CN105785101B - A kind of efficient inductive current detection circuit - Google Patents
A kind of efficient inductive current detection circuit Download PDFInfo
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- CN105785101B CN105785101B CN201610123784.6A CN201610123784A CN105785101B CN 105785101 B CN105785101 B CN 105785101B CN 201610123784 A CN201610123784 A CN 201610123784A CN 105785101 B CN105785101 B CN 105785101B
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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
- G01R19/0092—Arrangements for measuring currents or voltages or for indicating presence or sign thereof measuring current only
Abstract
The present invention discloses a kind of efficient inductive current detection circuit, including sequentially connected inductive current size judgment mechanism circuit, big inductive current detection circuit and current mirroring circuit, further includes the small inductor current detection circuit in parallel with big inductive current detection circuit；Inductive current size judgment mechanism circuit is used to judge to flow through the magnitude relationship of the size and preset critical value of the electric current of inductance, and exports judgment mechanism signal；To select big inductive current detection circuit or small inductor current detection circuit to be detected inductive current.Inductive current circuit disclosed by the invention is suitable for the inductive current circuit of BOOST DC DC converters, it not only can be with the big inductive current of efficient detection, extremely low inductive current can also be effectively detected, in large load current, inductive current is pressed into N times of scale smaller；Under current conditions, inductive current is slightly being pressed into N/2 scale smallers.To improve the accuracy of output end detection well.
Description
Technical field
The present invention relates to current detection circuit fields, more particularly, to a kind of efficient inductive current detection circuit.
Background technology
As battery powered portable electronic product constantly develops to low-voltage, low-power consumption, high current direction, to switch
The low-power consumption of power supply chip and high efficiency requirement are harsher, and the power consumption and transfer efficiency of chip largely determine battery
Service efficiency and the service life.It is therefore desirable to reduce the power consumption of each function module in Switching Power Supply, to improve portable device
Stand-by time.
Inductive current detection circuit is one of most important function module in Switching Power Supply, it can detect load in real time and open
Road, short circuit and over-current state, to realize chip protection and Save power consumption.In the DC-DC converter of Controlled in Current Mode and Based, electricity
Current detection circuit is important comprising modules.It not only acts as overcurrent protection in entire circuit, and by current detecting
As a result slope compensation signal is added compared with the output of voltage loop, realizes pulse width modulation, precision, speed and power consumption pair
Circuit integrity can have and have a significant impact.
A variety of different inductive current detection techniques exist in the prior art, electric current detecting method popular at present has
Three kinds of series resistance detection, power tube MN detections and survey of parallel-current microscopy etc..
Series resistance detection is in one small sampling resistor of piece external inductance or the series connection of power tube one end, because for certain
Resistance value, by the pressure drop in detection resistance i.e. can detect that the electric current flowed through on corresponding inductance.This method accuracy of detection
Height, but since the presence of detection resistance can introduce an additional power consumption, to reduce power supply conversion efficiency, therefore, the electricity
Resistance cannot be too big, and this method is also only applicable to low current detection circuit, and at the same time, low resistance is influenced precision not by technique
It is enough.
Power tube MN detections are realized by detecting the voltage on power tube, because power tube is operated in linear zone, therefore
It can be equivalent to a resistanceThis method is without extra power consumption, but μ, Cox and VTEtc. parameters by
The influence of temperature changes greatly, and the MN of power tube will produce nonlinear variation, and worst error range reachable -50%~+
100%, thus current detection accuracy is poor.
Parallel-current microscopy survey be by one in parallel and detection pipe of the power tube with same type, breadth length ratio N: 1,
In this way, the electric current for flowing through detection pipe is just the 1/N of power tube current.This method needs op-amp, makes detection pipe and work(
The current mirror that rate pipe is constituted has good matching, therefore circuit structure is more complicated, and bandwidth is relatively low, and the response time is slower, right
The matching of circuit is more demanding.
In current practical application, the most commonly used is parallel-current mirror detection method, it is in parallel that Fig. 1 show a kind of typical case
The inductive current detection method of current mirror.
VN is pwm control signal in Fig. 1, and VP and VN are complementary signals, this circuit operation principle is when VN is high level
When, power tube MN conductings, N4 and N5 conductings, N3 are closed, and P2 and P3 provide identical electric current as current source to N1 and N2, if
As the breadth length ratio setting of two NMOS tubes of N1 and N2, then two pipe source level current potentials are equal, and such N4 and MN are with equal
Drain voltage, so the size of current proportionate relationship for flowing through two pipes is：
It is arranged that P4 is equal with the breadth length ratio of P7 with P5, P6, then flowing through the electric current of detection resistance：
ISENSE=IN4_Ib
Since reference current is much smaller than the electric current of inductance detection, so ISENSE≈IN4, then：
VSENSE=ISENSE*RSENSE≈IN4*RSENSE
It can be seen that make ISENSEMore than 0, then IN4-Ib>0 i.e. IN4>Ib, thus the current detection circuit cannot be used for electricity
Feel too little current situation so that the circuit is restricted on loading range.
Invention content
The main object of the present invention is to provide a kind of efficient inductive current detection circuit, it is intended to be solved in inductive current detection
It can not be detected since inductive current is too small or accuracy of detection is not high, power consumption is big problem.It can be sentenced according to inductive current size
Off line selection circuit is operated in checking of great current pattern or low current detection pattern, to improve inductance detection efficiency and
Accuracy.
In order to solve the above technical problems, technical scheme is as follows：
A kind of efficient inductive current detection circuit, the inductive current detection circuit include sequentially connected inductive current
Size judgment mechanism circuit, big inductive current detection circuit and the first current mirroring circuit further include detecting electricity with big inductive current
The small inductor current detection circuit of road parallel connection；
Inductive current size judgment mechanism circuit, the size and preset critical value of the electric current for judging to flow through inductance
Magnitude relationship, and export judgment mechanism signal；
Big inductive current detection circuit, for detect inductive current it is bigger when flow through the current signal of inductance；
Small inductor current detection circuit, for detect inductive current it is smaller when flow through the current signal of inductance；
First current mirroring circuit, it is preset in the constant current equal with reference current and judgment mechanism circuit for generating
Reference voltage value；
The big inductive current detection circuit includes three groups of NMOS tubes for being operated in depth linear zone, being total to containing negative-feedback
Grid grade amplifying circuit, the second current mirroring circuit, the electric current summation circuit formed by NMOS tube N7 and NMOS tube N8；
Three groups are operated in the NMOS tube of depth linear zone, and first group of NMOS tube is NMOS tube N5 and NMOS tube N6, NMOS
The grid of pipe N5 and NMOS tube N6 meet drive signal CLKN；Second group of NMOS tube is power switch tube MP and NB, and the drain electrode of MP connects
The drain electrode of NMOS tube N6, the drain electrode that the grid of MP meets drive signal CLKP, NB connect the drain electrode of NMOS tube N5, the source electrode ground connection of NB,
The grid of NB meets the judgment mechanism signal vm of inductive current size judgment mechanism circuit output；Third group NMOS tube is NMOS tube N1
It is connected with the grid of NMOS tube N2 with NMOS tube N2, NMOS tube N1, the drain electrode of NMOS tube N1 connects the source level of NMOS tube N5, NMOS tube
The source electrode of N1 is grounded, and the drain electrode that the grid of NMOS tube N1 meets judgment mechanism signal vm, NMOS tube N2 connects the source level of NMOS tube N6,
The source electrode of NMOS tube N2 is grounded, and the grid of NMOS tube N2 meets judgment mechanism signal vm；
Total grid grade amplifying circuit containing negative-feedback includes by PMOS tube P0, PMOS tube P1 and NMOS tube N3, NMOS tube N4 groups
At total grid grade amplifying circuit and the negative feedback loop that is made of PMOS tube P7 and NMOS tube N5, NMOS tube N3；PMOS tube P0,
The grid of PMOS tube P1 connects, PMOS tube P0, PMOS tube P1 source electrode connect power supply, the drain electrode of PMOS tube P0 connects the leakage of NMOS tube N3
Pole, the drain electrode of PMOS tube P1 connect the drain electrode of NMOS tube N4, and the grid of NMOS tube N3 is connected with the grid of NMOS tube N4, drain electrode,
The source electrode of NMOS tube N3 is connect with the drain electrode of NMOS tube N1, and the source electrode of NMOS tube N4 is connect with the drain electrode of NMOS tube N2；PMOS tube
The grid of P7 connects the drain electrode of NMOS tube N3, and the drain electrode of PMOS tube P7 connects the drain electrode of NMOS tube N5；
Second current mirroring circuit includes NMOS tube N7, NMOS tube N8, the drain and gate connection of NMOS tube N7, NMOS tube N7
Source electrode ground connection, the drain electrode of NMOS tube N8 connects the source electrode of PMOS tube P7, and the source electrode of NMOS tube N8 is grounded；Flow through the electricity of NMOS tube N8
Stream is proportional to reference current；
The electric current summation circuit by the drain current for flowing through NB, NMOS tube N5 and NMOS tube N8 is cumulative obtain required for
Inductance detection electric current.
In a kind of preferably scheme, the small inductor current detection circuit includes two groups and is operated in depth linear zone
NMOS tube, total grid grade amplifying circuit, two groups of third current mirroring circuits containing negative-feedback；
Two groups of NMOS tubes for being operated in depth linear zone, first group is power switch tube MP and NL, and the drain electrode of NL meets NMOS
The drain electrode of pipe N5, the grid of NL meet the judgment mechanism signal vk of inductive current size judgment mechanism circuit output；Second group of NMOS
Pipe is NMOS tube N5 and NMOS tube N6, and the grid of NMOS tube N5 and NMOS tube N6 all meet drive signal CLKN；
Total grid grade amplifying circuit containing negative-feedback includes by PMOS tube P0, PMOS tube P1 and NMOS tube N3, NMOS tube N4 groups
At total grid grade amplifying circuit and the negative feedback loop that is made of PMOS tube P7 and NMOS tube N5, NMOS tube N3；
In two groups of third current mirroring circuits, one of which is made of NMOS tube N7 and NMOS tube N9, and another group by NMOS tube
N7 and NMOS tube N10 compositions, the electric current for flowing through NMOS tube N9 and NMOS tube N10 and reference current phase are obtained by current mirror
Deng.
In a kind of preferably scheme, first current mirroring circuit further includes reference current source IBIAS and PMOS tube
P0, PMOS tube P1, PMOS tube P3, PMOS tube P4, PMOS tube P5, PMOS tube P6；
PMOS tube P3 is connected with the grid of PMOS tube P4, and the source electrode of PMOS tube P3 and PMOS tube P4 meet power supply, PMOS tube P3
Drain electrode connect the drain electrode of NMOS tube N7, the drain and gate connection of PMOS tube P4, the drain electrode of PMOS tube P4 connects reference current source
One end of IBIAS, the other end ground connection of reference current source IBIAS；The drain electrode of PMOS tube P5 and PMOS tube P6 connect power supply, PMOS tube
P5 is connected with the grid of PMOS tube P6, after the grid of PMOS tube P6 source electrode connection after also respectively with the drain electrode of NMOS tube N8 and PMOS
The source electrode of pipe P7 connects.
In a kind of preferably scheme, the inductive current size judgment mechanism circuit includes generating to preset inductive current
Circuit, comparator COM, driving circuit Driver, reverser and the transmission gate circuit of critical value；
The circuit of critical current mode value is preset in the generation, passes through the electric current being made of PMOS tube P4, PMOS tube P2
Mirror and the NMOS tube Nref for being operated in linear zone generate the matched benchmark electricity of node voltage corresponding with default inductive current
It presses Vref, the grid of Nref to connect power supply, is operated in linear zone, the source electrode of PMOS tube P2 connects power supply, the grid difference of PMOS tube P2
It is connect with the grid of PMOS tube P0, PMOS tube P1, PMOS tube P3, PMOS tube P4, the source electrode ground connection of Nref, the grid of Nref connects electricity
Source, the drain electrode connection of PMOS tube P2 and Nref are followed by the reverse input end of comparator COM；
Comparator COM positive inputs meet the switching node sw of BOOST Switching Power Supplies, i.e. the drain electrode Vsw of MN pipes, reversed defeated
Enter to terminate preset reference voltage V ref, the input terminal vn of output termination driving circuit Driver；Driving circuit Driver and anti-
Inductive current size judgment mechanism signal vm and vk are generated to device, driving circuit generates driving capability by multiple driving mechanism
One group of strong reversed each other drive signal vm and vk；
Transmission gate circuit is the switch selection circuit being made of two pairs of PMOS tube and NMOS tube transmission gate, including NMOS tube
MS1, PMOS tube MS2, PMOS tube MS3 and NMOS tube MS4, NMOS tube MS1, the drain electrode of NMOS tube MS4 and PMOS tube MS2, NMOS
The source level of pipe MS4 meets the grid vg of NMOS tube N7, and the drain electrode of the source level and PMOS tube MS2 of NMOS tube MS1 connects the grid of NMOS tube N8
The drain electrode of pole vh, PMOS tube MS3 and the source level of NMOS tube MS4 meet the grid vi, NMOS tube MS1 of NMOS tube N9 and NMOS tube N10
The grid that judgment mechanism control signal vm, PMOS tube MS3 and NMOS tube MS4 are met with the grid of PMOS tube MS3 connects judgment mechanism control
Signal vk processed.
When judging that signal vm is high level, vk is low level, the transmission gate conducting of MS1 and MS2 compositions, MS3 and MS4 groups
End at transmission gate, vh is equal to vg, and vi is close to 0.The MS1 and MS2 compositions when judging that signal vm is low level, vk is high level
Transmission gate cut-off, the transmission gate conducting of MS3 and MS4 compositions, vi is equal to vg, and vh is close to 0.
Using inductive current size judgment mechanism circuit, due to flowing through the electric current of power switch tube and opening for the Switching Power Supply
Artis voltage Vsw is linear, so by detection switch node voltage Vsw, allows itself and preset reference voltage V ref
It is compared by comparing device, using drive signal, to obtain circuit operating pattern control signal vk and vm.By vk and vm
Controlling transmission gates current selecting circuit processed and is operated in big inductive current pattern or small inductor current-mode.
Compared with prior art, the advantageous effect of technical solution of the present invention is：The present invention discloses a kind of efficient inductive current
Detection circuit, including sequentially connected inductive current size judgment mechanism circuit, big inductive current detection circuit and current mirror electricity
Road further includes the small inductor current detection circuit in parallel with big inductive current detection circuit；Inductive current size judgment mechanism electricity
Road is used to judge to flow through the magnitude relationship of the size and preset critical value of the electric current of inductance, and exports judgment mechanism signal；From
And big inductive current detection circuit or small inductor current detection circuit is selected to be detected inductive current.It is disclosed by the invention
Inductive current circuit be suitable for BOOST DC-DC converters inductive current circuit, not only can with the big inductive current of efficient detection,
Extremely low inductive current can also be effectively detected, in large load current, inductive current is pressed into N times of scale smaller；Small
Width presses N/2 scale smallers under current conditions, by inductive current.To improve the accuracy of output end detection well.
Description of the drawings
Fig. 1 is the inductive current detection circuit figure for being the BOOST Switching Power Supplies for using Controlled in Current Mode and Based in the prior art.
Fig. 2 is inductive current detection structure block diagram of the present invention.
Fig. 3 is inductive current detection circuit schematic diagram of the present invention.
Specific implementation mode
The attached figures are only used for illustrative purposes and cannot be understood as limitating the patent；To those skilled in the art,
The omitting of some known structures and their instructions in the attached drawings are understandable.
The following further describes the technical solution of the present invention with reference to the accompanying drawings and examples.
Embodiment 1
Fig. 3 is inductive current detection circuit schematic diagram of the present invention, as shown in figure 3, a kind of efficient inductive current detection circuit,
Including sequentially connected inductive current size judgment mechanism circuit, big inductive current detection circuit and the first current mirroring circuit, also
Include the small inductor current detection circuit in parallel with big inductive current detection circuit；
Inductive current size judgment mechanism circuit, the size and preset critical value of the electric current for judging to flow through inductance
Magnitude relationship, and export judgment mechanism signal；
Big inductive current detection circuit, for detect inductive current it is bigger when flow through the current signal of inductance；
Small inductor current detection circuit, for detect inductive current it is smaller when flow through the current signal of inductance；
First current mirroring circuit, it is preset in the constant current equal with reference current and judgment mechanism circuit for generating
Reference voltage value.
The inductive current size judges testing mechanism circuit, with reference voltage V ref and node voltage Vsw into
Row compares, and to obtain control signal in comparator output terminal, obtains being directly used in control using driving circuit and phase inverter
Control the signal vk and vm of operating mode control the closure of two pairs of transmission gates.
For BOOST DC-DC Switching Power Supplies, during switching tube is connected, inductance is in the charging stage, power input,
Inductance and power switch tube form a circuit, for the NMOS switch pipe that a breadth length ratio determines, when it is operated in depth line
When property area, conducting resistance is：
So constant in drive signal, conducting resistance is a steady state value.So flow through switching tube electric current and
The drain-source current of switching tube is linearly, it is possible to pass through the section of drain voltage, that is, Switching Power Supply of detection switch pipe
It is relatively bigger than normal or less than normal that inductive current and preset inductive current are flowed through in the sw judgements of point voltage.
With reference to Fig. 3, inductive current size of the present invention judges that testing mechanism circuit includes to generate to preset inductance electricity
The circuit of stream critical value, comparator COM, driving circuit Driver, reverser, the transmission gate being made of MS1, MS2, MS3, MS4
Circuit.
The circuit of critical current mode value is preset in the generation, by current mirror P4, P2 and is operated in linear zone
NMOS tube Nref generates node voltage matched reference voltage V ref corresponding with default inductive current, and Nref tube grids connect
Input voltage VCC, is operated in linear zone, whereinAndSo
IP2=lIbias (3)
Presetting small inductor electric current is IL0, at this time by：
Vref=RNref*IP2=RMN*IL0 (4)
There are (2) (3) (4) can obtain：
K*l=IL0 (5)
So the respective breadth length ratio of PMOS tube P2 and NMOS tube Nref can be set according to formula (5).In two metal-oxide-semiconductors
Breadth length ratio has determined that the default inductor current value I of this circuit after determiningL0。
When inductive current is more than default inductive current IL0When, i.e. Vref<Sw, the vn of comparator output at this time is high level 1, then
Through overdrive circuit and negater circuit, obtain two controls signal vk=0 and vm=1, thus MS1 and MS2 transmission gates open,
MS3 and MS4 transmission gates are closed, so that the grid potential of grid potential vg, N9 and the N10 of the grid potential vh of N8 equal to N7
Vi is approximately equal to 0, so N8 and NB is opened, N9 and N10 are closed, settingThen flow through the electric current etc. of N8 pipes
In
Further, the big inductive current detection circuit includes three groups of NMOS tubes for being operated in depth linear zone, containing negative
The total grid grade amplifying circuit of feedback, the second current mirroring circuit, the electric current summation circuit formed by NMOS tube N7 and NMOS tube N8.
The total grid grade amplifying circuit containing negative-feedback includes the total grid grade amplifying circuit being made of P0, P1, N3 and N4
With the negative feedback loop formed by P7, N5, N3.Since the effect of negative-feedback makes the source level current potential of two input terminal N3 of amplifier
The source level current potential vd of vc and N4 is equal, i.e. vc=vd.
Three groups of NMOS tubes for being operated in depth linear zone, one group of NMOS tube are N1 and N2, and a drain electrode connects N5's
Source level, grid meet judgment mechanism signal vm, and a drain electrode connects the source level of N6, and grid meets judgment mechanism signal vm.Due to vm=1,
So being all operated in depth linear zone and IN1=IN2；Second group of NMOS tube is N5 and N6, and grid all connects the driving letter of power tube Mn
Number drive signal CLKN.Setting
R can be obtainedMN：RN1：RN2：RN5：RN6：RNB=1：2：2：2：2：2：2N (8)
Again by：
IN2*RN2+IN6*RN6=IL*RMN (9)
IN2=IN6+Ibias (10)
The electric current that N2 and N6 can must be flowed through by (8) (9) (10) is：WithFlow through N3
It is equal with the electric current of N4 and be Ibias, while it is equal to flow through N1 and N2 electric currents, is known by KCL so to flow through N5 and N6 electric currents equal,
I.e.：
Since N5 and N6 are operated in, linear zone, drain-source grade electric current be equal and vc=vd, so the drain potential of N5 is equal to N6
Drain potential, i.e. ve=sw.Third group is power switch tube Mn and NB, and a drain electrode connects the drain electrode of N6, and grid connects driving letter
Number CLKN, one drains and connects the drain electrode of N5, and grid meets the judgment mechanism signal vm obtained by inductive current size judgment mechanism circuit,
Due to ve=sw, so the drain voltage of Mn and MB is equal, the size of current relationship for then flowing through Mn and MB is：
The electric current summation circuit, which adds up the drain current for flowing through MB, N5 and N8, obtains required inductance detection electricity
Stream, the electric current that P6 pipes must be flowed through by (6) (12) (13) are：
The current-mirror structure being made of P5 and P6 makes, flows through the drain current of P5, i.e. sample rate current：
When inductive current is less than default inductive current IL0When, i.e. Vref>Sw, the vn of comparator output at this time is high level 0, then
Through overdrive circuit and negater circuit, obtain two controls signal vk=1 and vm=0, thus MS1 and MS2 transmission gates close,
MS3 and MS4 transmission gates are opened, so that the grid potential vh of N8 is approximately equal to the grid potential vi of 0, N9 and N10 equal to N7's
Grid potential vg, so N1, N2 and N8 are closed, N9 and N10 are opened and be operated in saturation region, further as the width of N9 and N10
Length is more consistent than with N7, ignores the drain current of channel modulation effect, N9 and N10 by current mirror mirror image N7, i.e.,：
IN9=IN10=Ibias (16)
Further, the small inductor current detection circuit includes two groups of NMOS tubes for being operated in depth linear zone, containing negative
Total grid grade amplifying circuit, the two groups of third current mirroring circuits of feedback.
The same with big inductive current, the total grid grade amplifying circuit containing negative-feedback includes being made of P0, P1, N3 and N4
Total grid grade amplifying circuit and the negative feedback loop that is formed by P7, N5, N3.Since the effect of negative-feedback makes two, amplifier defeated
Enter to hold the source level current potential vc of source level the current potential vc and N4 of N3 equal, i.e. vc=vd.
Two groups of NMOS tubes for being operated in depth linear zone, one group of NMOS tube are N5 and N6, and grid all connects the drive of power tube Mn
Dynamic signal drive signal CLKN.Due to IN3=IN4=IN9=IN10=Ibias, known according to KCL：Flow through the electric current of N5 and N6 all etc.
In 0, but it is all operated in depth linear zone, so the drain potential of N5 and the drain potential of N6 are all electric with respective source level at this time
Equal, the i.e. ve=sw=vc=vd in position；Second group of group is power switch tube Mn and ML, and a drain electrode connects the drain electrode of N6, and grid connects
Drive signal CLKN, a drain electrode connect the drain electrode of N5, and grid connects the judgment mechanism obtained by inductive current size judgment mechanism circuit
Signal vk, settingSince the drain voltage of vk=1 and Mn and ML are equal, so flowing through Mn's and ML
Size of current relationship is：
The electric current summation circuit, which adds up the drain current for flowing through NL, N5 and N8, obtains required inductance detection electricity
Stream, the electric current that must flow through P6 pipes are：
In conclusion the present invention is big using the inductive current at inductive current size judgment mechanism circuit judges transient state moment
Electric current or low current, and then detection pattern is selected, when inductive current is more than pre-set current value, circuit is operated in big inductive current
Detection pattern, obtained detection electric current is inductive currentTimes；When inductive current is low current, circuit is operated in small inductor electricity
Detection pattern is flowed, obtained detection electric current is inductive currentSince two inductive current detection patterns do not work at the same time, have
Control to effect the power consumption of circuit.The present invention not only solves load too low in traditional inductance current detecting and leads to inductive current
Non-detectable problem also solves the accuracy of detection the problem of, inductive current peak is accurately had detected, so that the electricity
It is effectively applied in the BOOST DC-DC Switching Power Supplies of Controlled in Current Mode and Based on road.
The above embodiment of the present invention be only to clearly illustrate example of the present invention, and not be to the present invention
Embodiment restriction.For those of ordinary skill in the art, it can also make on the basis of the above description
Other various forms of variations or variation.There is no necessity and possibility to exhaust all the enbodiments.It is all the present invention
All any modification, equivalent and improvement etc., should be included in the protection of the claims in the present invention made by within spirit and principle
Within the scope of.
Claims (4)
1. a kind of efficient inductive current detection circuit, which is characterized in that the inductive current detection circuit includes being sequentially connected
Inductive current size judgment mechanism circuit, big inductive current detection circuit and the first current mirroring circuit, further include and big inductance
The small inductor current detection circuit of current detection circuit parallel connection；
Inductive current size judgment mechanism circuit, the size of the size and preset critical value of the electric current for judging to flow through inductance
Relationship, and export judgment mechanism signal；
Big inductive current detection circuit, for detect inductive current it is bigger when flow through the current signal of inductance；
Small inductor current detection circuit, for detect inductive current it is smaller when flow through the current signal of inductance；
First current mirroring circuit, for generating preset benchmark in the constant current equal with reference current and judgment mechanism circuit
Voltage value；
The big inductive current detection circuit includes three groups of NMOS tubes for being operated in depth linear zone, the total grid grade containing negative-feedback
Amplifying circuit, the second current mirroring circuit, the electric current summation circuit formed by NMOS tube N7 and NMOS tube N8；
Three groups are operated in the NMOS tube of depth linear zone, and first group of NMOS tube is NMOS tube N5 and NMOS tube N6, NMOS tube N5
Drive signal CLKN is met with the grid of NMOS tube N6；Second group of NMOS tube is power switch tube MP and NB, and the drain electrode of MP meets NMOS
The drain electrode of pipe N6, the drain electrode that the grid of MP meets drive signal CLKP, NB connect the drain electrode of NMOS tube N5, the source electrode ground connection of NB, NB's
Grid meets the judgment mechanism signal vm of inductive current size judgment mechanism circuit output；Third group NMOS tube be NMOS tube N1 and
NMOS tube N2, NMOS tube N1 are connected with the grid of NMOS tube N2, and the drain electrode of NMOS tube N1 meets the source level of NMOS tube N5, NMOS tube N1
Source electrode ground connection, the drain electrode that the grid of NMOS tube N1 meets judgment mechanism signal vm, NMOS tube N2 meets the source level of NMOS tube N6, NMOS
The source electrode of pipe N2 is grounded, and the grid of NMOS tube N2 meets judgment mechanism signal vm；
Total grid grade amplifying circuit containing negative-feedback includes being made of PMOS tube P0, PMOS tube P1 and NMOS tube N3, NMOS tube N4
Grid grade amplifying circuit and the negative feedback loop being made of PMOS tube P7 and NMOS tube N5, NMOS tube N3 altogether；PMOS tube P0, PMOS
The grid of pipe P1 connects, PMOS tube P0, PMOS tube P1 source electrode connect power supply, the drain electrode of PMOS tube P0 connects the drain electrode of NMOS tube N3,
The drain electrode of PMOS tube P1 connects the drain electrode of NMOS tube N4, and the grid of NMOS tube N3 is connected with the grid of NMOS tube N4, drain electrode, NMOS tube
The source electrode of N3 is connect with the drain electrode of NMOS tube N1, and the source electrode of NMOS tube N4 is connect with the drain electrode of NMOS tube N2；The grid of PMOS tube P7
Pole connects the drain electrode of NMOS tube N3, and the drain electrode of PMOS tube P7 connects the drain electrode of NMOS tube N5；
Second current mirroring circuit includes NMOS tube N7, NMOS tube N8, the drain and gate connection of NMOS tube N7, the source of NMOS tube N7
Pole is grounded, and the drain electrode of NMOS tube N8 connects the source electrode of PMOS tube P7, the source electrode ground connection of NMOS tube N8；Flow through the electric current of NMOS tube N8 with
Reference current is proportional；
The drain current for flowing through NB, NMOS tube N5 and NMOS tube N8 is added up and obtains required electricity by the electric current summation circuit
Sense detection electric current.
2. efficient inductive current detection circuit according to claim 1, which is characterized in that the small inductor current detecting
Circuit includes two groups of NMOS tubes for being operated in depth linear zone, total grid grade amplifying circuit, two groups of third current mirrors containing negative-feedback
Circuit；
Two groups of NMOS tubes for being operated in depth linear zone, first group is power switch tube MP and NL, and the drain electrode of NL meets NMOS tube N5
Drain electrode, the grid of NL meets the judgment mechanism signal vk of inductive current size judgment mechanism circuit output；Second group of NMOS tube be
The grid of NMOS tube N5 and NMOS tube N6, NMOS tube N5 and NMOS tube N6 all meet drive signal CLKN；
Total grid grade amplifying circuit containing negative-feedback includes being made of PMOS tube P0, PMOS tube P1 and NMOS tube N3, NMOS tube N4
Grid grade amplifying circuit and the negative feedback loop being made of PMOS tube P7 and NMOS tube N5, NMOS tube N3 altogether；
In two groups of third current mirroring circuits, one of which is made of NMOS tube N7 and NMOS tube N9, another group by NMOS tube N7 and
NMOS tube N10 compositions, the electric current for obtaining flowing through NMOS tube N9 and NMOS tube N10 by current mirror are equal with reference current.
3. efficient inductive current detection circuit according to claim 1, which is characterized in that first current mirroring circuit
Further include reference current source IBIAS and PMOS tube P0, PMOS tube P1, PMOS tube P3, PMOS tube P4, PMOS tube P5, PMOS tube P6；
PMOS tube P3 is connected with the grid of PMOS tube P4, and the source electrode of PMOS tube P3 and PMOS tube P4 connect power supply, the leakage of PMOS tube P3
Pole connects the drain electrode of NMOS tube N7, the drain and gate connection of PMOS tube P4, and the drain electrode of PMOS tube P4 connects reference current source IBIAS's
One end, the other end ground connection of reference current source IBIAS；The drain electrode of PMOS tube P5 and PMOS tube P6 connect power supply, PMOS tube P5 and
The grid of PMOS tube P6 connects, after the grid of PMOS tube P6 after source electrode connection also respectively with the drain electrode of NMOS tube N8 and PMOS tube P7
Source electrode connection.
4. efficient inductive current detection circuit according to claim 1, which is characterized in that the inductive current size is sentenced
Disconnected scheme circuitry include generate the circuit for presetting critical current mode value, comparator COM, driving circuit Driver, reverser, with
And transmission gate circuit；
The circuit of critical current mode value is preset in the described generation, the current mirror by being made of PMOS tube P4, PMOS tube P2 and
The NMOS tube Nref for being operated in linear zone generates the matched reference voltage of node voltage corresponding with default inductive current
The grid of Vref, Nref connect power supply, are operated in linear zone, and the source electrode of PMOS tube P2 connects power supply, the grid of PMOS tube P2 respectively with
The grid connection of PMOS tube P0, PMOS tube P1, PMOS tube P3, PMOS tube P4, the source electrode ground connection of Nref, the grid of Nref connect electricity
Source, the drain electrode connection of PMOS tube P2 and Nref are followed by the reverse input end of comparator COM；
Comparator COM positive inputs connect the switching node sw of BOOST Switching Power Supplies, i.e. the drain electrode Vsw of MN pipes, reverse input end
Meet preset reference voltage V ref, the input terminal vn of output termination driving circuit Driver；Driving circuit Driver and reverser
Inductive current size judgment mechanism signal vm and vk are generated, it is strong to generate driving capability by multiple driving mechanism for driving circuit
One group of reversed each other drive signal vm and vk；
Transmission gate circuit is the switch selection circuit being made of two pairs of PMOS tube and NMOS tube transmission gate, including NMOS tube MS1,
PMOS tube MS2, PMOS tube MS3 and NMOS tube MS4, NMOS tube MS1, the drain electrode of NMOS tube MS4 and PMOS tube MS2, NMOS tube MS4
Source level meet the grid vg of NMOS tube N7, the drain electrode of the source level and PMOS tube MS2 of NMOS tube MS1 meets the grid vh of NMOS tube N8,
The drain electrode of PMOS tube MS3 and the source level of NMOS tube MS4 meet the grid vi of NMOS tube N9 and NMOS tube N10, NMOS tube MS1 and PMOS
The grid that the grid of pipe MS3 meets judgment mechanism control signal vm, PMOS tube MS3 and NMOS tube MS4 connects judgment mechanism control signal
vk。
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| CN108169592B (en) * | 2017-12-15 | 2023-11-24 | 西安智财全技术转移中心有限公司 | Intelligent detection circuit and intelligent detection method |
| CN108226609B (en) * | 2017-12-27 | 2020-02-07 | 上海贝岭股份有限公司 | Current detection circuit for DC-DC converter |
| CN114167125B (en) * | 2021-07-29 | 2023-12-12 | 沈阳工业大学 | Current detection circuit |
| CN117289012B (en) * | 2023-11-24 | 2024-02-13 | 浙江森尼克半导体有限公司 | Dual-current input/output, dual-isolation current sensor and current detection method |
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