CN107137074A - A kind of instrument amplifier for bioelectrical signals - Google Patents
A kind of instrument amplifier for bioelectrical signals Download PDFInfo
- Publication number
- CN107137074A CN107137074A CN201710210015.4A CN201710210015A CN107137074A CN 107137074 A CN107137074 A CN 107137074A CN 201710210015 A CN201710210015 A CN 201710210015A CN 107137074 A CN107137074 A CN 107137074A
- Authority
- CN
- China
- Prior art keywords
- nmos tube
- pmos
- grid
- drain electrode
- amplifier
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- 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
- A61B5/30—Input circuits therefor
-
- 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]
- A61B5/319—Circuits for simulating ECG signals
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/72—Signal processing specially adapted for physiological signals or for diagnostic purposes
- A61B5/7203—Signal processing specially adapted for physiological signals or for diagnostic purposes for noise prevention, reduction or removal
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/72—Signal processing specially adapted for physiological signals or for diagnostic purposes
- A61B5/7225—Details of analog processing, e.g. isolation amplifier, gain or sensitivity adjustment, filtering, baseline or drift compensation
Abstract
The invention discloses a kind of instrument amplifier for bioelectrical signals, it make it that the flicker noise of instrument amplifier is significantly reduced by using high frequency chopping technology, has reached the noise level of very little.Simultaneously, the present invention is by combining uses of the Ping Pong from zero amplifier structure and capacitance, the elimination of Capacitance Coupled chopper amplifier output ripple is achieved that in primary path so that the output of instrument amplifier is not disturbed by ripple signal, obtains bigger signal swing.In addition, the use that the present invention passes through second level gain variable amplifier and variable Miller capacitance, realize the function of instrument amplifier variable gain bandwidth varying, wherein gain can change from 40dB to 60dB, bandwidth can change from 1kHz to 10kHz, and the main amplifier in gain variable amplifier employs two kinds of power voltage supplies, comparing a kind of amplifier of power voltage supply reduces the power consumption of nearly half.
Description
Technical field
The invention belongs to biologic medical electronic technology field, and in particular to a kind of instrument for bioelectrical signals is amplified
Device.
Background technology
At present, electrocardiogram monitoring system, eeg monitoring system and nerve signal record system are domestic and international biological doctors
Treat a study hotspot of electronic applications.The Record analysis of electrocardiosignal, EEG signals and nerve signal, which possesses, widely should
With value, wherein electrocardiosignal is significant to detection heart physiological pathological change, and EEG signals and nerve signal are to visiting
Survey and diagnosis neurogenic disease, such as epilepsy has very high value, their progress is to following nerve prosthesis, healing nerve
Property disease is significant.Electronic system for recording and detecting bio signal described above, high performance instrument amplification
Device is a vital module.
The frequency band of bioelectrical signals distribution is relatively low, and typically in below 10kHz, and the amplitude of signal is faint, typically several micro-
Lie prostrate between several millivolts.Such as, EEG signals are typically distributed across between 0.5Hz to 100Hz, amplitude be generally 1 μ V to 100 μ V it
Between；Electrocardiosignal is typically distributed across between 0.5Hz to 500Hz, and amplitude is between 1 μ V to 500 μ V；Nerve signal is generally divided into dynamic
Make electric potential signal and local electric potential signal, frequency is respectively between 200Hz to 10kHz and 0.1Hz to 200Hz, and amplitude is also general
In hundreds of microvolts to several millivolts of ranks.Simultaneously in brain electricity, electrocardio, the record system of nerve signal, the electricity for detecting signal
Pole can be because cause output impedance up to several thousand ohms by the attachment of peripheral neurons or cell.Due to the spy of bioelectrical signals
Property, it is desirable to the instrument amplifier applied to bio signal will possess low noise, high cmrr, high input impedance and height and put
Big multiple.
Capacitance Coupled copped wave instrument amplifier is a kind of instrument amplifier class applied to bioelectrical signals more commonly used
Type.Capacitance Coupled copped wave instrument amplifier uses capacitive feedback, and matching precision is relatively high, can reach lower noise level, and
And extra quiescent current is not consumed, low-power consumption and high-gain precision can be reached.Simultaneously as the use of chopper, amplifier
Common-mode rejection ratio it is high, rail-to-rail input voltage range can be reached.Due to these features, copped wave Capacitance Coupled instrument amplifier
More applied to the preamplifier state of bio signal.
But, Capacitance Coupled chopper amplifier is due to the use of chopper, and the equivalent input noise voltage of amplifier can quilt
Copped wave is offset current AC signal of the frequency in chopping frequency, in the Miller capacitance upper integral formation output electricity of post-amplifier
Emboss ripple.If the offset voltage of main amplifier is 10mV, the mutual conductance of main amplifier is 14uS, and Miller capacitance is 18pF, copped wave
Frequency is 20kHz, amplitude about 200mV output voltage ripple will be caused in amplifier out.Due to biologic medical signal
Faint property, output voltage ripple is easy to cause the biologic medical signal after amplification greatly interference, and limits instrument and put
The output voltage swing of big device.Simultaneously as the frequency band of bioelectrical signals is not quite similar, and will be according to the analog-digital converter of rear class
Demand regulation multiplication factor, have gain and the requirement of adaptive-bandwidth to instrument amplifier.
Mainly there is two ways to eliminate the output voltage ripple of Capacitance Coupled chopper amplifier in the prior art.The
A kind of mode is that output voltage ripple is eliminated by way of being followed by low pass filter in Capacitance Coupled chopper amplifier, this side
Formula causes the chopping frequency of chopper amplifier to be that the hundreds of times of low pass filter cutoff frequency can just obtain preferable ripple
Eradicating efficacy.Under normal circumstances, the chopping frequency of Capacitance Coupled chopper amplifier is tens kHz, so section of low pass filter
Only frequency will be less than 1kHz, and low pass filter will realize the cut-off frequency less than 1kHz, electric capacity and electricity in Analogous Integrated Electronic Circuits
Resistance, which can be consumed, to be needed than larger chip area；On the other hand, because the cut-off frequency of low pass filter will be less than 1kHz, this meeting
Limit the applicable range of signal of chopper amplifier.
The second way is by the way that Capacitance Coupled chopper amplifier output voltage ripple is converted into ac current signal, cut
Ac current signal is modulated to DC current signal by ripple device, and DC current signal is integrated by integrator and integrated
Voltage, integral voltage is then converted to the imbalance of current compensation chopper amplifier main amplifier, subtract so as to reach by mutual conductance
The effect of small chopper amplifier output voltage ripple.But, due to the presence of integrator offset voltage, the benefit formed by mutual conductance
The imbalance that electric current tends not to accurately compensate for chopper amplifier is repaid, chopper amplifier output voltage ripple can not be formed very well
Inhibition.
The content of the invention
In view of it is above-mentioned, the invention provides a kind of instrument amplifier for bioelectrical signals, by using high frequency chopping
Technology make it that the flicker noise of instrument amplifier is significantly reduced, and has reached the noise level of very little；Meanwhile, the present invention passes through
With reference to Ping-Pong from the use of zero amplifier structure and capacitance, it is achieved that Capacitance Coupled copped wave is put in primary path
The elimination of big device output ripple so that the output of instrument amplifier is not disturbed by ripple signal, obtains bigger signal swing.
A kind of instrument amplifier for bioelectrical signals, including：
High frequency chopper CHin, for the low frequency differences decomposing biological electric signal of input to be modulated into high frequency differential voltage signal；
Blocking module, for carrying out blocking processing to the high frequency differential voltage signal；
Low imbalance amplification module, for being amplified and drawing in amplification process to the high frequency differential voltage signal after blocking
Enter from zeroing technology and high frequency chopping modulation technique, obtain the differential DC voltages signal of low imbalance, and then to the difference of low imbalance
D. c. voltage signal is divided to carry out copped wave to be modulated to low frequency differential voltage signal；
Class-A modules, for further amplifying to the low frequency differential voltage signal；
Regenerative feedback loop, for being fed to the input of blocking module by the output signal of Class-A modules is positive and negative, so as to carry
The input impedance of high instrument amplifier；
Feedback loop, for by the output signal negative-feedback of Class-A modules to it is low imbalance amplification module input,
So as to control low frequency differences decomposing biological electric signal to the multiplication factor between Class-A module output signals；
Gain-variable amplification module, it is by the overall multiplication factor of regulation meter amplifier to the defeated of Class-A modules
Go out signal to carry out after adjustable amplification and final output.
The blocking module includes two input capacitance Cin1~Cin2With two pseudo- resistance R1~R2；Wherein, input capacitance
Cin1One end and high frequency chopper CHinThe first output end and regenerative feedback loop the first output end be connected, input capacitance
Cin1The other end and pseudo- resistance R1One end, the normal phase input end of low imbalance amplification module and feedback loop it is second defeated
Go out end to be connected, input capacitance Cin2One end and high frequency chopper CHinThe second output end and regenerative feedback loop second output
End is connected, input capacitance Cin2The other end and pseudo- resistance R2One end, the inverting input of low imbalance amplification module and negative anti-
The first output end for presenting loop is connected, pseudo- resistance R1And R2The other end connect outside given input common mode voltage signal.
The low imbalance amplification module includes two capacitance C11~C12, two pseudo- resistance R3~R4, high frequency chopper
CHm, Ping is from zero amplifier and Pong from zero amplifier；Wherein, Ping from the normal phase input end of zero amplifier with
Pong is connected from zero amplifier normal phase input end and as the normal phase input end of low imbalance amplification module, and Ping is from returning to zero amplification
The inverting input of device is connected with Pong from zero amplifier inverting input and as the anti-phase input of low imbalance amplification module
End, Ping is from the positive output end of zero amplifier and Pong from zero amplifier positive output end and capacitance C12One
End is connected, and Ping is from the reversed-phase output of zero amplifier and Pong from zero amplifier reversed-phase output and capacitance C11
One end be connected, capacitance C11The other end and pseudo- resistance R3One end and high frequency chopper CHmFirst input end phase
Even, capacitance C12The other end and pseudo- resistance R4One end and high frequency chopper CHmThe second input be connected, pseudo- resistance
R3And R4The other end connect outside given input common mode voltage signal, high frequency chopper CHmFirst input end and Class-
The inverting input of A modules is connected, high frequency chopper CHmThe second input be connected with the normal phase input end of Class-A modules.
The Ping is identical with the structure of Pong from zero amplifier from zero amplifier, and its concrete structure is opened including seven
Close S1~S7, nine PMOS P1~P9, 12 NMOS tube N1~N12And zeroing electric capacity Caz；Wherein, PMOS P1~P5's
Source electrode connects and meets supply voltage VDD altogether, PMOS P1Grid meet outside given bias voltage Vb1, PMOS P1Drain electrode with
PMOS P6Source electrode and PMOS P7Source electrode be connected, PMOS P6Grid and NMOS tube N3Grid, switch S3One
End and switch S2One end be connected, switch S2The other end as Ping from zero amplifier or Pong from zero amplifier
Inverting input, PMOS P7Grid and NMOS tube N4Grid, switch S3The other end and switch S1One end be connected,
Switch S1The other end as Ping from zero amplifier or Pong from the normal phase input end of zero amplifier, PMOS P6Leakage
Pole and NMOS tube N3Drain electrode, NMOS tube N5Drain electrode and NMOS tube N7Source electrode be connected, PMOS P7Drain electrode and NMOS tube
N4Drain electrode, NMOS tube N6Drain electrode and NMOS tube N8Source electrode be connected, PMOS P2Grid and PMOS P3Grid,
PMOS P5Grid, PMOS P5Drain electrode, NMOS tube N10Drain electrode and NMOS tube N11Drain electrode be connected, PMOS P2's
Drain electrode and PMOS P8Source electrode be connected, PMOS P3Drain electrode and PMOS P9Source electrode be connected, PMOS P4Grid with
PMOS P4Drain electrode, NMOS tube N9Drain electrode and NMOS tube N12Drain electrode be connected, PMOS P8Grid and PMOS P9's
Grid connects and meets outside given bias voltage Vb altogether2, PMOS P8Drain electrode with switch S4One end, NMOS tube N7Drain electrode,
NMOS tube N9Grid and switch S7One end be connected, PMOS P9Drain electrode with switch S5One end, NMOS tube N8Drain electrode,
NMOS tube N12Grid and switch S6One end be connected, switch S7The other end as Ping from zero amplifier or Pong from
The positive output end of zero amplifier, switchs S6The other end as Ping from zero amplifier or Pong from zero amplifier
Reversed-phase output, NMOS tube N7Grid and NMOS tube N8Grid connect altogether and meet outside given bias voltage Vb3, switch S4
The other end and zeroing electric capacity CazOne end and NMOS tube N5Grid be connected, switch S5The other end and zeroing electric capacity Caz's
The other end and NMOS tube N6Grid be connected, NMOS tube N5Source electrode and NMOS tube N3Source electrode, NMOS tube N6Source electrode,
NMOS tube N4Source electrode and NMOS tube N1Drain electrode be connected, NMOS tube N1Grid and NMOS tube N1Grid connect altogether and connect outer
The given bias voltage Vb in portion4, NMOS tube N1Source electrode and NMOS tube N2Source electrode be connected and be grounded, NMOS tube N2Drain electrode with
NMOS tube N9Source electrode, NMOS tube N10Source electrode, NMOS tube N11Source electrode and NMOS tube N12Source electrode be connected, NMOS tube N10
Grid and NMOS tube N11Grid connect altogether and meet outside given bias voltage Vref, switch S1And S2Control pole connect outer
The given switching signal Φ in portionA, switch S3~S5Control pole meet outside given switching signal ΦZ, switch S6And S7Control
System extremely meets outside given switching signal ΦO, the switching signal ΦZWith switching signal ΦOPhase complements.
The Ping is from zero amplifier in switching signal ΦZZeroing school is carried out to the offset voltage of itself in clock phase
Standard, in switching signal ΦOExported after being amplified in clock phase to two-way input signal；The Pong exists from zero amplifier
Switching signal ΦZZeroing calibration is carried out to the offset voltage of itself in clock phase, in switching signal ΦOTo two in clock phase
Road input signal is exported after being amplified；Ping is from the switching signal Φ in zero amplifierZWith Pong from zero amplifier
Switching signal ΦOPhase is consistent.
The regenerative feedback loop is identical with the structure of feedback loop, and its concrete structure includes two feedback capacity Cf1~
Cf2With high frequency chopper CHf；Wherein, high frequency chopper CHfFirst input end be used as regenerative feedback loop or feedback loop
First input end, high frequency chopper CHfThe second input be used as regenerative feedback loop or the second input of feedback loop, it is high
Frequency chopper CHfThe first output end and feedback capacity Cf1One end be connected, feedback capacity Cf1The other end be used as positive feedback loop
Road or the first output end of feedback loop, high frequency chopper CHfThe second output end and feedback capacity Cf2One end be connected, instead
Feed holds Cf2The other end be used as regenerative feedback loop or the second output end of feedback loop.
The Class-A modules include four PMOS P10~P13, seven NMOS tube N13~N19And two Miller capacitances
Cm1~Cm2；Wherein, PMOS P10~P13Source electrode connect altogether and meet supply voltage VDD, PMOS P10Grid and PMOS P11
Grid, PMOS P13Grid, PMOS P13Drain electrode, NMOS tube N17Drain electrode and NMOS tube N18Drain electrode be connected,
PMOS P10Drain electrode and Miller capacitance Cm2One end, NMOS tube N13Drain electrode and NMOS tube N16Grid be connected and conduct
The reversed-phase output of Class-A modules, PMOS P11Drain electrode and Miller capacitance Cm1One end, NMOS tube N14Drain electrode and
NMOS tube N19Grid be connected and be used as the positive output end of Class-A modules, PMOS P12Drain electrode and PMOS P12Grid
Pole, NMOS tube N16Drain electrode and NMOS tube N19Drain electrode be connected, Miller capacitance Cm2The other end and NMOS tube N13Grid phase
Connect and be used as the normal phase input end of Class-A modules, Miller capacitance Cm1The other end and NMOS tube N14Grid be connected and conduct
The inverting input of Class-A modules, NMOS tube N13Source electrode and NMOS tube N14Source electrode and NMOS tube N15Source electrode be connected
And be grounded, NMOS tube N15Grid meet outside given bias voltage Vb4, NMOS tube N15Drain electrode and NMOS tube N16Source electrode,
NMOS tube N17Source electrode, NMOS tube N18Source electrode and NMOS tube N19Source electrode be connected, NMOS tube N17Grid and NMOS tube
N18Grid connect altogether and meet outside given bias voltage Vref。
The gain-variable amplification module includes two capacitance C21~C22, two pseudo- resistance R5~R6, two Millers
Electric capacity C31~C32And gain variable amplifier；Wherein, capacitance C21One end and Class-A modules positive output end
It is connected, capacitance C21The other end and pseudo- resistance R5One end, Miller capacitance C31One end and gain variable amplifier
Inverting input is connected, capacitance C22One end be connected with the reversed-phase output of Class-A modules, capacitance C22It is another
One end and pseudo- resistance R6One end, Miller capacitance C32One end and gain variable amplifier normal phase input end be connected, gain
The positive output end of variable amplifier and pseudo- resistance R5The other end and Miller capacitance C31The other end be connected, gain-variable is put
The reversed-phase output of big device and pseudo- resistance R6The other end and Miller capacitance C32The other end be connected.
The gain variable amplifier includes nine PMOS P14~P22And ten NMOS tube N20~N29；Wherein, PMOS
Pipe P14Source electrode connect 1/2nd supply voltage VDD, PMOS P14Grid meet outside given bias voltage Vb5, PMOS
Pipe P14Drain electrode and PMOS P19Source electrode and PMOS P20Source electrode be connected, PMOS P19Grid and PMOS P22's
Grid is connected and is used as the inverting input of gain variable amplifier, PMOS P20Grid and PMOS P23Grid be connected
And it is used as the normal phase input end of gain variable amplifier, PMOS P19Drain electrode and NMOS tube N22Drain electrode and NMOS tube N28
Source electrode be connected, PMOS P20Drain electrode and NMOS tube N23Drain electrode and NMOS tube N29Source electrode be connected, PMOS P15~
P18Source electrode connect altogether and meet supply voltage VDD, PMOS P15Grid and PMOS P16Grid, PMOS P18Grid,
PMOS P18Drain electrode, NMOS tube N25Drain electrode and NMOS tube N26Drain electrode be connected, PMOS P15Drain electrode and PMOS
P21Source electrode be connected, PMOS P16Drain electrode and PMOS P22Source electrode be connected, PMOS P17Drain electrode and PMOS P17's
Grid, NMOS tube N24Drain electrode and NMOS tube N27Drain electrode be connected, NMOS tube N25Grid and NMOS tube N26Grid connect altogether
And meet outside given bias voltage Vref, PMOS P21Grid and PMOS P22Grid connect altogether and connect outside given inclined
Put voltage Vb6, PMOS P21Drain electrode and NMOS tube N28Drain electrode and NMOS tube N24Grid be connected and be used as gain-variable
The positive output end of amplifier, PMOS P22Drain electrode and NMOS tube N29Drain electrode and NMOS tube N27Grid be connected and make
For the reversed-phase output of gain variable amplifier, NMOS tube N28Grid and NMOS tube N29Grid connect altogether and connect outside given
Bias voltage Vb7, NMOS tube N22Source electrode and NMOS tube N23Source electrode and NMOS tube N20Drain electrode be connected, NMOS tube N20
Grid and NMOS tube N21Grid connect altogether and meet outside given bias voltage Vb4, NMOS tube N20Source electrode and NMOS tube N21
Source electrode be connected and be grounded, NMOS tube N21Drain electrode and NMOS tube N24Source electrode, NMOS tube N25Source electrode, NMOS tube N26Source
Pole and NMOS tube N27Source electrode be connected.
The high frequency chopper CHin、CHmAnd CHfStructure it is identical, its concrete structure is by four cmos transmission gate M1~M4
Composition；Wherein, cmos transmission gate M1Input and cmos transmission gate M3Input be connected and be used as the first of high frequency chopper
Input, cmos transmission gate M1Output end and cmos transmission gate M2Output end be connected and first defeated as high frequency chopper
Go out end, cmos transmission gate M2Input and cmos transmission gate M4Input be connected and as high frequency chopper second input
End, cmos transmission gate M3Output end and cmos transmission gate M4Output end be connected and as the second output end of high frequency chopper,
Cmos transmission gate M1The first control end, cmos transmission gate M2The second control end, cmos transmission gate M3The second control end and
Cmos transmission gate M4The first control end the switching signal ψ of outside offer is providedb, cmos transmission gate M1The second control end, CMOS
Transmission gate M2The first control end, cmos transmission gate M3The first control end and cmos transmission gate M4The second control end connect
Switching signal ψ, switching signal ψ that outside is providedbWith switching signal ψ phase complements.
The pseudo- resistance R1~R6Structure it is identical, its concrete structure is by two PMOS S1~S2Composition；Wherein, PMOS
Pipe S1Source electrode be used as one end of pseudo- resistance, PMOS S1Grid and PMOS S2Grid, PMOS S1Drain electrode and
PMOS S2Drain electrode be connected, PMOS S2Source electrode as pseudo- resistance the other end.
The present invention make it that the flicker noise of instrument amplifier is significantly reduced by using high frequency chopping technology, reaches
The noise level (in 0.5Hz~10kHz signal bandwidth bottom make an uproar 53.9nV/ √ Hz, average noise 54.5nV/ √ Hz) of very little.
Meanwhile, the present invention is achieved that by combining Ping-Pong from the use of zero amplifier structure and capacitance in primary path
The elimination of Capacitance Coupled chopper amplifier output ripple so that the output of instrument amplifier is not disturbed by ripple signal, is obtained
Bigger signal swing.In addition, the present invention is realized by the use of second level gain variable amplifier and variable Miller capacitance
The function of instrument amplifier variable gain bandwidth varying, wherein gain can change from 40dB to 60dB, bandwidth can from 1kHz to
10kHz changes, and the main amplifier in gain variable amplifier employs two kinds of power voltage supplies, compares a kind of power voltage supply
Amplifier reduces the power consumption of nearly half.
Brief description of the drawings
Fig. 1 is the structural representation of instrument amplifier of the present invention.
Fig. 2 is the time diagram of instrument amplifier of the present invention.
Fig. 3 is structural representations of the Ping-Pong from zero amplifier.
Fig. 4 is the structural representation of high frequency chopper.
Fig. 5 is the structural representation of Class-A output stages.
Fig. 6 is the main amplifier structural representation of gain adjustable amplifier.
Fig. 7 is the gain bandwidth variable effects schematic diagram of instrument amplifier of the present invention.
Fig. 8 is the noise effects schematic diagram of instrument amplifier of the present invention.
Embodiment
In order to more specifically describe the present invention, below in conjunction with the accompanying drawings and embodiment is to technical scheme
It is described in detail.
As shown in figure 1, the present invention includes for the instrument amplifier of bioelectrical signals：High frequency chopper CHin, input capacitance
Cin1~Cin2, metal-oxide-semiconductor (M1-2、M3-4、M5-6、M7-8、M9-10、M11-12) formed pseudo- resistance, two structure is identical and sequential is complementary
Ping-Pong from zero amplifier structure, capacitance C11-12, high frequency chopper CHm, Class-A output stages, positive feedback loop
Road, feedback loop and gain adjustable amplifier composition.
The instrument amplifier is first by input high frequency chopper CHinThe bioelectrical signals of input are subjected to copped wave, modulation
To 80kHz, and pass through input capacitance Cin1~Cin2Ping-Pong is transferred to from the input of zero amplifier structure.
Ping-Pong is amplified from zero amplifier structure to the bioelectrical signals for being modulated to high frequency.
Sequential in Fig. 2, in clock phase ΦApingWhen effectively, clock phase ΦZpongEffectively, Ping structures simultaneously
The input of amplifier is connected to the bioelectrical signals for being modulated onto high frequency, and by zeroing electric capacity Caz1Two ends are in ΦZpingClock
The offset voltage formation stored in phase compensates electric current to balance the input offset voltage of Ping structure amplifiers, so that in Ping
The low imbalance high frequency bioelectrical signals of output end one amplification of formation of structure amplifier；Now, Pong is from zero amplifier knot
Structure amplifier in short circuit, output end is connected to zeroing electric capacity Caz2Two ends, so that in zeroing electric capacity Caz2It is upper to form a benefit
Voltage is repaid, the offset voltage can be in next ΦApongThe input offset voltage of Pong structure amplifiers is balanced in clock phase.
Sequential in Fig. 2, in clock phase ΦApongWhen effectively, clock phase ΦZpingEffectively, Pong structures simultaneously
The input of amplifier is connected to the bioelectrical signals for being modulated onto high frequency, and by zeroing electric capacity Caz2Two ends are in ΦZpongClock
The offset voltage formation stored in phase compensates electric current to balance the input offset voltage of Pong structure amplifiers, so that in Pong
The low imbalance high frequency bioelectrical signals of output end one amplification of formation of structure amplifier；Now, Ping is from zero amplifier knot
Structure amplifier in short circuit, output end is connected to zeroing electric capacity Caz1Two ends, so that in zeroing electric capacity Caz1It is upper to form a benefit
Voltage is repaid, the offset voltage can be in next ΦApingThe input offset voltage of Pong structure amplifiers is balanced in clock phase.
Fig. 3 is structural representations of the Ping-Pong from zero amplifier, and Ping-Pong employs electric current from zero amplifier
The technology of multiplexing, will be inputted to pipe PMOS P6-7Current multiplexing in another pair input to pipe NMOS tube N3-4In, so that not
The multiplication factor of amplifier is improved on the premise of increase power consumption in addition.
By Ping-Pong from the technology that returns to zero, the offset voltage of amplifier is suppressed, normally put so as to be operated in
Big state so that the bioelectrical signals Ping-Pong for being modulated onto high frequency realizes amplification from the output end of zero amplifier structure,
Only has the DC offset voltage of amplitude very little from the output end of zero amplifier structure in Ping-Pong simultaneously.
Ping-Pong is connected to from the capacitance C after zero amplifier structure11-12Being modulated onto after amplification can be made
The bioelectrical signals of high frequency pass through, while Ping-Pong is thoroughly disappeared from the residual DC offset voltage of zero amplifier structure
Remove.
The bioelectrical signals for being modulated onto high frequency after amplification are connected on capacitance C11-12High frequency chopper CH afterwardsmCut
Ripple is returned in bioelectrical signals original signal bandwidth, simultaneously because the DC offset voltage of amplifier by Ping-Pong from returning to zero skill
The combined use of art and capacitance is thoroughly eliminated, so as to will not produce because DC offset voltage is adjusted by high frequency modulated chopper
Make the square wave AC signal of high frequency, it is to avoid the output voltage ripple that square-wave signal is formed in Miller capacitance upper integral.This reality
Apply mode medium-high frequency chopper CHmAnd CHinCircuit structure it is as shown in Figure 4.
Class-A output stages are connected to by the bioelectrical signals after the amplification modulated back in original signal bandwidth, by Class-A
Output stage has carried out further signal amplification, and is connected to the first order output end of instrument amplifier.
The circuit structure of Class-A output stages is as shown in figure 5, be connected across the defeated of Class-A output stages in present embodiment
Enter the Miller capacitance C of end and output endm1~Cm2The limit separation in main path signal transmission function can be realized, so as to adjust
Output signal bandwidth.Miller capacitance in present embodiment is adjustable, variable from 5pF to 50pF, so that instrument amplifier
The first order output signal bandwidth can be restricted to 1kHz~10kHz.
The first order output end of instrument amplifier passes through negative-feedback chopper CHfb, negative-feedback electric capacity Cfb1~Cfb2Formed
Feedback loop, the bioelectrical signals after amplifying to instrument amplifier first order output end are relative to instrument amplifier input
The multiplication factor of bioelectrical signals realizes control, and its multiplication factor is (Cin/Cfb), negative-feedback electric capacity C in present embodimentfb1
~Cfb2It is set to 100fF, input capacitance Cin10pF is set to, so the multiplication factor produced is 40dB.
The first order output end of instrument amplifier passes through positive feedback chopper CH simultaneouslypf, negative-feedback electric capacity Cpf1~Cpf2Shape
Into regenerative feedback loop, to input capacitance CinInput provide amplifier needed for input current so that realize increase amplification
The purpose of device input impedance, the input impedance that present embodiment realizes about 20 times by the regenerative feedback loop increases effect.
Gain variable amplifier is as the second level of instrument amplifier, and its input terminates at the defeated of the instrument amplifier first order
Go out on end.Gain variable amplifier can be by changing feedback capacity C31-32Size changes gain factor, with feedback capacity
C31-32It is changed into 1pF from 10pF, the amplifier gain of rear class can be changed into 10 times from 1 times, the instrument amplifier in present embodiment
Entire gain can be changed into 60dB from 40dB times.
Main amplifier in the main amplifier structure of gain variable amplifier shown in Fig. 6, gain variable amplifier is used
Two kinds of power voltage supplies, reduce the overall quiescent dissipation of instrument amplifier.
As shown in fig. 7, by adjusting the Miller capacitance value of the first order and the second stage gain in instrument amplifier in the present invention
Feedback capacitance in variable amplifier, it is possible to achieve a variety of output signal bandwidth and gain effect, shown in Fig. 7 four kinds it is defeated
Exit pattern：1. bioelectrical signals gain 40dB, bandwidth 1kHz are exported；2. bioelectrical signals gain 60dB, bandwidth 1kHz are exported；③
Export bioelectrical signals gain 40dB, bandwidth 10kHz；4. bioelectrical signals gain 60dB, bandwidth 10kHz are exported.
As shown in figure 8, the corner frequency of instrument amplifier flicker noise of the present invention is less than 2Hz, 0.5Hz-10kHz signal bands
Make an uproar 53.9nV/ √ Hz at bottom in width, average noise 54.5nV/ √ Hz, and such noise effects cause bioelectrical signals after amplification
Possess very high signal to noise ratio.
The above-mentioned description to embodiment is understood that for ease of those skilled in the art and using the present invention.
Person skilled in the art obviously can easily make various modifications to above-described embodiment, and described herein general
Principle is applied in other embodiment without passing through performing creative labour.Therefore, the invention is not restricted to above-described embodiment, ability
Field technique personnel are according to the announcement of the present invention, and the improvement made for the present invention and modification all should be in protection scope of the present invention
Within.
Claims (10)
1. a kind of instrument amplifier for bioelectrical signals, it is characterised in that including：
High frequency chopper CHin, for the low frequency differences decomposing biological electric signal of input to be modulated into high frequency differential voltage signal；
Blocking module, for carrying out blocking processing to the high frequency differential voltage signal；
Low imbalance amplification module, for being amplified and being introduced certainly in amplification process to the high frequency differential voltage signal after blocking
Zeroing technology and high frequency chopping modulation technique, obtain the differential DC voltages signal of low imbalance, and then straight to the difference of low imbalance
Stream voltage signal carries out copped wave to be modulated to low frequency differential voltage signal；
Class-A modules, for further amplifying to the low frequency differential voltage signal；
Regenerative feedback loop, for being fed to the input of blocking module by the output signal of Class-A modules is positive and negative, so as to improve instrument
The input impedance of table amplifier；
Feedback loop, for by the output signal negative-feedback of Class-A modules to it is low imbalance amplification module input so that
Low frequency differences decomposing biological electric signal is controlled to the multiplication factor between Class-A module output signals；
Gain-variable amplification module, it is believed the output of Class-A modules by the overall multiplication factor of regulation meter amplifier
Number carry out after adjustable amplification and final output.
2. instrument amplifier according to claim 1, it is characterised in that：The blocking module includes two input capacitances
Cin1~Cin2With two pseudo- resistance R1~R2；Wherein, input capacitance Cin1One end and high frequency chopper CHinThe first output end
And the first output end of regenerative feedback loop is connected, input capacitance Cin1The other end and pseudo- resistance R1One end, low imbalance amplification
The normal phase input end of module and the second output end of feedback loop are connected, input capacitance Cin2One end and high frequency chopper
CHinThe second output end and regenerative feedback loop the second output end be connected, input capacitance Cin2The other end and pseudo- resistance R2's
First output end of one end, the inverting input of low imbalance amplification module and feedback loop is connected, pseudo- resistance R1And R2It is another
One end connects outside given input common mode voltage signal.
3. instrument amplifier according to claim 1, it is characterised in that：The low imbalance amplification module includes two blockings
Electric capacity C11~C12, two pseudo- resistance R3~R4, high frequency chopper CHm, Ping is from zero amplifier and Pong from zero amplifier；
Wherein, Ping is connected from the normal phase input end of zero amplifier with Pong from zero amplifier normal phase input end and as low imbalance
The normal phase input end of amplification module, Ping is from the inverting input of zero amplifier and Pong from zero amplifier inverting input
It is connected and as the inverting input of low imbalance amplification module, Ping returns to zero certainly from the positive output end of zero amplifier with Pong
Amplifier positive output end and capacitance C12One end be connected, Ping from the reversed-phase output of zero amplifier and Pong from
Zero amplifier reversed-phase output and capacitance C11One end be connected, capacitance C11The other end and pseudo- resistance R3One
End and high frequency chopper CHmFirst input end be connected, capacitance C12The other end and pseudo- resistance R4One end and height
Frequency chopper CHmThe second input be connected, pseudo- resistance R3And R4The other end connect outside given input common mode voltage letter
Number, high frequency chopper CHmFirst input end be connected with the inverting input of Class-A modules, high frequency chopper CHmSecond
Input is connected with the normal phase input end of Class-A modules.
4. instrument amplifier according to claim 3, it is characterised in that：The Ping is from zero amplifier and Pong self-regulateds
The structure of nucleus amplifier is identical, and its concrete structure includes seven switch S1~S7, nine PMOS P1~P9, 12 NMOS tube N1
~N12And zeroing electric capacity Caz；Wherein, PMOS P1~P5Source electrode connect altogether and meet supply voltage VDD, PMOS P1Grid
Meet outside given bias voltage Vb1, PMOS P1Drain electrode and PMOS P6Source electrode and PMOS P7Source electrode be connected,
PMOS P6Grid and NMOS tube N3Grid, switch S3One end and switch S2One end be connected, switch S2The other end
As Ping from zero amplifier or Pong from the inverting input of zero amplifier, PMOS P7Grid and NMOS tube N4's
Grid, switch S3The other end and switch S1One end be connected, switch S1The other end as Ping from zero amplifier or
Pong is from the normal phase input end of zero amplifier, PMOS P6Drain electrode and NMOS tube N3Drain electrode, NMOS tube N5Drain electrode and
NMOS tube N7Source electrode be connected, PMOS P7Drain electrode and NMOS tube N4Drain electrode, NMOS tube N6Drain electrode and NMOS tube N8's
Source electrode is connected, PMOS P2Grid and PMOS P3Grid, PMOS P5Grid, PMOS P5Drain electrode, NMOS tube N10
Drain electrode and NMOS tube N11Drain electrode be connected, PMOS P2Drain electrode and PMOS P8Source electrode be connected, PMOS P3Drain electrode
With PMOS P9Source electrode be connected, PMOS P4Grid and PMOS P4Drain electrode, NMOS tube N9Drain electrode and NMOS tube N12
Drain electrode be connected, PMOS P8Grid and PMOS P9Grid connect altogether and meet outside given bias voltage Vb2, PMOS
P8Drain electrode with switch S4One end, NMOS tube N7Drain electrode, NMOS tube N9Grid and switch S7One end be connected, PMOS
P9Drain electrode with switch S5One end, NMOS tube N8Drain electrode, NMOS tube N12Grid and switch S6One end be connected, switch
S7The other end as Ping from zero amplifier or Pong from the positive output end of zero amplifier, switch S6The other end make
It is Ping from zero amplifier or Pong from the reversed-phase output of zero amplifier, NMOS tube N7Grid and NMOS tube N8Grid
Extremely connect altogether and meet outside given bias voltage Vb3, switch S4The other end and zeroing electric capacity CazOne end and NMOS tube N5's
Grid is connected, and switchs S5The other end and zeroing electric capacity CazThe other end and NMOS tube N6Grid be connected, NMOS tube N5Source
Pole and NMOS tube N3Source electrode, NMOS tube N6Source electrode, NMOS tube N4Source electrode and NMOS tube N1Drain electrode be connected, NMOS tube N1
Grid and NMOS tube N1Grid connect altogether and meet outside given bias voltage Vb4, NMOS tube N1Source electrode and NMOS tube N2's
Source electrode is connected and is grounded, NMOS tube N2Drain electrode and NMOS tube N9Source electrode, NMOS tube N10Source electrode, NMOS tube N11Source electrode with
And NMOS tube N12Source electrode be connected, NMOS tube N10Grid and NMOS tube N11Grid connect altogether and connect outside given biased electrical
Press Vref, switch S1And S2Control pole meet outside given switching signal ΦA, switch S3~S5Control pole connect outside to
Fixed switching signal ΦZ, switch S6And S7Control pole meet outside given switching signal ΦO, the switching signal ΦZWith opening
OFF signal ΦOPhase complements.
5. instrument amplifier according to claim 4, it is characterised in that：The Ping is from zero amplifier in switching signal
ΦZZeroing calibration is carried out to the offset voltage of itself in clock phase, in switching signal ΦOTwo-way is inputted in clock phase and believed
Exported after number being amplified；The Pong is from zero amplifier in switching signal ΦZTo the offset voltage of itself in clock phase
Zeroing calibration is carried out, in switching signal ΦOExported after being amplified in clock phase to two-way input signal；Ping is put from returning to zero
Switching signal Φ in big deviceZWith Pong from the switching signal Φ in zero amplifierOPhase is consistent.
6. instrument amplifier according to claim 1, it is characterised in that：The knot of the regenerative feedback loop and feedback loop
Structure is identical, and its concrete structure includes two feedback capacity Cf1~Cf2With high frequency chopper CHf；Wherein, high frequency chopper CHf
One input is used as regenerative feedback loop or the first input end of feedback loop, high frequency chopper CHfThe second input conduct
Second input of regenerative feedback loop or feedback loop, high frequency chopper CHfThe first output end and feedback capacity Cf1One
End is connected, feedback capacity Cf1The other end be used as regenerative feedback loop or the first output end of feedback loop, high frequency chopper CHf
The second output end and feedback capacity Cf2One end be connected, feedback capacity Cf2The other end be used as regenerative feedback loop or negative-feedback
Second output end of loop.
7. instrument amplifier according to claim 1, it is characterised in that：The Class-A modules include four PMOSs
P10~P13, seven NMOS tube N13~N19And two Miller capacitance Cm1~Cm2；Wherein, PMOS P10~P13Source electrode connect altogether
And meet supply voltage VDD, PMOS P10Grid and PMOS P11Grid, PMOS P13Grid, PMOS P13Leakage
Pole, NMOS tube N17Drain electrode and NMOS tube N18Drain electrode be connected, PMOS P10Drain electrode and Miller capacitance Cm2One end,
NMOS tube N13Drain electrode and NMOS tube N16Grid be connected and be used as the reversed-phase output of Class-A modules, PMOS P11's
Drain electrode and Miller capacitance Cm1One end, NMOS tube N14Drain electrode and NMOS tube N19Grid be connected and be used as Class-A modules
Positive output end, PMOS P12Drain electrode and PMOS P12Grid, NMOS tube N16Drain electrode and NMOS tube N19Drain electrode
It is connected, Miller capacitance Cm2The other end and NMOS tube N13Grid be connected and as the normal phase input end of Class-A modules, it is close
Strangle electric capacity Cm1The other end and NMOS tube N14Grid be connected and be used as the inverting input of Class-A modules, NMOS tube N13's
Source electrode and NMOS tube N14Source electrode and NMOS tube N15Source electrode be connected and be grounded, NMOS tube N15Grid connect outside given
Bias voltage Vb4, NMOS tube N15Drain electrode and NMOS tube N16Source electrode, NMOS tube N17Source electrode, NMOS tube N18Source electrode and
NMOS tube N19Source electrode be connected, NMOS tube N17Grid and NMOS tube N18Grid connect altogether and connect outside given bias voltage
Vref。
8. instrument amplifier according to claim 1, it is characterised in that：The gain-variable amplification module include two every
Straight electric capacity C21~C22, two pseudo- resistance R5~R6, two Miller capacitance C31~C32And gain variable amplifier；Wherein, blocking
Electric capacity C21One end be connected with the positive output end of Class-A modules, capacitance C21The other end and pseudo- resistance R5One end,
Miller capacitance C31One end and gain variable amplifier inverting input be connected, capacitance C22One end and Class-A
The reversed-phase output of module is connected, capacitance C22The other end and pseudo- resistance R6One end, Miller capacitance C32One end and
The normal phase input end of gain variable amplifier is connected, the positive output end of gain variable amplifier and pseudo- resistance R5The other end with
And Miller capacitance C31The other end be connected, the reversed-phase output of gain variable amplifier and pseudo- resistance R6The other end and Miller
Electric capacity C32The other end be connected；
The gain variable amplifier includes nine PMOS P14~P22And ten NMOS tube N20~N29；Wherein, PMOS P14
Source electrode connect 1/2nd supply voltage VDD, PMOS P14Grid meet outside given bias voltage Vb5, PMOS P14
Drain electrode and PMOS P19Source electrode and PMOS P20Source electrode be connected, PMOS P19Grid and PMOS P22Grid
It is connected and is used as the inverting input of gain variable amplifier, PMOS P20Grid and PMOS P23Grid be connected and make
For the normal phase input end of gain variable amplifier, PMOS P19Drain electrode and NMOS tube N22Drain electrode and NMOS tube N28Source
Extremely it is connected, PMOS P20Drain electrode and NMOS tube N23Drain electrode and NMOS tube N29Source electrode be connected, PMOS P15~P18's
Source electrode connects and meets supply voltage VDD altogether, PMOS P15Grid and PMOS P16Grid, PMOS P18Grid, PMOS
P18Drain electrode, NMOS tube N25Drain electrode and NMOS tube N26Drain electrode be connected, PMOS P15Drain electrode and PMOS P21Source
Extremely it is connected, PMOS P16Drain electrode and PMOS P22Source electrode be connected, PMOS P17Drain electrode and PMOS P17Grid,
NMOS tube N24Drain electrode and NMOS tube N27Drain electrode be connected, NMOS tube N25Grid and NMOS tube N26The common Lian Bingjie of grid
The given bias voltage V in outsideref, PMOS P21Grid and PMOS P22Grid connect altogether and connect outside given biased electrical
Press Vb6, PMOS P21Drain electrode and NMOS tube N28Drain electrode and NMOS tube N24Grid be connected and amplify as gain-variable
The positive output end of device, PMOS P22Drain electrode and NMOS tube N29Drain electrode and NMOS tube N27Grid be connected and be used as increasing
The reversed-phase output of beneficial variable amplifier, NMOS tube N28Grid and NMOS tube N29Grid connect altogether and connect outside given inclined
Put voltage Vb7, NMOS tube N22Source electrode and NMOS tube N23Source electrode and NMOS tube N20Drain electrode be connected, NMOS tube N20Grid
Pole and NMOS tube N21Grid connect altogether and meet outside given bias voltage Vb4, NMOS tube N20Source electrode and NMOS tube N21Source
Extremely it is connected and is grounded, NMOS tube N21Drain electrode and NMOS tube N24Source electrode, NMOS tube N25Source electrode, NMOS tube N26Source electrode with
And NMOS tube N27Source electrode be connected.
9. the instrument amplifier according to claim 1,3 or 6, it is characterised in that：The high frequency chopper CHin、CHmAnd CHf
Structure it is identical, its concrete structure is by four cmos transmission gate M1~M4Composition；Wherein, cmos transmission gate M1Input with
Cmos transmission gate M3Input be connected and be used as the first input end of high frequency chopper, cmos transmission gate M1Output end with
Cmos transmission gate M2Output end be connected and be used as the first output end of high frequency chopper, cmos transmission gate M2Input with
Cmos transmission gate M4Input be connected and be used as the second input of high frequency chopper, cmos transmission gate M3Output end with
Cmos transmission gate M4Output end be connected and be used as the second output end of high frequency chopper, cmos transmission gate M1The first control end,
Cmos transmission gate M2The second control end, cmos transmission gate M3The second control end and cmos transmission gate M4The first control end
The switching signal ψ of outside offer is providedb, cmos transmission gate M1The second control end, cmos transmission gate M2The first control end,
Cmos transmission gate M3The first control end and cmos transmission gate M4The second control end the switching signal ψ of outside offer is provided, open
OFF signal ψbWith switching signal ψ phase complements.
10. the instrument amplifier according to claim 2,3 or 8, it is characterised in that：The pseudo- resistance R1~R6Structure phase
Together, its concrete structure is by two PMOS S1~S2Composition；Wherein, PMOS S1Source electrode be used as one end of pseudo- resistance, PMOS
S1Grid and PMOS S2Grid, PMOS S1Drain electrode and PMOS S2Drain electrode be connected, PMOS S2Source electrode make
For the other end of pseudo- resistance.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710210015.4A CN107137074B (en) | 2017-03-31 | 2017-03-31 | A kind of instrument amplifier for bioelectrical signals |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710210015.4A CN107137074B (en) | 2017-03-31 | 2017-03-31 | A kind of instrument amplifier for bioelectrical signals |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN107137074A true CN107137074A (en) | 2017-09-08 |
| CN107137074B CN107137074B (en) | 2019-09-06 |
Family
ID=59784160
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201710210015.4A Active CN107137074B (en) | 2017-03-31 | 2017-03-31 | A kind of instrument amplifier for bioelectrical signals |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN107137074B (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107994883A (en) * | 2017-12-27 | 2018-05-04 | 山东师范大学 | A kind of chopper amplification conditioning chip system of the faint small-signal of human-body biological |
| CN108309280A (en) * | 2018-02-11 | 2018-07-24 | 许少辉 | The signal intensifier circuit of electrocardiograph |
| CN110638443A (en) * | 2019-11-07 | 2020-01-03 | 福州大学 | Electrocardiosignal reading circuit |
| WO2020177163A1 (en) * | 2019-03-07 | 2020-09-10 | 华南理工大学 | Chopper amplifying circuit employing negative impedance compensation technique |
| CN112532188A (en) * | 2020-12-01 | 2021-03-19 | 浙江大学 | Low-noise high-linearity capacitive coupling amplifier for bioelectric signal measuring circuit |
| CN112543001A (en) * | 2020-12-04 | 2021-03-23 | 江苏科技大学 | Pre-chopper amplifier capable of separating local field potential and action potential |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0235831A (en) * | 1988-07-26 | 1990-02-06 | Nec Corp | Light receiving/amplifying circuit |
| US5663680A (en) * | 1996-04-04 | 1997-09-02 | Nordeng; Arnold E. | Chopper stabilized amplifier having an additional differential amplifier stage for improved noise reduction |
| TW200412712A (en) * | 2003-01-14 | 2004-07-16 | Silicon Integrated Sys Corp | DC offset canceling circuit applied in a variable gain amplifier |
| US7336123B2 (en) * | 2005-03-29 | 2008-02-26 | Semiconductor Technology Academic Research Center | Chopper amplifier circuit apparatus operable at low voltage utilizing switched operational amplifier |
| CN103138760A (en) * | 2012-11-05 | 2013-06-05 | 戴祖渝 | Amplifier with ultralow direct current (DC) offset at input end and analog/digital (A/D) converter |
| CN203071879U (en) * | 2013-01-21 | 2013-07-17 | 成都芯源系统有限公司 | Voltage amplifying system |
| CN103308183A (en) * | 2013-05-31 | 2013-09-18 | 中国科学院微电子研究所 | Reading circuit used for sensor |
| CN104320096A (en) * | 2014-10-04 | 2015-01-28 | 复旦大学 | Microcurrent and current feedback chopper modulation instrument amplifier |
| CN104720786A (en) * | 2013-12-23 | 2015-06-24 | 中国科学院深圳先进技术研究院 | Chip of active electrode for collecting human body surface biological electric signals |
-
2017
- 2017-03-31 CN CN201710210015.4A patent/CN107137074B/en active Active
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0235831A (en) * | 1988-07-26 | 1990-02-06 | Nec Corp | Light receiving/amplifying circuit |
| US5663680A (en) * | 1996-04-04 | 1997-09-02 | Nordeng; Arnold E. | Chopper stabilized amplifier having an additional differential amplifier stage for improved noise reduction |
| TW200412712A (en) * | 2003-01-14 | 2004-07-16 | Silicon Integrated Sys Corp | DC offset canceling circuit applied in a variable gain amplifier |
| US7336123B2 (en) * | 2005-03-29 | 2008-02-26 | Semiconductor Technology Academic Research Center | Chopper amplifier circuit apparatus operable at low voltage utilizing switched operational amplifier |
| CN103138760A (en) * | 2012-11-05 | 2013-06-05 | 戴祖渝 | Amplifier with ultralow direct current (DC) offset at input end and analog/digital (A/D) converter |
| CN203071879U (en) * | 2013-01-21 | 2013-07-17 | 成都芯源系统有限公司 | Voltage amplifying system |
| CN103308183A (en) * | 2013-05-31 | 2013-09-18 | 中国科学院微电子研究所 | Reading circuit used for sensor |
| CN104720786A (en) * | 2013-12-23 | 2015-06-24 | 中国科学院深圳先进技术研究院 | Chip of active electrode for collecting human body surface biological electric signals |
| CN104320096A (en) * | 2014-10-04 | 2015-01-28 | 复旦大学 | Microcurrent and current feedback chopper modulation instrument amplifier |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107994883A (en) * | 2017-12-27 | 2018-05-04 | 山东师范大学 | A kind of chopper amplification conditioning chip system of the faint small-signal of human-body biological |
| CN108309280A (en) * | 2018-02-11 | 2018-07-24 | 许少辉 | The signal intensifier circuit of electrocardiograph |
| WO2020177163A1 (en) * | 2019-03-07 | 2020-09-10 | 华南理工大学 | Chopper amplifying circuit employing negative impedance compensation technique |
| CN110638443A (en) * | 2019-11-07 | 2020-01-03 | 福州大学 | Electrocardiosignal reading circuit |
| CN112532188A (en) * | 2020-12-01 | 2021-03-19 | 浙江大学 | Low-noise high-linearity capacitive coupling amplifier for bioelectric signal measuring circuit |
| CN112543001A (en) * | 2020-12-04 | 2021-03-23 | 江苏科技大学 | Pre-chopper amplifier capable of separating local field potential and action potential |
| CN112543001B (en) * | 2020-12-04 | 2023-09-19 | 江苏科技大学 | Front chopper amplifier capable of separating local field potential and action potential |
Also Published As
| Publication number | Publication date |
|---|---|
| CN107137074B (en) | 2019-09-06 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN107137074B (en) | A kind of instrument amplifier for bioelectrical signals | |
| CN106972834B (en) | A kind of ripple cancellation loop for capacitive coupling chopper amplifier | |
| Ng et al. | A low-power, high CMRR neural amplifier system employing CMOS inverter-based OTAs with CMFB through supply rails | |
| US8937509B2 (en) | Multi-channel biopotential signal acquisition systems | |
| Lee et al. | A chopper stabilized current-feedback instrumentation amplifier for EEG acquisition applications | |
| CN104320096B (en) | Microcurrent and current feedback chopper modulation instrument amplifier | |
| Song et al. | A 430nW 64nV/vHz current-reuse telescopic amplifier for neural recording applications | |
| Koo et al. | A 24.8-μW biopotential amplifier tolerant to 15-V PP Common-mode interference for two-electrode ECG recording in 180-nm CMOS | |
| CN108336974B (en) | Adjustable in-band noise cancellation loop circuit | |
| Nagulapalli et al. | High performance circuit techniques for nueral front-end design in 65nm CMOS | |
| CN110048683A (en) | A kind of chopper current feedback magnifier of low noise | |
| Song et al. | A noise reconfigurable current-reuse resistive feedback amplifier with signal-dependent power consumption for fetal ECG monitoring | |
| Lee et al. | A 250-μW, 18-nV/rtHz current-feedback chopper instrumentation amplifier in 180-nm cmos for high-performance bio-potential sensing applications | |
| Thanapitak et al. | A micropower chopper CBIA with DSL-embedded input stage with 0.4 V EO tolerance for dry-electrode biopotential recording | |
| Luo et al. | Design of a 3.24 μW, 39nV/√ Hz chopper amplifier with 5.5 Hz noise corner frequency for invasive neural signal acquisition | |
| Sepehrian et al. | A low-power current-reuse analog front-end for multi-channel neural signal recording | |
| Rosell et al. | Analysis and assessment of errors in a parallel data acquisition system for electrical impedance tomography | |
| Martincorena-Arraiza et al. | AC coupled amplifier with a resistance multiplier technique for ultra-low frequency operation | |
| Liu et al. | A bio-IA with fast recovery and constant bandwidth for wearable bio-sensors | |
| US9867574B2 (en) | Multi-channel neural signal amplifier system providing high CMRR across an extended frequency range | |
| Della Sala et al. | Sub-μW front-end low noise amplifier for neural recording applications | |
| Vieira et al. | A Sub-1muA Low-PowerLow-NoiseAmplifier with Tunable Gain and Bandwidth for EMG and EOG Biopotential Signals | |
| Sharma et al. | A low-power low-noise amplifier with high CMRR for wearable healthcare applications | |
| Nagulapalli et al. | A VGA Linearity Improvement Technique for ECG Analog Front-End in 65 nm CMOS | |
| Lee et al. | CMRR enhancement technique for IA using three IAs for bio-medical sensor applications |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |