tube Q3-Q4 and PMOS tube Q5-Q6, for controlling signal in switch arrays
Control under the voltage difference that current detection circuit 10 exports is transferred to the input terminal of amplifying circuit 40；Amplifying circuit 40 is by operation
Amplifier JP1, PMOS tube Q7, filter capacitor C1 and resistance R5, R6, R7, R9 composition, for exporting current detection circuit 10
The voltage difference transmitted through switch arrays 30 amplify and filter to carry out subsequent processing.
Specifically, the control signal mcu from microprocessor is connected to the base stage of NPN triode Q1, NPN through resistance R1
The emitter of triode Q1 is grounded through resistance R3, and the collector of NPN triode Q1 is connected and through electricity with the base stage of PNP triode Q2
Resistance R3 is connected to power supply VCC, and the emitter of PNP triode Q2 meets power supply VCC, and the collector of PNP triode Q2 connects NMOS tube
Q3, Q4 and the grid of PMOS tube Q5, Q6 are simultaneously grounded through resistance R4, and the drain electrode of NMOS tube Q3, the source electrode of PMOS tube Q6 and substrate connect
Be connected to the anode B+ i.e. left end of current sensor R8 of energy storage device (not shown), the drain electrode of NMOS tube Q4, PMOS tube Q5 source
Pole and substrate are connected to the anode Load+ i.e. right end of current sensor R8 of load (not shown), the source electrode and lining of NMOS tube Q3
The drain electrode at bottom, PMOS tube Q5 is connected to the non-inverting input terminal of amplifier JP1, source electrode and substrate, the PMOS of NMOS tube Q4 through resistance R6
The drain electrode of pipe Q6 is connected to the inverting input terminal of amplifier JP1 through resistance R7, and resistance R9 is connected across the output end of amplifier JP1 and anti-
For eliminating self-excitation between phase input terminal, the output end of amplifier JP1 is connected to the grid of PMOS tube Q7, the source electrode of PMOS tube Q7
The inverting input terminal of amplifier JP1, one end of drain electrode connection the resistance R5 and filter capacitor C1 of PMOS tube Q7, electricity are connected to substrate
Hinder the other end ground connection of R5 and filter capacitor C1, the negative power end ground connection of amplifier JP1, positive supply termination power VCC.
In the specific embodiment of the invention, Q3, Q4 are NMOS tube, and Q5, Q6 are PMOS tube, control signal mcu through tri- pole NPN
Pipe Q1 and PNP triode Q2 is generated after reverse phase twice is suitble to the switch arrays of control switch array to control signal, when charging, electric current
B+ is flowed to from Load+, the control signal mcu from microprocessor is high level, the conducting of NMOS tube Q3, Q4, circuit measuring at this time
Charging current, when electric discharge, electric current flows to Load+ from B+, and the control signal mcu from microprocessor is low level, PMOS at this time
Pipe Q5, Q6 conducting, circuit measuring discharge current.
Q1, Q2 are respectively pnp triode and Npn triode, they and resistance R1, R2, R3, R4 form N-mos and P-mos
Control switching circuit.When Mcu input high level, N-MOS conducting is switched to charging current measurement.When Mcu exports low level, P-
Metal-oxide-semiconductor conducting is switched to discharge current measurement.
In the present invention, voltage Vt1=R5/R7*Ic*R8 is measured, so electric current Ic=Vt1*R7/ to be measured (R5*R8).
Realize two-way high-side current detection circuit by utilizing an operation using single amplifier in conclusion the present invention is a kind of
Amplifier and a current detection circuit complete the high-side current measurement of two different directions, ensure that the measurement of both direction
Precision is completely the same, and error and precision asymmetry problem is not present, meanwhile, by the invention it is possible to reduce circuit cost, mention
High product cost performance.
The above-described embodiments merely illustrate the principles and effects of the present invention, and is not intended to limit the present invention.Any
Without departing from the spirit and scope of the present invention, modifications and changes are made to the above embodiments by field technical staff.Therefore,
The scope of the present invention, should be as listed in the claims.
Claims (7)
1. a kind of circuit for realizing two-way superior MCU using single amplifier, comprising:
Current detection circuit is connected between energy storage device and load, to complete the sampling of bidirectional current, and charge/discharge is electric
Circulation is changed to voltage difference；
Control circuit, for the control signal mcu from microprocessor to be converted to switch arrays control signal；
Switch arrays, the voltage difference for exporting the current detection circuit under the control of switch arrays control signal are transmitted
To the input terminal of amplifying circuit；
Amplifying circuit, the voltage difference transmitted through the switch arrays for exporting the current detection circuit are amplified and are filtered
To carry out subsequent processing；
Wherein, the control circuit include the first triode, the second triode and first resistor, second resistance, 3rd resistor and
4th resistance, the control signal mcu are connected to the base stage of first triode through the first resistor, the transmitting of first triode
Pole is grounded through 3rd resistor, and the collector of first triode is connected with the base stage of second triode and connects through the second resistance
It is connected to power supply, the emitter of second triode connects power supply, and the collector of second triode connects the switch arrays and through being somebody's turn to do
4th resistance eutral grounding；
The switch arrays include third metal-oxide-semiconductor, the 4th metal-oxide-semiconductor, the 5th metal-oxide-semiconductor and the 6th metal-oxide-semiconductor, the drain electrode of the third metal-oxide-semiconductor,
The source electrode and substrate of 6th metal-oxide-semiconductor are connected to the anode of energy storage device, the drain electrode of the 4th metal-oxide-semiconductor, the source electrode of the 5th metal-oxide-semiconductor and
Substrate is connected to the anode of load, and the drain electrode of the source electrode and substrate, the 5th metal-oxide-semiconductor of the third metal-oxide-semiconductor is connected to the amplifying circuit,
The drain electrode of the source electrode and substrate, the 6th metal-oxide-semiconductor of 4th metal-oxide-semiconductor is connected to the amplifying circuit, the third metal-oxide-semiconductor, the 4th MOS
The grid of pipe, the 5th metal-oxide-semiconductor and the 6th metal-oxide-semiconductor is connected to the collector of second triode；
The amplifying circuit includes operational amplifier, the 7th PMOS tube and filter circuit, and two input terminals of the operational amplifier connect
The switch arrays are connect, the output end of the operational amplifier is connected to the grid of the 7th PMOS tube, the source electrode of the 7th PMOS tube
The inverting input terminal of the operational amplifier is connected to substrate, the drain electrode of the 7th PMOS tube connects the filter circuit, the operation
The negative power end of amplifier is grounded.
2. a kind of circuit for realizing two-way superior MCU using single amplifier as described in claim 1, it is characterised in that: should
Current detection circuit completes the sampling of bidirectional current as current sensor, and charge/discharge current is converted to voltage difference.
3. a kind of circuit for realizing two-way superior MCU using single amplifier as claimed in claim 2, it is characterised in that: should
Current detection circuit includes the small resistance of an accurate resistance value, is connected between energy storage device and load, and connect the switch arrays
Column.
4. a kind of circuit for realizing two-way superior MCU using single amplifier as described in claim 1, it is characterised in that: should
First triode is NPN triode, which is PNP triode.
5. a kind of circuit for realizing two-way superior MCU using single amplifier as described in claim 1, it is characterised in that: should
Third metal-oxide-semiconductor and the 4th metal-oxide-semiconductor are NMOS tube, and the 5th metal-oxide-semiconductor and the 6th metal-oxide-semiconductor are PMOS tube.
6. a kind of circuit for realizing two-way superior MCU using single amplifier as described in claim 1, it is characterised in that: should
The drain electrode of the source electrode and substrate, the 5th metal-oxide-semiconductor of third metal-oxide-semiconductor is connected to the homophase input of the operational amplifier through the 6th resistance
End, the drain electrode of the source electrode and substrate, the 6th metal-oxide-semiconductor of the 4th NMOS tube are connected to the anti-of the operational amplifier through the 7th resistance
Phase input terminal.
7. a kind of circuit for realizing two-way superior MCU using single amplifier as described in claim 1, it is characterised in that: the
Nine resistance are connected across between the output end of the operational amplifier and inverting input terminal for eliminating self-excitation.
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| CN201710079375.5A CN106841749B (en) | 2017-02-14 | 2017-02-14 | It is a kind of to realize two-way high-side current detection circuit using single amplifier |
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| CN201710079375.5A CN106841749B (en) | 2017-02-14 | 2017-02-14 | It is a kind of to realize two-way high-side current detection circuit using single amplifier |
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| CN106841749B true CN106841749B (en) | 2019-09-17 |
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Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108845181A (en) * | 2018-07-09 | 2018-11-20 | 珠海市微半导体有限公司 | current detection circuit and detection method |
| CN109030928A (en) * | 2018-07-09 | 2018-12-18 | 珠海市微半导体有限公司 | For carrying out the circuit and electric current detecting method of bidirectional current detection |
| CN109900950B (en) * | 2019-04-04 | 2021-07-13 | 上海南芯半导体科技有限公司 | High-precision continuous-time bidirectional current sampling circuit and implementation method |
| CN110261661B (en) * | 2019-04-18 | 2022-06-14 | 矽力杰半导体技术(杭州)有限公司 | Current detection circuit and power converter |
| CN110018336B (en) * | 2019-04-24 | 2021-02-05 | 上海类比半导体技术有限公司 | Bidirectional sampling circuit and sampling method |
| CN113125830B (en) * | 2019-12-30 | 2023-06-09 | 圣邦微电子（北京）股份有限公司 | Bidirectional current detection circuit and power supply system |
| CN113325217B (en) * | 2021-04-23 | 2022-08-12 | 上海卫星工程研究所 | Microsecond level initiating explosive device ignition current detection circuit based on single operational amplifier |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS58218658A (en) * | 1982-06-14 | 1983-12-19 | Nippon Telegr & Teleph Corp <Ntt> | Current detecting circuit |
| CN1748150A (en) * | 2003-02-12 | 2006-03-15 | 皇家飞利浦电子股份有限公司 | Current monitoring system using bi-directional current sensor |
| CN102214993A (en) * | 2010-04-09 | 2011-10-12 | 松下电器产业株式会社 | Load drive circuit with current bidirectional detecting function |
| TW201205088A (en) * | 2010-05-27 | 2012-02-01 | Standard Microsyst Smc | Bi-directional high side current sense measurement |
| CN202421297U (en) * | 2012-01-18 | 2012-09-05 | 长春大学 | Direct current voltage-stabilizing device for performing high-side current detection |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6621259B2 (en) * | 2001-05-30 | 2003-09-16 | Texas Instruments Incorporated | Current sense amplifier and method |
| US6982559B2 (en) * | 2004-01-14 | 2006-01-03 | Kyocera Wireless Corp. | Accurate and efficient sensing circuit and method for bi-directional signals |
-
2017
- 2017-02-14 CN CN201710079375.5A patent/CN106841749B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS58218658A (en) * | 1982-06-14 | 1983-12-19 | Nippon Telegr & Teleph Corp <Ntt> | Current detecting circuit |
| CN1748150A (en) * | 2003-02-12 | 2006-03-15 | 皇家飞利浦电子股份有限公司 | Current monitoring system using bi-directional current sensor |
| CN102214993A (en) * | 2010-04-09 | 2011-10-12 | 松下电器产业株式会社 | Load drive circuit with current bidirectional detecting function |
| TW201205088A (en) * | 2010-05-27 | 2012-02-01 | Standard Microsyst Smc | Bi-directional high side current sense measurement |
| CN202421297U (en) * | 2012-01-18 | 2012-09-05 | 长春大学 | Direct current voltage-stabilizing device for performing high-side current detection |
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