CN109194304A - A kind of bandpass filter suitable for physiological single processing - Google Patents
A kind of bandpass filter suitable for physiological single processing Download PDFInfo
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- CN109194304A CN109194304A CN201810767086.9A CN201810767086A CN109194304A CN 109194304 A CN109194304 A CN 109194304A CN 201810767086 A CN201810767086 A CN 201810767086A CN 109194304 A CN109194304 A CN 109194304A
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- pass filter
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- operational transconductance
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- 239000003990 capacitor Substances 0.000 claims abstract description 22
- 238000005516 engineering process Methods 0.000 claims abstract description 9
- 238000001914 filtration Methods 0.000 claims description 4
- 238000010586 diagram Methods 0.000 description 3
- 230000003321 amplification Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000003745 diagnosis Methods 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 238000003199 nucleic acid amplification method Methods 0.000 description 1
Classifications
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H17/00—Networks using digital techniques
- H03H17/02—Frequency selective networks
- H03H17/0202—Two or more dimensional filters; Filters for complex signals
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H17/00—Networks using digital techniques
- H03H2017/0072—Theoretical filter design
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- Engineering & Computer Science (AREA)
- Computer Hardware Design (AREA)
- Mathematical Physics (AREA)
- Networks Using Active Elements (AREA)
Abstract
A kind of bandpass filter suitable for physiological single processing includes high-pass filter, low-pass filter, buffer and output buffer；The high-pass filter cascades the low-pass filter after buffer；The high-pass filter includes operational transconductance amplifier and low-pass filter；The low-pass filter includes operational transconductance amplifier and capacitor, capacity earth；The present invention is converted to a cutoff frequency high-pass filter higher than its by the low-pass filter that OTA-C technology is realized for one by negative feedback structure, and structure is simple, and is not necessarily to biggish resistance or capacitor, saves chip area.And this structure is realized by the similar OTA-C low-pass filter of two structures, using only the capacitor being grounded to one end, the capacitor can be by standard CMOS technology realization, saving one layer is the mask layer for realizing all earth-free capacitor in both ends, it further reduces costs, is more advantageous to system and does commercialization popularization in the market in consumer portable, wearable biomedical device.
Description
Technical field
The present invention relates to integrated circuits, especially provide a kind of bandpass filter suitable for physiological single processing.
Background technique
In recent years, electronic equipment is in biologic medical field using more and more extensive.Integrated circuit is small in size because of having,
Light-weight feature is particularly suitable for intelligentized portable or wearable Medical Devices, one for real-time monitoring human body
A little physiological characteristics provide foundation for medical diagnosis.
The frequency of physiological signal is generally lower, usually between 20Hz ~ 20kHz frequency range.In order to preferably obtain physiological signal,
Some interference and noise signal are filtered off simultaneously, it would be desirable to by bandpass filter.And in order to realize the filtering of low cutoff frequency
Device, it usually needs the resistance and capacitor of very big numerical value；This means that biggish chip area and high cost, are unfavorable for product
Commercialization promote.
Summary of the invention
To solve the above-mentioned problems, that the object of the present invention is to provide a kind of integrated levels is high, circuit area is small, is able to achieve low section
The only bandpass filter suitable for physiological single processing of frequency.
In order to achieve the above objectives, technical scheme is as follows: a kind of bandpass filtering suitable for physiological single processing
Device, including high-pass filter (HPF), low-pass filter (LPF2), buffer (Buffer) and output buffer (Output
Buffer)；The high-pass filter (HPF) cascades the low-pass filter (LPF2) after buffer (Buffer)；It is described
Low-pass filter (LPF2) other end connects output buffer (Output Buffer)；The high-pass filter (HPF) include across
Lead operational amplifier (OTA1) and low-pass filter (LPF1)；The low-pass filter (LPF1) includes operational transconductance amplifier
(OTA2) and capacitor (C1), the non-inverting input terminal of the operational transconductance amplifier (OTA2) connect the operational transconductance amplifier
(OTA1) output end, inverting input terminal connects the inverting input terminal of output end and the operational transconductance amplifier (OTA1), defeated
Outlet is grounded by capacitor (C1)；The low-pass filter (LPF2) includes operational transconductance amplifier (OTA3) and capacitor (C2),
The non-inverting input terminal of the operational transconductance amplifier (OTA3) connects the buffer (Buffer), inverting input terminal connection output
End, output end connect output buffer (Output Buffer), and are grounded by capacitor (C2).
Further, the cutoff frequency of the low-pass filter (LPF1) is extremely low, using resistance decoupling and two kinds of current distributing
Technology, and realized by lesser bias current.
Further, the cutoff frequency of the low-pass filter (LPF2) is in 20kHz or so.
Further, described two low-pass filter (LPF1, LPF2) structures are similar.
The beneficial effects of the present invention are: the low pass filtered that the present invention is realized one by OTA-C technology by negative feedback structure
Wave device is converted to a cutoff frequency high-pass filter higher than its, and structure is simple, and is not necessarily to biggish resistance or capacitor, section
Chip area is saved.And this structure is realized by the similar OTA-C low-pass filter of two structures, is grounded using only to one end
Capacitor, the capacitor can by standard CMOS technology realization, save one layer be realize all earth-free capacitor in both ends exposure mask
Layer, further reduces costs, is more advantageous to system in consumer portable, wearable biomedical device market
On do commercialization promote.
Detailed description of the invention
Fig. 1 is the structural schematic diagram based on OTA-C bandpass filter of the invention；Fig. 2 is low based on OTA-C of the invention
The amplitude frequency curve schematic diagram of bandpass filter；Fig. 3 is the amplitude frequency curve schematic diagram based on OTA-C high-pass filter of the invention.
Specific embodiment
It describes the specific embodiments of the present invention in detail with reference to the accompanying drawing.
As shown in Figure 1, a kind of bandpass filter suitable for physiological single processing, including high-pass filter (HPF), low pass
Filter (LPF2), buffer (Buffer) and output buffer (Output Buffer)；High-pass filter (HPF) warp
It crosses buffer (Buffer) and cascades the low-pass filter (LPF2) afterwards；Low-pass filter (LPF2) other end connection output
Buffer (Output Buffer)；The high-pass filter (HPF) includes operational transconductance amplifier (OTA1) and low-pass filter
(LPF1)；The low-pass filter (LPF1) includes operational transconductance amplifier (OTA2) and capacitor (C1), and the operational transconductance is put
The non-inverting input terminal of big device (OTA2) connects the output end of the operational transconductance amplifier (OTA1), inverting input terminal connection output
The inverting input terminal at end and the operational transconductance amplifier (OTA1), output end are grounded by capacitor (C1)；The low-pass filtering
Device (LPF2) includes operational transconductance amplifier (OTA3) and capacitor (C2), the homophase input of the operational transconductance amplifier (OTA3)
End connects the buffer (Buffer), and inverting input terminal connects output end, and output end connects output buffer (Output
Buffer it), and by capacitor (C2) is grounded.
The cutoff frequency of the low-pass filter (LPF1) is extremely low, using two kinds of technologies of resistance decoupling and current distributing, and
It is realized by lesser bias current.
The cutoff frequency of the low-pass filter (LPF2) is in 20kHz or so.
Described two low-pass filter (LPF1, LPF2) structures are similar.
Now following formula is carried out to its principle to illustrate:
Formula 1)
Wherein, v2 is the output of high-pass filter；A1 is the gain of operational transconductance amplifier OTA1；τ=C1/Gm2, Gm2 be across
Lead the mutual conductance of operational amplifier OTA2.From formula 1) we can release:
Formula 2)
The transfer function of the high-pass filter thus of formula 2, the zero pole point of this function are respectively as follows:
Zero point:,
Pole:
The above analytic explanation uses structure of the invention can be by a cutoff frequency for low-pass filter (its amplitude-frequency spy of 1/ τ
Property illustrated by Fig. 2), be converted into a cutoff frequency be (A1+1)/τ high-pass filter (its amplitude-frequency characteristic is illustrated by Fig. 3).Though
The cutoff frequency of right the latter is A1 times big than the former, but if OTA low-pass filter use resistance decouple with dividing technology with
And lesser bias current can obtain a very low cutoff frequency (~ 0.1Hz), accordingly even when A1 times of amplification, we also can
Obtain the cutoff frequency of the lower high-pass filter of 20Hz or so.
Low-pass filter (LPF2) can also realize 20kHz cutoff frequency by above-mentioned technology, realize difficulty than low
Bandpass filter (LPF1) it is lower.
It is to be illustrated to preferable implementation of the invention, but the invention is not limited to the implementation above
Example, those skilled in the art can also make various equivalent variations on the premise of without prejudice to spirit of the invention or replace
It changes, these equivalent deformations or replacement are all included in the scope defined by the claims of the present application.
Claims (4)
1. a kind of bandpass filter suitable for physiological single processing, it is characterised in that: including high-pass filter (HPF), low pass
Filter (LPF2), buffer (Buffer) and output buffer (Output Buffer)；High-pass filter (HPF) warp
It crosses buffer (Buffer) and cascades the low-pass filter (LPF2) afterwards；Low-pass filter (LPF2) other end connection output
Buffer (Output Buffer)；The high-pass filter (HPF) includes operational transconductance amplifier (OTA1) and low-pass filter
(LPF1)；The low-pass filter (LPF1) includes operational transconductance amplifier (OTA2) and capacitor (C1), and the operational transconductance is put
The non-inverting input terminal of big device (OTA2) connects the output end of the operational transconductance amplifier (OTA1), inverting input terminal connection output
The inverting input terminal at end and the operational transconductance amplifier (OTA1), output end are grounded by capacitor (C1)；The low-pass filtering
Device (LPF2) includes operational transconductance amplifier (OTA3) and capacitor (C2), the homophase input of the operational transconductance amplifier (OTA3)
End connects the buffer (Buffer), and inverting input terminal connects output end, and output end connects output buffer (Output
Buffer it), and by capacitor (C2) is grounded.
2. a kind of bandpass filter suitable for physiological single processing according to claim 1, it is characterised in that: described low
The cutoff frequency of bandpass filter (LPF1) is extremely low, using two kinds of technologies of resistance decoupling and current distributing, and passes through lesser biasing
Electric current is realized.
3. a kind of bandpass filter suitable for physiological single processing according to claim 1, it is characterised in that: described low
The cutoff frequency of bandpass filter (LPF2) is in 20kHz or so.
4. a kind of bandpass filter suitable for physiological single processing according to claim 1, it is characterised in that: described two
A low-pass filter (LPF1, LPF2) structure is similar.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810767086.9A CN109194304B (en) | 2018-07-13 | 2018-07-13 | Band-pass filter suitable for physiological signal processing |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810767086.9A CN109194304B (en) | 2018-07-13 | 2018-07-13 | Band-pass filter suitable for physiological signal processing |
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| CN109194304A true CN109194304A (en) | 2019-01-11 |
| CN109194304B CN109194304B (en) | 2023-02-14 |
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1062439A (en) * | 1990-11-29 | 1992-07-01 | 德国汤姆森-勃朗特有限公司 | Universal filter |
| US20060267760A1 (en) * | 2005-05-20 | 2006-11-30 | Gard Dog, Llc | Child safety alarm |
| US20070146062A1 (en) * | 2005-12-28 | 2007-06-28 | Sanyo Electric Co., Ltd. | Active filer circuit for limiting band of input signal |
| US20100031205A1 (en) * | 2008-08-04 | 2010-02-04 | Chung Yuan Christian University | Analytical synthesis method and ota-based circuit structure |
| US20140312964A1 (en) * | 2012-07-16 | 2014-10-23 | King Fahd University Of Petroleum And Minerals | Reconfigurable high-order integrated circuit filters |
| CN104579235A (en) * | 2015-01-21 | 2015-04-29 | 复旦大学 | A Low Power Transconductance Capacitance (Gm-C) Biquadratic Filter |
-
2018
- 2018-07-13 CN CN201810767086.9A patent/CN109194304B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1062439A (en) * | 1990-11-29 | 1992-07-01 | 德国汤姆森-勃朗特有限公司 | Universal filter |
| US20060267760A1 (en) * | 2005-05-20 | 2006-11-30 | Gard Dog, Llc | Child safety alarm |
| US20070146062A1 (en) * | 2005-12-28 | 2007-06-28 | Sanyo Electric Co., Ltd. | Active filer circuit for limiting band of input signal |
| US20100031205A1 (en) * | 2008-08-04 | 2010-02-04 | Chung Yuan Christian University | Analytical synthesis method and ota-based circuit structure |
| US20140312964A1 (en) * | 2012-07-16 | 2014-10-23 | King Fahd University Of Petroleum And Minerals | Reconfigurable high-order integrated circuit filters |
| CN104579235A (en) * | 2015-01-21 | 2015-04-29 | 复旦大学 | A Low Power Transconductance Capacitance (Gm-C) Biquadratic Filter |
Non-Patent Citations (2)
| Title |
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| HSIAO WESU .ET AL: "PERFORMANCE ANALYSIS AND COMPARISON OF", 《JOURNAL OF CIRCUITS,SYSTEMS,AND COMPUTERS》 * |
| 龙英: "全集成连续时间OTA-C有源滤波器的研究", 《中国优秀硕士学位论文全文数据库信息科技辑》 * |
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| CN109194304B (en) | 2023-02-14 |
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