CN109962682A - A kind of pseudo-differential copped wave instrument amplifier and its ECG signal monitor front-end chip - Google Patents

A kind of pseudo-differential copped wave instrument amplifier and its ECG signal monitor front-end chip Download PDF

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Publication number
CN109962682A
CN109962682A CN201910130707.7A CN201910130707A CN109962682A CN 109962682 A CN109962682 A CN 109962682A CN 201910130707 A CN201910130707 A CN 201910130707A CN 109962682 A CN109962682 A CN 109962682A
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China
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switch
capacitor
circuit
ecg signal
copped wave
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CN201910130707.7A
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Inventor
朱樟明
张程高
刘术彬
丁瑞雪
杨银堂
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Xidian University
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Xidian University
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Priority to CN201910130707.7A priority Critical patent/CN109962682A/en
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    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/24—Detecting, measuring or recording bioelectric or biomagnetic signals of the body or parts thereof
    • A61B5/316—Modalities, i.e. specific diagnostic methods
    • A61B5/318—Heart-related electrical modalities, e.g. electrocardiography [ECG]
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F1/00—Details of amplifiers with only discharge tubes, only semiconductor devices or only unspecified devices as amplifying elements
    • H03F1/26—Modifications of amplifiers to reduce influence of noise generated by amplifying elements
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F3/00—Amplifiers with only discharge tubes or only semiconductor devices as amplifying elements
    • H03F3/38—Dc amplifiers with modulator at input and demodulator at output; Modulators or demodulators specially adapted for use in such amplifiers
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F3/00—Amplifiers with only discharge tubes or only semiconductor devices as amplifying elements
    • H03F3/68—Combinations of amplifiers, e.g. multi-channel amplifiers for stereophonics
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F2200/00—Indexing scheme relating to amplifiers
    • H03F2200/372—Noise reduction and elimination in amplifier

Abstract

The present invention relates to a kind of pseudo-differential copped wave instrument amplifiers and its ECG signal to monitor front-end chip, the pseudo-differential copped wave instrument amplifier includes: first order copped wave artifact parallel circuit, second level magnifier, wherein, the first order copped wave artifact parallel circuit, ECG signal for the input terminal input to the first order copped wave artifact parallel circuit carries out first time chopping modulation and enhanced processing, obtains the first ECG signal；The second level magnifier, connect the first order copped wave artifact parallel circuit, for carrying out second of chopping modulation and enhanced processing to first ECG signal, obtaining the second ECG signal and exporting second ECG signal from the output end of the second level magnifier.Present invention employs pseudo-differential copped wave instrument amplifiers, and which reduce the areas of ECG signal monitoring front-end chip, reduce the power consumption of chip, and more convenient wearable, portable ECG monitors systematic difference.

Description

A kind of pseudo-differential copped wave instrument amplifier and its ECG signal monitor front-end chip
Technical field
The invention belongs to medical sciences, and in particular to a kind of pseudo-differential copped wave instrument amplifier and its ECG signal prison Survey front-end chip.
Background technique
Root according to the statistics of the World Health Organization, the 30% of the total death toll of number Zhan dead due to cardiovascular disease now, Cardiovascular disease has become the first big threat of human health, and wants care diagnostic cardiovascular disease, detects the heart for a long time Electrograph (Electrocardiogram, abbreviation ECG) signal is most practical, feasible method.
In the past few decades, more and more people begin to focus on high reliability, low-power consumption, wearable ECG monitoring simulation Front-end chip.ECG monitoring analog front-end chip be for for a long time, the core chips of continuous measurement ECG signal system, it is this just Take formula ECG monitoring system it is very big facilitate the Disease far away from each corner.
But that there are amplification factors is small for existing commercialization ECG analog front-end chip, the high problem of power consumption is unfavorable for wear It wears, portable ECG monitoring systematic difference.
Summary of the invention
In order to solve the above-mentioned problems in the prior art, the present invention provides a kind of pseudo-differential copped wave instrument amplifiers And its ECG signal monitors front-end chip.The embodiment of the invention provides a kind of pseudo-differential copped wave instrument amplifier, the amplifier packets It includes:
First order copped wave artifact parallel circuit, second level magnifier, wherein
The first order copped wave artifact parallel circuit, for the input terminal input to the first order copped wave artifact parallel circuit ECG signal carries out first time chopping modulation and enhanced processing, obtains the first ECG signal；
The second level magnifier connects the first order copped wave artifact parallel circuit, for the first ECG Signal carries out second of chopping modulation and enhanced processing, obtains the second ECG signal and from the second level magnifier Output end exports second ECG signal.
In one embodiment of the invention, the first order copped wave artifact parallel circuit includes modulation unit, negative capacitance electricity Road, first order gain amplifying circuit, wherein
The modulation unit obtains the first modulation ECG signal for carrying out chopping modulation processing to the ECG signal；
The negative capacitance circuit connects the modulation unit, for reducing the decaying of the first modulation ECG signal；
The first order gain amplifying circuit connects the modulation unit, the negative capacitance circuit, for described first Modulation ECG signal amplifies processing, obtains first ECG signal.
In one embodiment of the invention, the negative capacitance circuit includes transistor M1, transistor M2, transistor M3, it is brilliant Body pipe M4, transistor M5, capacitance group Cc1, capacitance group Cc2, wherein
The transistor M1Grid and the first order gain amplifying circuit 103, the capacitance group Cc2One end connection, institute State transistor M1Drain electrode and the capacitance group Cc1One end, the transistor M3Drain electrode connection, the transistor M1Source electrode with The transistor M5Drain electrode, the transistor M2Source electrode connection, the transistor M2Grid put with first stage gain Big circuit 103, the capacitance group Cc1The other end, the transistor M2Drain electrode and the capacitance group Cc2The other end, the crystal Pipe M4Drain electrode connection, the transistor M3Grid and the transistor M4Grid connection, the transistor M3Source electrode, The transistor M4Source electrode in power vd D connection, the transistor M5Grid connect with bias voltage VB, the crystal Pipe M5Source electrode ground connection.
In one embodiment of the invention, the capacitance group Cc1, the capacitance group Cc2Structure is identical, the capacitance group Cc1, the capacitance group Cc2It include several switching capacity groups, wherein
The capacitance group Cc1In several switching capacity groups it is in parallel, and the switching capacity group is serially connected with transistor M1Drain electrode and described with transistor M2Grid；
The capacitance group Cc2In several switching capacity groups it is in parallel, and the switching capacity group is serially connected with transistor M2 Drain electrode and transistor M1Grid；
Each switching capacity group includes 1 capacitor and 2 switches, and the capacitance series are between the switch.
In one embodiment of the invention, the second level magnifier includes blocking biasing circuit, the second level Copped wave operational amplification circuit, the first feedback loop, second feed back loop, Ripple Suppression circuit, wherein
The blocking biasing circuit (201), connects the first order gain amplifying circuit, for believing the first ECG Number carry out blocking processing；
Copped wave operational amplification circuit in the second level connects the blocking biasing circuit, the signal output end, for described The first ECG signal after blocking is amplified to be handled with chopping modulation, obtains the second modulation ECG signal；
First feedback loop connects the second level copped wave operational amplification circuit, is used for the second level copped wave Direct current signal in the second modulation ECG signal of operational amplification circuit output feeds back to the second level copped wave operation amplifier Circuit；
The Ripple Suppression circuit connects the second level copped wave operational amplification circuit, is used for the second level copped wave Ripple signal in the second modulation ECG signal of operational amplification circuit output feeds back to second level copped wave operation amplifier electricity Road；
The second feed back loop connects the second level copped wave operational amplification circuit, is used for the second level copped wave The second modulation ECG signal of operational amplification circuit output feeds back to second level copped wave operational amplification circuit；
The second level copped wave operational amplification circuit be also used to handle it is described second modulation ECG signal, the direct current signal, The ripple signal obtains second ECG signal.
In one embodiment of the invention, second level copped wave operational amplification circuit (202) includes difference amplifier GM1、 Chopping modulation device CH3, difference amplifier GM2, capacitor Cm1With capacitor Cm2, wherein
The difference amplifier GM1Input terminal and the blocking biasing circuit, first feedback loop, described second are instead It is fed back to road connection, the difference amplifier GM1Output end and the chopping modulation device CH3Input terminal, the Ripple Suppression circuit connect It connects, the chopping modulation device CH3Output end and the difference amplifier GM2Input terminal, the capacitor Cm1One end, the capacitor Cm2 One end connection, the difference amplifier GM2Output end and the capacitor Cm1The other end, the capacitor Cm2The other end, described first Feedback loop, the second feed back loop, Ripple Suppression circuit connection.
In one embodiment of the invention, the Ripple Suppression circuit includes difference amplifier GM3, integrator Int2, cut Wave modulator CH4, capacitor Cint1, capacitor Cint2, capacitor CS1, capacitor CS2, wherein
The capacitor CS1One end and the difference amplifier GM2Positive output end, the capacitor Cm1One end connection, the electricity Hold CS1The other end and the chopping modulation device CH4First input end connection, the capacitor CS2One end and the difference amplifier GM2Reversed-phase output, the capacitor Cm2One end connection, the capacitor CS2The other end and the chopping modulation device CH4It is second defeated Enter end connection, the chopping modulation device CH4The first output end and the capacitor Cint1One end, the integrator Int2First Input terminal connection, the chopping modulation device CH4Second output terminal and the capacitor Cint2One end, the integrator Int2? The connection of two input terminals, the integrator Int2The first output end and the capacitor Cint2The other end, the capacitor Cint1It is another End, the difference amplifier GM3Input terminal connection, the difference amplifier GM3Positive output end and the chopping modulation device CH3 The second input terminal, the difference amplifier GM1Reversed-phase output connection, the difference amplifier GM3Reversed-phase output with it is described Chopping modulation device CH3First input end, the difference amplifier GM1Positive output end connection.
In one embodiment of the invention, the integrator Int2For Ping-Pong integrator, the Ping-Pong Integrator includes Ping structural circuit and Pong structural circuit, wherein
The Ping structural circuit includes switch S1, switch S2, switch S3, switch S4, switch S5, switch S6, switch S7, open Close S8, capacitor Cset1, capacitor Cset2, difference amplifier GM4, the switch S1One end and the chopping modulation device CH4It is first defeated Outlet, the capacitor Cint1One end connection, the switch S1The other end and the switch S3One end, the capacitor Cset1One end connects It connects, the capacitor Cset1The other end and the switch S5One end, the difference amplifier GM4Normal phase input end connection, the switch S5The other end and the difference amplifier GM4Reversed-phase output, the switch S7One end connection, the switch S7The other end and institute State capacitor Cint1The other end, the difference amplifier GM3Normal phase input end connection, the switch S2One end and the chopping modulation Device CH4Second output terminal, the capacitor Cint2One end connection, the switch S2The other end and the switch S4One end, the electricity Hold Cset2One end connection, the capacitor Cset2The other end and the switch S6One end, the difference amplifier GM4Inverting input terminal Connection, the switch S6The other end and the difference amplifier GM4Positive output end, the switch S8One end connection, the switch S8The other end and the capacitor Cint2The other end, the difference amplifier GM3Inverting input terminal connection, the switch S3The other end With the switch S4The other end meets VCM；
The Pong structural circuit includes switch S9, switch S10, switch S11, switch S12, switch S13, switch S14, switch S15, switch S16, capacitor Cset3, capacitor Cset4, difference amplifier GM5, the switch S9One end and the chopping modulation device CH4's First output end, the capacitor Cint1One end connection, the switch S9The other end and the switch S11One end, the capacitor Cset3 One end connection, the capacitor Cset3The other end and the switch S13One end, the difference amplifier GM5Normal phase input end connection, The switch S13The other end and the difference amplifier GM5Reversed-phase output, the switch S15One end connection, the switch S15 The other end and the capacitor Cint1The other end, the difference amplifier GM3Normal phase input end connection, the switch S10One end and institute State chopping modulation device CH4Second output terminal, the capacitor Cint2One end connection, the switch S10The other end and the switch S12 One end, the capacitor Cset4One end connection, the capacitor Cset4The other end and the switch S14One end, the difference amplifier GM5 Inverting input terminal connection, the switch S14The other end and the difference amplifier GM5Positive output end, the switch S16One end connects It connects, the switch S16The other end and the capacitor Cint2The other end, the difference amplifier GM3Inverting input terminal connection, it is described Switch S11The other end and the switch S12The other end meets VCM。
Another embodiment of the present invention provides a kind of ECG signals to monitor front-end chip, which includes above-mentioned any One amplifier.
In one embodiment of the invention, the front-end chip further includes switch capacitor filter, Delta-Sigma tune Device processed, wherein
The switch capacitor filter connects the amplifier, the 2nd ECG letter for exporting the amplifier It number carries out filtering out noise processed, obtains third ECG signal；
The Delta-Sigma modulator, connects the switch capacitor filter, for the third ECG signal into Row analog-to-digital conversion process obtains the 4th ECG signal.
Compared with prior art, beneficial effects of the present invention:
1, present invention employs pseudo-differential copped wave instrument amplifier, which reduce the area of ECG signal monitoring front-end chip, The power consumption of chip is reduced, more convenient wearable, portable ECG monitors systematic difference.
2, present invention employs negative capacitance circuits, improve the equivalent input impedance of ECG signal monitoring front-end chip circuits.
3, present invention employs chopping modulation technology, reduced in ECG signal monitoring front-end chip circuits 1/f noise with And interference of the DC offset voltage to ECG signal.
4, present invention employs the Ripple Suppression circuits with Ping-Pong structure, before effectively inhibiting ECG signal to monitor The high frequency ripple that end chip circuit is generated due to chopping modulation, and prevent the generation of secondary ripple wave.
Detailed description of the invention
Fig. 1 is a kind of structural schematic diagram of pseudo-differential copped wave instrument amplifier provided in an embodiment of the present invention；
Fig. 2 is the structural schematic diagram of another pseudo-differential copped wave instrument amplifier provided in an embodiment of the present invention；
Fig. 3 is the structural schematic diagram of another pseudo-differential copped wave instrument amplifier provided in an embodiment of the present invention；
Fig. 4 is negative capacitance circuit schematic diagram in a kind of pseudo-differential copped wave instrument amplifier provided in an embodiment of the present invention；
Fig. 5 is input impedance provided in an embodiment of the present invention with capacitance group Cc1, capacitance group Cc2The schematic diagram of structure change；
Fig. 6 is Ripple Suppression loop circuit signal in a kind of pseudo-differential copped wave instrument amplifier provided in an embodiment of the present invention Figure；
Fig. 7 is the structural schematic diagram that a kind of ECG signal provided in an embodiment of the present invention monitors front-end chip；
Fig. 8 is the circuit that a kind of ECG signal provided in an embodiment of the present invention monitors switch capacitor filter in front-end chip Schematic diagram；
Fig. 9 is the electricity that a kind of ECG signal provided in an embodiment of the present invention monitors Delta-Sigma modulator in front-end chip Road schematic diagram；
Figure 10 is the equivalent input noise result of spectrum analysis that ECG signal provided in an embodiment of the present invention monitors front-end chip Schematic diagram；
Figure 11 is the entire gain response results schematic diagram that ECG signal provided in an embodiment of the present invention monitors front-end chip；
Figure 12 is the SDM measured power spectral density result that ECG signal provided in an embodiment of the present invention monitors front-end chip Schematic diagram；
Figure 13 is test SNR and the SNDR result schematic diagram that ECG signal provided in an embodiment of the present invention monitors front-end chip；
Figure 14 is the experimental result schematic diagram of ECG signal provided in an embodiment of the present invention measurement.
Description of symbols:
Pseudo-differential copped wave instrument amplifier 1；Switch capacitor filter 2；Delta-Sigma modulator 3；First order copped wave is pseudo- Difference channel 10；Second level magnifier 20；Modulation unit 101；Negative capacitance circuit 102；First order gain amplifying circuit 103；Blocking biasing circuit 201；Second level copped wave operational amplification circuit 202；First feedback loop 203；Second feed back loop 204；Ripple Suppression circuit 205；Ping structural circuit 2051；Pong structural circuit 2052.
Specific embodiment
Further detailed description is done to the present invention combined with specific embodiments below, but embodiments of the present invention are not limited to This.
Embodiment 1:
Referring to Figure 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6, Fig. 1 are a kind of pseudo-differential copped wave instrument provided in an embodiment of the present invention The structural schematic diagram of table amplifier；Fig. 2 is the structure of another pseudo-differential copped wave instrument amplifier provided in an embodiment of the present invention Schematic diagram；Fig. 3 is the structural schematic diagram of another pseudo-differential copped wave instrument amplifier provided in an embodiment of the present invention；Fig. 4 is this Negative capacitance circuit schematic diagram in a kind of pseudo-differential copped wave instrument amplifier that inventive embodiments provide；Fig. 5 is the embodiment of the present invention The input impedance of offer is with capacitance group Cc1, capacitance group Cc2The schematic diagram of structure change；Fig. 6 is provided in an embodiment of the present invention one Ripple Suppression loop circuit schematic diagram in kind pseudo-differential copped wave instrument amplifier.A kind of pseudo-differential provided in an embodiment of the present invention is cut The circuit structure of wave instrument amplifier, the pseudo-differential copped wave instrument amplifier 1 includes:
First order copped wave artifact parallel circuit 10, second level magnifier 20, wherein
First order copped wave artifact parallel circuit 10, the ECG letter for being inputted to 10 input terminal of first order copped wave artifact parallel circuit Number first time chopping modulation and enhanced processing are carried out, obtains the first ECG signal；
Second level magnifier 20 connects first order copped wave artifact parallel circuit 10, for carrying out to the first ECG signal Second of chopping modulation and enhanced processing obtain the second ECG signal and from 20 output end of second level magnifier output the Two ECG signals.
Further, first order copped wave artifact parallel circuit 10 includes modulation unit 101, negative capacitance circuit 102, first order increasing Beneficial amplifying circuit 103, wherein
Modulation unit 101 obtains the first modulation ECG signal for carrying out chopping modulation processing to ECG signal；
Negative capacitance circuit 102 connects modulation unit 101, for reducing the decaying of the first modulation ECG signal；
First order gain amplifying circuit 103 connects modulation unit 101, negative capacitance circuit 102, for the first modulation ECG Signal amplifies processing, obtains the first ECG signal.
Specifically, modulation unit 101 includes chopping modulation device CH1, chopping modulation device CH1Input terminal and signal input part VinConnection, chopping modulation device CH1The input terminal of output end and negative capacitance circuit 102, first order gain amplifying circuit 103 it is defeated Enter end connection.The present embodiment passes through chopping modulation device CH1To signal input part VinThe ECG signal of input carries out at chopping modulation Reason, is modulated to high frequency for the ECG signal of low frequency, obtains the first modulation ECG signal, in this way can be by first order copped wave pseudo-differential electricity The ECG signal of 10 input terminal of road input is separated with the circuit offset voltage at low frequency in circuit and 1/f noise.
Negative capacitance circuit 102, including transistor M1, transistor M2, transistor M3, transistor M4, transistor M5, capacitance group Cc1, capacitance group Cc2, connection relationship is above-mentioned have been described, and details are not described herein.
Preferably, transistor M1, transistor M2, transistor M5It is N-type metal-oxide-semiconductor, transistor M3, transistor M4It is p-type Metal-oxide-semiconductor.
Wherein, capacitance group Cc1, capacitance group Cc2Structure is identical, capacitance group Cc1, capacitance group Cc2It include several switching capacities Group, in capacitance group Cc1In several switching capacity groups it is in parallel, switching capacity group is serially connected with transistor M1Drain electrode and transistor M2Grid, capacitance group Cc2In several switching capacity groups it is in parallel, switching capacity group is serially connected with transistor M2Drain electrode and crystal Pipe M1Grid, each switching capacity group include 1 capacitor and 2 switch, capacitance series in 2 switch between.
Specifically, capacitance group C in the present embodimentc1With capacitance group Cc2Structure it is identical, include capacitor Cu1, capacitor Cu2, electricity Hold Cu3, capacitor Cu4, capacitor Cu5, capacitance group Cc1With capacitance group Cc2In switch include switch S11, switch S12, switch S13, open Close S14, switch S15, switch S21, switch S22, switch S23, switch S24, switch S25.Capacitor Cu1, switch S11, switch S21Composition one Group switching capacity group, capacitor Cu1It is serially connected with switch S11With switch S21Between, capacitance group Cc1Middle switch S11The other end and transistor M1 Drain electrode connection, switch S21The other end and transistor M2Grid connection, capacitance group Cc2Middle switch S11The other end and transistor M1 Grid connection, switch S21The other end and transistor M2Drain electrode connection；Capacitor Cu2, switch S12, switch S22Form one group of switch Capacitance group, capacitor Cu2It is serially connected with switch S12With switch S22Between, capacitance group Cc1Middle switch S12The other end and transistor M1Drain electrode Connection, switch S22The other end and transistor M2Grid connection, capacitance group Cc2Middle switch S12The other end and transistor M1Grid Connection, switch S22The other end and transistor M2Drain electrode connection；Capacitor Cu3, switch S13, switch S23Form one group of switching capacity Group, capacitor Cu3It is serially connected with switch S13With switch S23Between, capacitance group Cc1Middle switch S13The other end and transistor M1Drain electrode connect It connects, switch S23The other end and transistor M2Grid connection, capacitance group Cc2Middle switch S13The other end and transistor M1Grid connect It connects, switch S23The other end and transistor M2Drain electrode connection；Capacitor Cu4, switch S14, switch S24One group of switching capacity group is formed, Capacitor Cu4It is serially connected with switch S14With switch S24Between, capacitance group Cc1Middle switch S14The other end and transistor M1Drain electrode connection, open Close S24The other end and transistor M2Grid connection, capacitance group Cc2Middle switch S14The other end and transistor M1Grid connection, open Close S24The other end and transistor M2Drain electrode connection；Capacitor Cu5, switch S15, switch S25Form one group of switching capacity group, capacitor Cu5 Parallel connection is serially connected with switch S15With switch S25Between, capacitance group Cc1Middle switch S15The other end and transistor M1Drain electrode connection, switch S25The other end and transistor M2Grid connection, capacitance group Cc2Middle switch S15The other end and transistor M1Grid connection, switch S25The other end and transistor M2Drain electrode connection.By the 2nd ECG for judging the output of 1 output end of pseudo-differential copped wave instrument amplifier The amplitude information of signal, control switch S11, switch S12, switch S13, switch S14, switch S15, switch S21, switch S22, switch S23, switch S24, switch S25Closure and disconnection, to adjust the capacitance of negative capacitance circuit 102, and then eliminate pseudo-differential and cut The parasitic capacitance of 1 input terminal of wave instrument amplifier, obtains the input circuit of high input impedance.Due between bioelectrode and human body Impedance is very big, if 1 inlet circuit itself input impedance of pseudo-differential copped wave instrument amplifier is smaller, it will cause acquired The decaying of first modulation ECG signal.Therefore in order to reduce the decaying of the first of acquisition the modulation ECG signal, the present embodiment as far as possible Negative capacitance circuit 102 is added in circuit input end, and then improves the input impedance of circuit.Wherein, capacitor Cu1: capacitor Cu2: capacitor Cu3: capacitor Cu4: capacitor Cu5=1:2:4:8:16, in the present embodiment, capacitor Cu1For Cu, CuFor unit capacitor, then capacitor Cu2For 2Cu, capacitor Cu3For 4Cu, capacitor Cu4For 8Cu, capacitor Cu8For 16Cu。
Referring again to Fig. 5, abscissa is capacitance group C in figurec1, capacitance group Cc2The number of the specific capacitance of middle connection is indulged and is sat It is designated as the equivalent input impedance of ECG signal monitoring front-end chip circuits, it is seen then that with capacitance group Cc1, capacitance group Cc2Middle unit electricity The increase of the number of appearance, the equivalent input impedance of circuit first becomes larger to become smaller afterwards.In the present embodiment, when to take input impedance be maximum Capacitance group Cc1, capacitance group Cc2Structure, constitute negative capacitance circuit 102, for ECG signal monitoring front-end chip circuits provide it is high Equivalent input impedance.At the same time, as shown in Figure 5, the equivalent input impedance of negative capacitance circuit 102 can satisfy in the present embodiment The demand of the G Ω order of magnitude.
First order gain amplifying circuit 103 connects modulation unit 101, negative capacitance circuit 102, for the first modulation ECG Signal amplifies processing, obtains the first ECG signal
Specifically, first order gain amplifying circuit 103 includes amplifier IA1, amplifier IA2, capacitor C1, capacitor C2, capacitor C3, electricity Hold C4, resistance Rp1, resistance Rp2, resistance Rp3, resistance Rp4, wherein amplifier IA1Normal phase input end and resistance Rp1One end, modulation are single Chopping modulation device CH in member 1011The first output end, the transistor M in negative capacitance circuit 1021Grid connection, amplifier IA1 Inverting input terminal and capacitor C1One end, capacitor C3One end, resistance Rp3One end connection, amplifier IA1Output end and capacitor C1It is another End, resistance Rp3The input terminal connection of the other end, blocking biasing circuit 201, capacitor C3Other end ground connection, resistance Rp1The other end and electricity Hinder Rp2One end meets voltage VCM, resistance Rp2The other end and amplifier IA2Normal phase input end, modulation unit 101 chopping modulation device CH1Second output terminal, the transistor M in negative capacitance circuit 1022Grid connection, amplifier IA2Inverting input terminal and capacitor C2One end, capacitor C4One end, resistance Rp4One end connection, amplifier IA2Output end and capacitor C2The other end, resistance Rp4The other end, every The input terminal connection of straight biasing circuit 201, capacitor C4Other end ground connection.As it can be seen that the first of the output of 101 output end of modulation unit adjusts ECG signal processed passes through first order gain amplifying circuit 103, processing is exaggerated to the first modulation ECG signal, to obtain the One ECG signal, and negative capacitance circuit 102 reduces the decaying of ECG signal in the acquisition of the first ECG signal.
Further, second level magnifier 20 includes blocking biasing circuit 201, second level copped wave operation amplifier electricity Road 202, the first feedback loop 203, second feed back loop 204, Ripple Suppression circuit 205, wherein
Blocking biasing circuit 201 connects first order gain amplifying circuit 103, for carrying out at blocking to the first ECG signal Reason；
Second level copped wave operational amplification circuit 202 connects blocking biasing circuit 201, for believing the first ECG after blocking Number amplify with chopping modulation processing, obtain the second modulation ECG signal；
First feedback loop 203 connects second level copped wave operational amplification circuit 202, for putting second level copped wave operation The direct current signal in the second modulation ECG signal that big circuit 202 exports feeds back to second level copped wave operational amplification circuit 202；
Ripple Suppression circuit 205 connects second level copped wave operational amplification circuit 202, for putting second level copped wave operation The ripple signal in the second modulation ECG signal that big circuit 202 exports feeds back to second level copped wave operational amplification circuit 202；
Second feed back loop 204 connects second level copped wave operational amplification circuit 202, for putting second level copped wave operation The second modulation ECG signal that big circuit 202 exports feeds back to second level copped wave operational amplification circuit 202；
Second level copped wave operational amplification circuit 202 is also used to handle the second modulation ECG signal, direct current signal, ripple signal, Obtain the second ECG signal.
Specifically, blocking biasing circuit 201 includes capacitor Cin1, capacitor Cin1, resistance Rp5, resistance Rp6, wherein capacitor Cin1 Amplifier IA in one end and first order gain amplifying circuit 1031Output end, capacitor C1One end, resistance Rp3One end connection, capacitor Cin1The other end and resistance Rp5The input terminal connection of one end, second level copped wave operational amplification circuit 202, resistance Rp5The other end and electricity Press VCMConnection, capacitor Cin2Amplifier IA in one end and first order gain amplifying circuit 1032Output end, capacitor C2One end, electricity Hinder Rp4One end connection, capacitor Cin2The other end and resistance Rp6One end, second level copped wave operational amplification circuit 202 input terminal connect It connects, resistance Rp6The other end and voltage VCMConnection.In the present embodiment, by blocking biasing circuit 201 carry out blocking handle to obtain every The first ECG signal after straight provides direct current biasing for first order gain amplifying circuit 103.In the present embodiment, voltage VCMValue It is 0.5*VDD.
Second level copped wave operational amplification circuit 202, including difference amplifier GM1, chopping modulation device CH3, difference amplifier GM2, capacitor Cm1With capacitor Cm2, wherein difference amplifier GM1C in normal phase input end and blocking biasing circuit 201in1One end and Resistance Rp5The output end connection of one end, the output end of the first feedback loop 203, second feed back loop 204, difference amplifier GM1 Inverting input terminal and capacitor Cin2One end, resistance Rp6One end, the output end of the first feedback loop 203, second feed back loop 204 Output end connection, difference amplifier GM1Positive output end and chopping modulation device CH3First input end, Ripple Suppression circuit 205 Output end connection, difference amplifier GM1Reversed-phase output and chopping modulation device CH3The second input terminal, Ripple Suppression circuit 205 output end connection, chopping modulation device CH3The first output end and difference amplifier GM2Inverting input terminal, capacitor Cm1One end Connection, chopping modulation device CH3Second output terminal and difference amplifier GM2Normal phase input end, capacitor Cm2One end connection, difference are put Big device GM2Positive output end and capacitor Cm1The other end, the first feedback loop 203 input terminal, second feed back loop 204 input End, the connection of the input terminal in Ripple Suppression circuit 205, signal output end, difference amplifier GM2Reversed-phase output and capacitor Cm2It is another End, the input terminal of the first feedback loop 203, the input terminal of second feed back loop 204, Ripple Suppression circuit 205 input terminal connect It connects.In the present embodiment, second level copped wave operational amplification circuit 202 passes through difference amplifier GM to the first ECG signal after blocking1 After enhanced processing, then pass through chopping modulation device CH3Chopping modulation processing is carried out, by the first ECG signal after blocking from high frequency Chopping modulation returns low frequency, then the signal for modulating back low frequency is passed through difference amplifier GM2Again after enhanced processing, output second is adjusted ECG signal processed.Meanwhile in the present embodiment, second level copped wave operational amplification circuit 202 is that second level magnifier 2 provides DC current gain provides driving capability.
First feedback loop 203 includes capacitor Cfb3, capacitor Cfb4, chopping modulation device GH2, integrator Int1, integrator Int1 First input end and second level copped wave operational amplification circuit 202 in difference amplifier GM2Positive output end and capacitor Cm1One End connection, integrator Int1The second input terminal and second level copped wave operational amplification circuit 202 in difference amplifier GM2It is anti- Output end and capacitor Cm2One end connection, integrator Int1The first output end and chopping modulation device GH2First input end connection, Integrator Int1Second output terminal and chopping modulation device GH2The second input terminal connection, chopping modulation device GH2First output End and capacitor Cfb3One end connection, chopping modulation device GH2Second output terminal and capacitor Cfb4One end connection, capacitor Cfb3The other end With the C in blocking biasing circuit 201in2One end and resistance Rp6Difference in one end, second level copped wave operational amplification circuit 202 is put Big device GM1Inverting input terminal connection, capacitor Cfb4C in the other end and blocking biasing circuit 201in1One end and resistance Rp5One end, Difference amplifier GM in second level copped wave operational amplification circuit 2021Normal phase input end connection.In the present embodiment, because of electrode Offset voltage is a very low frequencies signal, can achieve 50mV for wet electrode maximum, and dry electrode maximum can achieve 300mV, This easily causes the saturation of circuit, therefore the present embodiment introduces the first feedback loop 203, specifically DC feedback loop, i.e. DSL The circuit (DC-Servo Loop, abbreviation DSL).First feedback loop 203 is first from second level copped wave operational amplification circuit 202 Output end obtains the second modulation ECG signal, then passes through a large time constant integrator Int1Obtain the second modulation ECG signal In DC component signal, then the DC component signal of the second modulation ECG signal that will acquire is by chopping modulation device CH2Modulation To high frequency, the DC component signal for being modulated to high frequency is finally fed back to the input terminal of second level copped wave operational amplification circuit 202, To be offseted with from the electrode DC offset voltage in the first ECG signal of blocking that blocking biasing circuit 201 exports, it is suppressed that Electrode DC offset voltage.
Second feed back loop 204 includes capacitor Cfb1, capacitor Cfb2, chopping modulation device GH5, chopping modulation device GH5It is first defeated Enter the difference amplifier GM in end and second level copped wave operational amplification circuit 2022Reversed-phase output and capacitor Cm2One end connection, cuts Wave modulator GH5The second input terminal and second level copped wave operational amplification circuit 202 in difference amplifier GM2Positive output end With capacitor Cm1One end connection, chopping modulation device GH5The first output end and capacitor Cfb1One end connection, capacitor Cfb1The other end with every C in straight biasing circuit 201in1One end and resistance Rp5Difference amplifier in one end, second level copped wave operational amplification circuit 202 GM1Normal phase input end connection, chopping modulation device GH5Second output terminal and capacitor Cfb2One end connection, capacitor Cfb2The other end with every C in straight biasing circuit 201in2One end and resistance Rp6Difference amplifier in one end, second level copped wave operational amplification circuit 202 GM1Inverting input terminal connection.In the present embodiment, output of the second feed back loop 204 from second level copped wave operational amplification circuit 202 End obtains the second modulation ECG signal of output, and the second modulation ECG signal is passed through chopping modulation device GH5It is modulated to high frequency, then will The the second modulation ECG signal for being modulated to high frequency feeds back to the input terminal of second level copped wave operational amplification circuit 202；Meanwhile blocking Input capacitance C in biasing circuit 201in1, capacitor Cin2With the feedback capacity C in second feed back loop 204fb1, capacitor Cfb2's The gain coefficient of ratio composition second level magnifier 20.
Ripple Suppression circuit 205 includes difference amplifier GM3, integrator Int2, chopping modulation device CH4, capacitor Cint1, electricity Hold Cint2, capacitor CS1, capacitor CS2, capacitor CS1Difference amplifier GM in one end and second level copped wave operational amplification circuit 2022Just Phase output terminal and capacitor Cm1One end connection, capacitor CS1The other end and chopping modulation device CH4First input end connection, capacitor CS2 Difference amplifier GM in one end and second level copped wave operational amplification circuit 2022Reversed-phase output and capacitor Cm2One end connection, electricity Hold CS2The other end and chopping modulation device CH4The second input terminal connection, chopping modulation device CH4The first output end and capacitor Cint1 One end, integrator Int2First input end connection, chopping modulation device CH4Second output terminal and capacitor Cint2One end, integrator Int2The second input terminal connection, integrator Int2The first output end and capacitor Cint2The other end, capacitor Cint1The other end, difference Divide amplifier GM3Input terminal connection, difference amplifier GM3Positive output end and cutting in second level copped wave operational amplification circuit 202 Wave modulator CH3The second input terminal and difference amplifier GM1Reversed-phase output connection, difference amplifier GM3Reversed-phase output with Chopping modulation device CH in second level copped wave operational amplification circuit 2023First input end and difference amplifier GM1Positive output End connection.In the present embodiment, because circuit itself offset voltage and low frequency 1/f noise, under the influence of chopping modulation, meeting exists The output end of second level copped wave operational amplification circuit 202 generates the high frequency ripple of amplitude, therefore ripple is introduced in the present embodiment Inhibit circuit 205, i.e. the circuit RRL (Ripple Reduction Loop, abbreviation RRL), Ripple Suppression circuit 205 is from the second level The output end of copped wave operational amplification circuit 202 obtains the second modulation ECG signal of output, passes through chopping modulation device CH4Carry out pair Second modulation ECG signal chopping modulation processing modulates ripple current signal in ECG signal from high frequency modulated to low for second Frequently, by other electric current low frequency signals in addition to ripple current signal from low frequency modulations to high frequency, then pass through integrator Int2It obtains The ripple current signal for being modulated onto low frequency is taken, the ripple current signal for being modulated to low frequency is finally passed through into difference amplifier GM3 It feeds back to the difference amplifier GM in second level copped wave operational amplification circuit 2021Output end, thus with second level copped wave operation The difference amplifier GM of amplifying circuit 2021Output end output ripple current signal offset, it is suppressed that due to chopping modulation High frequency ripple caused by process.
Wherein, the integrator Int in Ripple Suppression circuit 2052For Ping-Pong integrator, Ping-Pong integrator packet Include Ping structural circuit 2051 and Pong structural circuit 2052.
Specifically, switch S in Ping structural circuit 20511, switch S2, switch S3, switch S4, switch S5, switch S6, switch S7, switch S8, capacitor Cset1, capacitor Cset2, difference amplifier GM4, connection relationship is above-mentioned have been described, and details are not described herein.Its In, switch S1, switch S2, switch S7, switch S8It isSwitch, switch S3, switch S4, switch S5, switch S6It isSwitch,Switch,Switch phase is opposite.
It include switch S in Pong structural circuit 20529, switch S10, switch S11, switch S12, switch S13, switch S14, switch S15, switch S16, capacitor Cset3, capacitor Cset4, difference amplifier GM5, connection relationship is above-mentioned have been described, and details are not described herein. Wherein, switch S9, switch S10, switch S15, switch S16It isSwitch, switch S11, switch S12, switch S13, switch S14 It isSwitch,Switch,Switch phase is opposite.
Further, in Pong structural circuit 2025In switch and Ping structural circuit 2051It opens It is identical to close phase, in Pong structural circuit 2025In switch and Ping structural circuit 2051Switch phase It is identical.
In the present embodiment, Ping-Pong integrator is devised in ripple suppression circuit 205, is used from zeroing technology, Ping-Pong integrator input is connected to by chopping modulation device CH4Output signal, Ping-Pong integrator is by copped wave Modulator CH4The ripple signal for being modulated to low frequency retains, other ECG electric signals for being modulated onto high frequency filter out, thus in Ping- Pong integrator output terminal forms the integral voltage of a ripple signal, while can eliminate from the Ping-Pong structure of zeroing The offset voltage of integrator itself, and pass through difference amplifier GM3The integral voltage is fed back into second level copped wave operation amplifier The difference amplifier GM of circuit 2021Output end, effectively inhibit ECG signal monitoring front-end chip circuits in chopping modulation Bring high frequency ripple, and prevent the generation of secondary ripple wave.
Further, second level copped wave operational amplification circuit 202 be also used to handle the second modulation ECG signal, direct current signal, Ripple signal obtains the second ECG signal.
Specifically, direct current signal, the line of 202 the first feedback loop of real-time reception 203 of second level copped wave operational amplification circuit Wave inhibits the second modulation ECG signal of the ripple signal in circuit 205, second feed back loop 204, to second level copped wave operation amplifier Direct current signal, ripple signal in second modulation ECG signal of circuit 202 are handled, output pseudo-differential copped wave instrument amplification The second final ECG signal of device 1.The present embodiment, by being carried out to direct current signal, the ripple signal in the second modulation ECG signal Processing, available low noise, the second stable ECG signal.
Fig. 7 is referred to, Fig. 7 is the structural schematic diagram that a kind of ECG signal provided in an embodiment of the present invention monitors front-end chip. The present embodiment provides a kind of ECG signal monitoring front-end chip, and the front-end chip is in addition to including that above-mentioned pseudo-differential copped wave instrument is put It further include switch capacitor filter 2, Delta-Sigma modulator 3, wherein switch capacitor filter 2, connection is put outside big device 1 Big device, the second ECG signal for exporting amplifier carry out filtering out noise processed, obtain third ECG signal；Delta- Sigma modulator 3, connection switch capacitive filter 2 obtain the 4th for carrying out analog-to-digital conversion process to third ECG signal ECG signal, the 4th ECG signal are digital signal.
Fig. 8, Fig. 9 are referred to, Fig. 8 is that a kind of ECG signal provided in an embodiment of the present invention monitors switch electricity in front-end chip The circuit diagram of capacitor filter device, Fig. 9 are that a kind of ECG signal provided in an embodiment of the present invention monitors Delta- in front-end chip The circuit diagram of Sigma modulator.Wherein, switch capacitor filter 2 includes level-one switch capacitor filter and secondary switch Capacitive filter, level-one switch capacitor filter and secondary switch capacitive filter cascade.Delta-Sigma modulator 3 includes Three rank feed forward cascaded circuits, comparison circuit and feedback DAC circuit.Specific 2 circuit connection situation of switch capacitor filter please join See Fig. 7, specific 3 circuit connection situation of Delta-Sigma modulator refers to Fig. 8, because switch capacitor filter 2, Delta-Sigma modulator 3 is not innovative point of the invention, so its specific connection does not carry out detailed retouch here It states.
The present embodiment is integrated by the on piece that switch capacitor filter 2 realizes large time constant low-pass filter, realizes The low pass node of 250Hz, has filtered out high-frequency noise and burr caused by 1 copped wave of pseudo-differential copped wave instrument amplifier； Delta-Sigma modulator 3 is using cascade integrator feedforward (Cascade-Integrator-Feedforward, abbreviation CIFF) Topological structure, precision can achieve 12.7.
In order to illustrate the effect of pseudo-differential copped wave instrument amplifier 1 in the present embodiment, front end is monitored based on ECG signal as above The design of chip circuit structure, the present embodiment have carried out a large amount of experiment test, referring to Figure 10, Figure 11, Figure 12, Figure 13, figure 14, Figure 10 monitor the equivalent input noise result of spectrum analysis signal of front-end chip for ECG signal provided in an embodiment of the present invention Figure, Figure 11 are the entire gain response results schematic diagram that ECG signal provided in an embodiment of the present invention monitors front-end chip, Tu12Wei The SDM measured power spectral density result schematic diagram of ECG signal monitoring front-end chip provided in an embodiment of the present invention, Figure 13 are this Test SNR and the SNDR result schematic diagram for the ECG signal monitoring front-end chip that inventive embodiments provide, Figure 14 are that the present invention is implemented The experimental result schematic diagram for the ECG signal measurement that example provides.
Specifically, referring again to Figure 10, abscissa indicates frequency in Figure 10, and ordinate indicates that equivalent input noise spectrum is close Degree, it is seen then that the present embodiment realizes the input noise spectrum density of 37nV/rtHz, and in 0.5~100Hz bandwidth, integrator is made an uproar Sound has been reduced to 0.7uVrms, illustrates that there is the ECG signal monitoring front-end chip proposed in the present embodiment good low frequency to make an uproar Acoustic performance especially has extremely low 1/f noise.
Referring again to Figure 11, abscissa indicates frequency in Figure 11, and ordinate indicates closed loop gain, 3 from top to bottom in figure Adjustable gain bandwidth experimental result when that curve respectively represents is 300V/V, 200V/V and 100V/V, it is seen then that the present embodiment is real The adjustable gain bandwidth for having showed the 100-300V/V in 0.5~250Hz illustrates the ECG signal monitoring proposed in the present embodiment Front-end chip realizes the adjustable gain of electrocardio frequency range, while having electrode imbalance rejection ability.
Referring again to Figure 12, abscissa indicates that frequency, ordinate indicate power spectral density in Figure 12, it is seen then that as input ECG Signal is 180Hz, when 950mVpp, has carried out the test of SDM power spectral density using SDM in the present embodiment, SDM realizes noise Shaping.
Referring again to Figure 13, abscissa indicates normalization input ECG signal size in Figure 13, and ordinate indicates SNR (noise Than) and SNDR (sinad ratio), in conjunction with Figure 12, it is seen then that when SNDR reaches 77.5db, ECG signal that the present embodiment is proposed Monitoring front-end chip realizes 12.7 quantified precisions.
The ECG signal monitoring front-end chip proposed in order to illustrate the present embodiment has normal ECG signal monitoring function, The present embodiment has carried out many experiments measurement, and referring again to Figure 14, abscissa indicates the time in Figure 14, and ordinate indicates voltage, As it can be seen that the present embodiment preferable ECG signal of available quality in practice.
In conclusion the present embodiment is subtracted by the way that the integrated circuit gain of pseudo-differential copped wave instrument amplifier 1 is divided into two-stage Small input capacitance area, and then the area of ECG signal monitoring front-end chip is reduced, the power consumption of chip is reduced, more just It can dress, portable ECG monitoring systematic difference；The present embodiment pseudo-differential copped wave instrument amplifier 1 uses chopping modulation Technology has reduced the interference of 1/f noise and DC offset voltage to ECG signal in ECG signal monitoring front-end chip circuits； The ECG signal of body to be measured is amplified to certain amplitude by the present embodiment pseudo-differential copped wave instrument amplifier 1 undampedly, is increased The amplification factor of ECG signal monitoring front-end chip.
The above content is a further detailed description of the present invention in conjunction with specific preferred embodiments, and it cannot be said that Specific implementation of the invention is only limited to these instructions.For those of ordinary skill in the art to which the present invention belongs, exist Under the premise of not departing from present inventive concept, a number of simple deductions or replacements can also be made, all shall be regarded as belonging to of the invention Protection scope.

Claims (10)

1. a kind of pseudo-differential copped wave instrument amplifier, which is characterized in that the pseudo-differential copped wave instrument amplifier (1) includes: Level-one copped wave artifact parallel circuit (10), second level magnifier (20), wherein
The first order copped wave artifact parallel circuit (10), for defeated to the input terminal of the first order copped wave artifact parallel circuit (10) The ECG signal entered carries out first time chopping modulation and enhanced processing, obtains the first ECG signal；
The second level magnifier (20) connects the first order copped wave artifact parallel circuit (10), for described the One ECG signal carries out second of chopping modulation and enhanced processing, obtains the second ECG signal and amplifies electricity from the second level instrument The output end on road (20) exports second ECG signal.
2. amplifier according to claim 1, which is characterized in that the first order copped wave artifact parallel circuit (10) includes adjusting Unit (101) processed, negative capacitance circuit (102), first order gain amplifying circuit (103), wherein
The modulation unit (101) obtains the first modulation ECG signal for carrying out chopping modulation processing to the ECG signal；
The negative capacitance circuit (102), connects the modulation unit (101), for reducing declining for the first modulation ECG signal Subtract；
The first order gain amplifying circuit (103) connects the modulation unit (101), the negative capacitance circuit (102), uses In amplifying processing to the first modulation ECG signal, first ECG signal is obtained.
3. amplifier according to claim 2, which is characterized in that the negative capacitance circuit (102) includes transistor M1, it is brilliant Body pipe M2, transistor M3, transistor M4, transistor M5, capacitance group Cc1, capacitance group Cc2, wherein
The transistor M1Grid and the first order gain amplifying circuit 103, the capacitance group Cc2One end connection, the crystalline substance Body pipe M1Drain electrode and the capacitance group Cc1One end, the transistor M3Drain electrode connection, the transistor M1Source electrode with it is described Transistor M5Drain electrode, the transistor M2Source electrode connection, the transistor M2Grid and first stage gain amplification electricity Road 103, the capacitance group Cc1The other end, the transistor M2Drain electrode and the capacitance group Cc2The other end, the transistor M4 Drain electrode connection, the transistor M3Grid and the transistor M4Grid connection, the transistor M3Source electrode, described Transistor M4Source electrode in power vd D connection, the transistor M5Grid connect with bias voltage VB, the transistor M5 Source electrode ground connection.
4. amplifier according to claim 3, which is characterized in that the capacitance group Cc1, the capacitance group Cc2Structure is identical, The capacitance group Cc1, the capacitance group Cc2It include several switching capacity groups, wherein
The capacitance group Cc1In several switching capacity groups it is in parallel, and the switching capacity group is serially connected with transistor M1's Drain electrode and described and transistor M2Grid；
The capacitance group Cc2In several switching capacity groups it is in parallel, and the switching capacity group is serially connected with transistor M2Leakage Pole and transistor M1Grid；
Each switching capacity group includes 1 capacitor and 2 switches, and the capacitance series are between the switch.
5. amplifier according to claim 2, which is characterized in that the second level magnifier (20) includes blocking Biasing circuit (201), second level copped wave operational amplification circuit (202), the first feedback loop (203), second feed back loop (204), Ripple Suppression circuit (205), wherein
The blocking biasing circuit (201) connects the first order gain amplifying circuit (103), for believing the first ECG Number carry out blocking processing；
Second level copped wave operational amplification circuit (202) connects the blocking biasing circuit (201), the signal output end, is used for The first ECG signal after the blocking is amplified and chopping modulation is handled, obtains the second modulation ECG signal；
First feedback loop (203) connects the second level copped wave operational amplification circuit (202), is used for described second The direct current signal in the second modulation ECG signal that grade copped wave operational amplification circuit (202) exports feeds back to the second level Copped wave operational amplification circuit (202)；
The Ripple Suppression circuit (205) connects the second level copped wave operational amplification circuit (202), is used for described second The ripple signal in the second modulation ECG signal that grade copped wave operational amplification circuit (202) exports feeds back to second level copped wave Operational amplification circuit (202)；
The second feed back loop (204) connects the second level copped wave operational amplification circuit (202), is used for described second The second modulation ECG signal that grade copped wave operational amplification circuit (202) exports feeds back to second level copped wave operational amplification circuit (202)；
The second level copped wave operational amplification circuit (202) is also used to handle the second modulation ECG signal, direct current letter Number, the ripple signal, obtain second ECG signal.
6. amplifier according to claim 5, which is characterized in that second level copped wave operational amplification circuit (202) includes poor Divide amplifier GM1, chopping modulation device CH3, difference amplifier GM2, capacitor Cm1With capacitor Cm2, wherein
The difference amplifier GM1It is input terminal and the blocking biasing circuit (201), first feedback loop (203), described Second feed back loop (204) connection, the difference amplifier GM1Output end and the chopping modulation device CH3Input terminal, the line Wave inhibits circuit (205) connection, the chopping modulation device CH3Output end and the difference amplifier GM2Input terminal, the capacitor Cm1One end, the capacitor Cm2One end connection, the difference amplifier GM2Output end and the capacitor Cm1The other end, the capacitor Cm2The other end, first feedback loop (203), the second feed back loop (204), the Ripple Suppression circuit (205) are even It connects.
7. amplifier according to claim 6, which is characterized in that the Ripple Suppression circuit (205) includes differential amplification Device GM3, integrator Int2, chopping modulation device CH4, capacitor Cint1, capacitor Cint2, capacitor CS1, capacitor CS2, wherein
The capacitor CS1One end and the difference amplifier GM2Positive output end, the capacitor Cm1One end connection, the capacitor CS1 The other end and the chopping modulation device CH4First input end connection, the capacitor CS2One end and the difference amplifier GM2Instead Phase output terminal, the capacitor Cm2One end connection, the capacitor CS2The other end and the chopping modulation device CH4The second input terminal connect It connects, the chopping modulation device CH4The first output end and the capacitor Cint1One end, the integrator Int2First input end Connection, the chopping modulation device CH4Second output terminal and the capacitor Cint2One end, the integrator Int2Second input End connection, the integrator Int2The first output end and the capacitor Cint2The other end, the capacitor Cint1It is the other end, described Difference amplifier GM3Input terminal connection, the difference amplifier GM3Positive output end and the chopping modulation device CH3It is second defeated Enter end, the difference amplifier GM1Reversed-phase output connection, the difference amplifier GM3Reversed-phase output and the chopping modulation Device CH3First input end, the difference amplifier GM1Positive output end connection.
8. amplifier according to claim 7, which is characterized in that the integrator Int2For Ping-Pong integrator, institute Stating Ping-Pong integrator includes Ping structural circuit (2051) and Pong structural circuit (2052), wherein
The Ping structural circuit (2051) includes switch S1, switch S2, switch S3, switch S4, switch S5, switch S6, switch S7、 Switch S8, capacitor Cset1, capacitor Cset2, difference amplifier GM4, the switch S1One end and the chopping modulation device CH4First Output end, the capacitor Cint1One end connection, the switch S1The other end and the switch S3One end, the capacitor Cset1One end Connection, the capacitor Cset1The other end and the switch S5One end, the difference amplifier GM4Normal phase input end connection, it is described to open Close S5The other end and the difference amplifier GM4Reversed-phase output, the switch S7One end connection, the switch S7The other end with The capacitor Cint1The other end, the difference amplifier GM3Normal phase input end connection, the switch S2One end and the copped wave tune Device CH processed4Second output terminal, the capacitor Cint2One end connection, the switch S2The other end and the switch S4It is one end, described Capacitor Cset2One end connection, the capacitor Cset2The other end and the switch S6One end, the difference amplifier GM4Anti-phase input End connection, the switch S6The other end and the difference amplifier GM4Positive output end, the switch S8One end connection, it is described to open Close S8The other end and the capacitor Cint2The other end, the difference amplifier GM3Inverting input terminal connection, the switch S3It is another End and the switch S4The other end meets VCM；
The Pong structural circuit (2052) includes switch S9, switch S10, switch S11, switch S12, switch S13, switch S14, switch S15, switch S16, capacitor Cset3, capacitor Cset4, difference amplifier GM5, the switch S9One end and the chopping modulation device CH4's First output end, the capacitor Cint1One end connection, the switch S9The other end and the switch S11One end, the capacitor Cset3 One end connection, the capacitor Cset3The other end and the switch S13One end, the difference amplifier GM5Normal phase input end connection, The switch S13The other end and the difference amplifier GM5Reversed-phase output, the switch S15One end connection, the switch S15 The other end and the capacitor Cint1The other end, the difference amplifier GM3Normal phase input end connection, the switch S10One end and institute State chopping modulation device CH4Second output terminal, the capacitor Cint2One end connection, the switch S10The other end and the switch S12 One end, the capacitor Cset4One end connection, the capacitor Cset4The other end and the switch S14One end, the difference amplifier GM5 Inverting input terminal connection, the switch S14The other end and the difference amplifier GM5Positive output end, the switch S16One end connects It connects, the switch S16The other end and the capacitor Cint2The other end, the difference amplifier GM3Inverting input terminal connection, it is described Switch S11The other end and the switch S12The other end meets VCM。
9. a kind of ECG signal monitors front-end chip, which is characterized in that including any one amplifier described in claim 1~8.
10. front-end chip according to claim 9, which is characterized in that the front-end chip further includes switch-capacitor filtering Device (2), Delta-Sigma modulator (3), wherein
The switch capacitor filter (2), connects the amplifier, the 2nd ECG letter for exporting the amplifier It number carries out filtering out noise processed, obtains third ECG signal；
The Delta-Sigma modulator (3), connects the switch capacitor filter (2), for the third ECG signal Analog-to-digital conversion process is carried out, the 4th ECG signal is obtained.
CN201910130707.7A 2019-02-21 2019-02-21 A kind of pseudo-differential copped wave instrument amplifier and its ECG signal monitor front-end chip Pending CN109962682A (en)

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CN110693482B (en) * 2019-08-23 2020-12-22 西安电子科技大学 Analog front-end circuit applied to electrocardiosignal acquisition
CN111682853A (en) * 2020-06-15 2020-09-18 电子科技大学 Alternating capacitor network of capacitor coupling chopper amplifier
CN111682853B (en) * 2020-06-15 2023-05-16 电子科技大学 Alternating capacitor network of capacitive coupling chopper amplifier
CN113783574A (en) * 2021-09-30 2021-12-10 南方电网数字电网研究院有限公司 Modulation circuit
CN113783574B (en) * 2021-09-30 2024-03-26 南方电网数字电网研究院有限公司 Modulation circuit
CN114983424A (en) * 2022-08-03 2022-09-02 之江实验室 Multichannel mixed chopping method and system applied to brain-computer interface chip
CN114983424B (en) * 2022-08-03 2022-11-15 之江实验室 Multichannel mixed chopping method and system applied to brain-computer interface chip
CN116232241A (en) * 2023-05-06 2023-06-06 南方电网数字电网研究院有限公司 Instrument amplifying circuit and current monitor
CN116232241B (en) * 2023-05-06 2023-09-15 南方电网数字电网研究院有限公司 Instrument amplifying circuit and current monitor
CN117254816A (en) * 2023-11-17 2023-12-19 杭州万高科技股份有限公司 Low-noise analog-to-digital conversion interface circuit
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Application publication date: 20190702