CN104485894A - Common-mode level shift treatment circuit and method for operational amplifier - Google Patents
Common-mode level shift treatment circuit and method for operational amplifier Download PDFInfo
- Publication number
- CN104485894A CN104485894A CN201410640743.5A CN201410640743A CN104485894A CN 104485894 A CN104485894 A CN 104485894A CN 201410640743 A CN201410640743 A CN 201410640743A CN 104485894 A CN104485894 A CN 104485894A
- Authority
- CN
- China
- Prior art keywords
- signal
- operational amplifier
- filter circuit
- carries out
- mode level
- 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.)
- Pending
Links
- 238000000034 method Methods 0.000 title claims abstract description 45
- 238000001914 filtration Methods 0.000 claims abstract description 45
- 230000003321 amplification Effects 0.000 claims description 17
- 238000003199 nucleic acid amplification method Methods 0.000 claims description 17
- 238000003672 processing method Methods 0.000 claims description 7
- 230000003139 buffering effect Effects 0.000 abstract 1
- 230000005540 biological transmission Effects 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- 230000002411 adverse Effects 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 230000005012 migration Effects 0.000 description 2
- 238000013508 migration Methods 0.000 description 2
- 230000002265 prevention Effects 0.000 description 2
- 230000007812 deficiency Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000009916 joint effect Effects 0.000 description 1
- 230000008054 signal transmission Effects 0.000 description 1
- HODRFAVLXIFVTR-RKDXNWHRSA-N tevenel Chemical compound NS(=O)(=O)C1=CC=C([C@@H](O)[C@@H](CO)NC(=O)C(Cl)Cl)C=C1 HODRFAVLXIFVTR-RKDXNWHRSA-N 0.000 description 1
Landscapes
- Amplifiers (AREA)
Abstract
The embodiment of the invention discloses common-mode level shift treatment circuit and method for an operational amplifier. The treatment circuit comprises a buffer for buffering a received signal so as to improve the driving capacity of the signal, a first filter circuit for performing band-pass filtering for the signal processed by the buffer, a first operational amplifier for amplifying the signal processed by the buffer and subjected to band-pass filtering, and a second filter circuit for performing band-pass filtering for the signal amplified by the signal amplifier so as to obtain a filtered signal. By adopting the treatment circuit, the problem of common-mode level shift at the input end and the output end of the operational amplifier during amplifying a signal transmitted through an RF antenna by a wireless manner through the operational amplifier can be solved; the output signals can be kept in the same common-mode level, which facilitates the subsequent treatment on digital signals, and moreover, signal error code can be avoided.
Description
Technical field
The present invention relates to radio-frequency (RF) identification (Radio Frequency Identification, RFID) technical field, especially relate to a kind for the treatment of circuit for operational amplifier common mode level deviation and method thereof.
Background technology
REID is a kind of contactless automatic identification technology, and it is by electromagnetic wave or inductance misfortune conjunction mode transmission of signal, to complete the automatic identification to destination object.Compared with other automatic identification technology such as bar code, magnetic card, Contact Type Ic Card, namely RFID technique have identifying need not manual intervention, can identify that multiple target, information storage are large, can work in the advantages such as various adverse circumstances simultaneously.Therefore, RFID technique has been widely used in the fields such as fixed capital management, production line automation, animal and vehicle identification, highway toll, gate control system, storage, commodity counterfeit prevention, airline baggage management, container management.
With bar code, magnetic card, contact integrated circuit card (Integrated Circuit Card, IC-card) etc. other automatic identification technology compare, namely RFID technique have identifying need not manual intervention, can identify that multiple target, information storage are large, can work in the advantages such as various adverse circumstances simultaneously.Therefore, RFID technique has been widely used in the fields such as fixed capital management, production line automation, animal and vehicle identification, highway toll, gate control system, storage, commodity counterfeit prevention, airline baggage management, container management.Typical radio-frequency recognition system can be divided into label, reader and Back end data treatment system three parts.
Because the information transmission between reader and card is by radio-frequency antenna wireless transmission, signal is more weak, operational amplifier is needed to be amplified, but due to reasons such as domain is asymmetric, process deviations in the process of operational amplifier amplification, make electric current asymmetric, can cause the skew of the input output common mode electrical level of operational amplifier, severe patient can cause signal receiving not out, thus occurs the phenomenons such as card seeking is unsuccessful.
Summary of the invention
The object of the invention is to overcome the deficiencies in the prior art, the invention provides a kind for the treatment of circuit for operational amplifier common mode level deviation and method thereof, can make output signal on same common mode electrical level, convenient Digital Signal Processing below, avoids the mistake occurring signal errors.
In order to solve the problem, the present invention proposes a kind for the treatment of circuit for operational amplifier common mode level deviation, described treatment circuit comprises:
Buffer, for carrying out buffered to the received signal, strengthens the driving force of signal;
First filter circuit, for carrying out bandpass filtering to the signal after described buffer process;
First operational amplifier, carries out signal amplification for carrying out the signal after bandpass filtering to described buffer;
Second filter circuit, carries out bandpass filtering for carrying out the signal after signal amplification to described signal amplifier, obtains filtered signal.
Preferably, described first filter circuit comprises: interconnective first electric capacity, the second electric capacity and the first resistance.
Preferably, described second filter circuit comprises: interconnective 3rd electric capacity, the 4th electric capacity and the second resistance.
Preferably, described treatment circuit also comprises: the second operational amplifier, for amplifying the signal after the second filter circuit process.
Preferably, described first filter circuit is used for the filtering signal after described buffer process being carried out to high-frequency noise.
Preferably, described second filter circuit is used for the filtering signal after described buffer process being carried out to low-frequency noise.
Correspondingly, the present invention also provides a kind of processing method for operational amplifier common mode level deviation, and described method comprises:
Buffer carries out buffered to the received signal; First filter circuit carries out bandpass filtering to the signal after described buffer process; First operational amplifier carries out the signal after bandpass filtering to described buffer and carries out signal amplification; Second filter circuit carries out the signal after signal amplification to described operational amplifier and carries out bandpass filtering, obtains filtered signal.
Preferably, described first filter circuit comprises the step that the signal after described buffer process carries out bandpass filtering: the first filter circuit carries out the filtering of high-frequency noise to the signal after described buffer process.
Preferably, described second filter circuit comprises the step that the signal after described operational amplifier carries out signal amplification carries out bandpass filtering: the second filter circuit carries out the filtering of low-frequency noise to the signal after described buffer process.
Implement the embodiment of the present invention, the signal of radio-frequency antenna wireless transmission can be solved when operational amplifier amplifies, there is the offset problem of the input output common mode electrical level of operational amplifier, can make output signal on same common mode electrical level, convenient Digital Signal Processing below, avoids the mistake occurring signal errors.
Accompanying drawing explanation
In order to be illustrated more clearly in the embodiment of the present invention or technical scheme of the prior art, be briefly described to the accompanying drawing used required in embodiment or description of the prior art below, apparently, accompanying drawing in the following describes is only some embodiments of the present invention, for those of ordinary skill in the art, under the prerequisite not paying creative work, other accompanying drawing can also be obtained according to these accompanying drawings.
Fig. 1 is the structure composition schematic diagram of reader in the embodiment of the present invention;
Fig. 2 is the principle schematic of reader Received signal strength in the embodiment of the present invention;
Fig. 3 is the composition schematic diagram of the treatment circuit for operational amplifier common mode level deviation of the embodiment of the present invention;
Fig. 4 is the schematic flow sheet of the processing method for operational amplifier common mode level deviation of the embodiment of the present invention.
Embodiment
Below in conjunction with the accompanying drawing in the embodiment of the present invention, be clearly and completely described the technical scheme in the embodiment of the present invention, obviously, described embodiment is only the present invention's part embodiment, instead of whole embodiments.Based on the embodiment in the present invention, those of ordinary skill in the art, not making the every other embodiment obtained under creative work prerequisite, belong to the scope of protection of the invention.
Structure with reference to the reader of figure 1 forms, and the simple operation principle of reader Received signal strength is: Received signal strength from antenna, carries out carrier wave filtering to it, just produces the RX reference signal as Fig. 2; Then need by amplifier, this signal to be amplified, as the VRxAmpQ signal of Fig. 2, in the process of amplifying, there will be the problem of common mode electrical level skew, need through overcorrection, then demodulation is carried out to it, give digital processing, otherwise the unsuccessful situation of demodulation may be occurred.
Fig. 3 is the composition schematic diagram of the treatment circuit for operational amplifier common mode level deviation of the embodiment of the present invention, and as shown in Figure 3, this treatment circuit comprises:
Buffer, for carrying out buffered to the received signal, strengthens the driving force of signal;
First filter circuit, for carrying out bandpass filtering to the signal after buffer process;
First operational amplifier, carries out signal amplification for carrying out the signal after bandpass filtering to buffer;
Second filter circuit, carries out bandpass filtering for carrying out the signal after signal amplification to signal amplifier, obtains filtered signal.
In concrete enforcement, the first filter circuit (or filter) carries out bandpass filtering, and this filter circuit serves the effect of adjustment common mode electrical level simultaneously.
Because the signal received is more weak, carrying load ability is not strong, may cause distortion.Thus in treatment circuit of the present invention, add buffer (Amp1), can inhibit signal constant and strengthen its driving force.
First filter circuit carries out bandpass filtering to the signal after buffer process, the low frequency of filtering by
determine, high frequency points is determined by the unity gain bandwidth of amplifier and C2.
In embodiments of the present invention, ensure that 847KHZ must in the logical scope of band, preferably can frequency centered by 847KHZ, so can the decay of filtering to useful signal be dropped to minimum.First filter circuit is used for the filtering signal after buffer process being carried out to high-frequency noise, and high frequency points can suitably be turned down.Here the introducing of buffer can cause the skew of first time common mode electrical level, add the first filter circuit, wherein Vmid is its common mode electrical level voltage, can the enforceable migration by this part be withdrawn on Vmid, thus resolve buffer device this part common mode electrical level skew.
Wherein, the first filter circuit comprises: interconnective first electric capacity, the second electric capacity and the first resistance.
First operational amplifier (Amp1) carries out the signal after bandpass filtering to buffer and carries out signal amplification.
In concrete enforcement, this treatment circuit also comprises: the second operational amplifier (Amp3), for amplifying the signal after the second filter circuit process.
While second time signal amplifies, noise can be amplified together, to while amplifier denoising Processing, band pass filter (the second filter circuit) will have been added later equally here.
In like manner low frequency by
determine, and high frequency points is by closed loop amplifier and C4 joint effect.
Because closed-loop gain is larger, the bandwidth of amplifier is needed wider, so high frequency points can be higher, indifferent to high-frequency suppressing.Second filter circuit is used for the filtering signal after buffer process being carried out to low-frequency noise, here the introducing of buffer can cause the skew of second time common mode electrical level, add the second filter circuit, wherein Vmid is its common mode electrical level voltage, can the mandatory migration by this part be withdrawn on Vmid, thus resolve buffer device this part common mode electrical level skew.
Further, the second filter circuit comprises: interconnective 3rd electric capacity, the 4th electric capacity and the second resistance.
In addition, the embodiment of the present invention additionally provides a kind of processing method for operational amplifier common mode level deviation, and as shown in Figure 4, the method comprises:
S401, buffer carries out buffered to the received signal;
S402, the first filter circuit carries out bandpass filtering to the signal after buffer process;
S403, the first operational amplifier carries out the signal after bandpass filtering to buffer and carries out signal amplification;
S404, the second filter circuit carries out the signal after signal amplification to operational amplifier and carries out bandpass filtering, obtains filtered signal.
Wherein, the first filter circuit comprises the step that the signal after buffer process carries out bandpass filtering: the first filter circuit carries out the filtering of high-frequency noise to the signal after buffer process.
Second filter circuit comprises the step that the signal after operational amplifier carries out signal amplification carries out bandpass filtering: the second filter circuit carries out the filtering of low-frequency noise to the signal after buffer process.
The implementation procedure of the processing method for operational amplifier common mode level deviation of the present invention in the embodiment of the present invention and principle can see embodiment in about the operation principle of each electronic component of the treatment circuit for operational amplifier common mode level deviation and the description of implementation process, repeat no more here.
Implement the embodiment of the present invention, the signal of radio-frequency antenna wireless transmission can be solved when operational amplifier amplifies, there is the offset problem of the input output common mode electrical level of operational amplifier, can make output signal on same common mode electrical level, convenient Digital Signal Processing below, avoids the mistake occurring signal errors.
One of ordinary skill in the art will appreciate that all or part of step in the various methods of above-described embodiment is that the hardware that can carry out instruction relevant by program has come, this program can be stored in a computer-readable recording medium, storage medium can comprise: read-only memory (ROM, Read OnlyMemory), random access memory (RAM, Random Access Memory), disk or CD etc.
In addition, the treatment circuit for operational amplifier common mode level deviation provided the embodiment of the present invention above and method thereof are described in detail, apply specific case herein to set forth principle of the present invention and execution mode, the explanation of above embodiment just understands method of the present invention and core concept thereof for helping; Meanwhile, for one of ordinary skill in the art, according to thought of the present invention, all will change in specific embodiments and applications, in sum, this description should not be construed as limitation of the present invention.
Claims (9)
1. for a treatment circuit for operational amplifier common mode level deviation, it is characterized in that, described treatment circuit comprises:
Buffer, for carrying out buffered to the received signal, strengthens the driving force of signal;
First filter circuit, for carrying out bandpass filtering to the signal after described buffer process;
First operational amplifier, carries out signal amplification for carrying out the signal after bandpass filtering to described buffer;
Second filter circuit, carries out bandpass filtering for carrying out the signal after signal amplification to described signal amplifier, obtains filtered signal.
2., as claimed in claim 1 for the treatment circuit of operational amplifier common mode level deviation, it is characterized in that, described first filter circuit comprises: interconnective first electric capacity, the second electric capacity and the first resistance.
3., as claimed in claim 1 for the treatment circuit of operational amplifier common mode level deviation, it is characterized in that, described second filter circuit comprises: interconnective 3rd electric capacity, the 4th electric capacity and the second resistance.
4., as claimed in claim 1 for the treatment circuit of operational amplifier common mode level deviation, it is characterized in that, described treatment circuit also comprises: the second operational amplifier, for amplifying the signal after the second filter circuit process.
5. as claimed in claim 2 for the treatment circuit of operational amplifier common mode level deviation, it is characterized in that, described first filter circuit is used for the filtering signal after described buffer process being carried out to high-frequency noise.
6. as claimed in claim 3 for the treatment circuit of operational amplifier common mode level deviation, it is characterized in that, described second filter circuit is used for the filtering signal after described buffer process being carried out to low-frequency noise.
7. for a processing method for operational amplifier common mode level deviation, it is characterized in that, described method comprises:
Buffer carries out buffered to the received signal, and the first filter circuit carries out bandpass filtering to the signal after described buffer process; First operational amplifier carries out the signal after bandpass filtering to described buffer and carries out signal amplification; Second filter circuit carries out the signal after signal amplification to described operational amplifier and carries out bandpass filtering, obtains filtered signal.
8. as claimed in claim 7 for the processing method of operational amplifier common mode level deviation, it is characterized in that, described first filter circuit comprises the step that the signal after described buffer process carries out bandpass filtering: the first filter circuit carries out the filtering of high-frequency noise to the signal after described buffer process.
9. as claimed in claim 7 for the processing method of operational amplifier common mode level deviation, it is characterized in that, described second filter circuit comprises the step that the signal after described operational amplifier carries out signal amplification carries out bandpass filtering: the second filter circuit carries out the filtering of low-frequency noise to the signal after described buffer process.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410640743.5A CN104485894A (en) | 2014-11-12 | 2014-11-12 | Common-mode level shift treatment circuit and method for operational amplifier |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410640743.5A CN104485894A (en) | 2014-11-12 | 2014-11-12 | Common-mode level shift treatment circuit and method for operational amplifier |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN104485894A true CN104485894A (en) | 2015-04-01 |
Family
ID=52760411
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201410640743.5A Pending CN104485894A (en) | 2014-11-12 | 2014-11-12 | Common-mode level shift treatment circuit and method for operational amplifier |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN104485894A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110535446A (en) * | 2018-05-24 | 2019-12-03 | 恩智浦有限公司 | The common-mode voltage minimized in the class-D amplifier of AM frequency range transmitting tiltedly becomes |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2000018004A1 (en) * | 1998-09-22 | 2000-03-30 | Qualcomm Incorporated | High efficiency switched gain power amplifier |
| US20070129030A1 (en) * | 2005-12-06 | 2007-06-07 | Texas Instruments Incorporated | High dynamic range pre-power amplifier incorporating digital attenuator |
| CN103279777A (en) * | 2013-05-06 | 2013-09-04 | 西南交通大学 | Wireless surface acoustic wave temperature measurement system reader-writer |
| CN203896313U (en) * | 2014-04-30 | 2014-10-22 | 深圳市华信天线技术有限公司 | Low noise amplifier |
-
2014
- 2014-11-12 CN CN201410640743.5A patent/CN104485894A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2000018004A1 (en) * | 1998-09-22 | 2000-03-30 | Qualcomm Incorporated | High efficiency switched gain power amplifier |
| US20070129030A1 (en) * | 2005-12-06 | 2007-06-07 | Texas Instruments Incorporated | High dynamic range pre-power amplifier incorporating digital attenuator |
| CN103279777A (en) * | 2013-05-06 | 2013-09-04 | 西南交通大学 | Wireless surface acoustic wave temperature measurement system reader-writer |
| CN203896313U (en) * | 2014-04-30 | 2014-10-22 | 深圳市华信天线技术有限公司 | Low noise amplifier |
Non-Patent Citations (1)
| Title |
|---|
| 戴逸飞: "13.56MHz阅读器芯片射频接口的研究和设计", 《中国优秀硕士学位论文全文数据库 信息科技辑》 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110535446A (en) * | 2018-05-24 | 2019-12-03 | 恩智浦有限公司 | The common-mode voltage minimized in the class-D amplifier of AM frequency range transmitting tiltedly becomes |
| CN110535446B (en) * | 2018-05-24 | 2022-10-04 | 恩智浦有限公司 | Minimizing common mode voltage ramping in class D amplifiers for AM band transmission |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP3422588B1 (en) | Card detect architecture for near field communications | |
| US9461716B2 (en) | Near field communications (NFC) modulation feedback apparatus for tuned antenna configurations | |
| EP2721550B1 (en) | Contactless communication method with negative modulation | |
| EP3179639A1 (en) | A method and device for phase calibration with active load modulation | |
| DE102014204065A1 (en) | CONTACTLESS COMMUNICATION DEVICE AND USER DEVICE CONTAINING THEREOF | |
| EP3462370B1 (en) | Joint ad-hoc signal and collision detection method | |
| WO2001029753A1 (en) | Method for selecting and writing into rfid-transponders | |
| US20120057656A1 (en) | Method and apparatus for passive radio frequency indentification (rfid) reader digital demodulation for manchester subcarrier signal | |
| JP2006279813A (en) | Reader/writer | |
| CN104485894A (en) | Common-mode level shift treatment circuit and method for operational amplifier | |
| CN102457306B (en) | Analog front end circuit of interrogator in near field communication (NFC) system | |
| CN104156760B (en) | Electronic tag and detuner thereof | |
| CN104156740A (en) | Signal noise elimination method used for RFID, and device and circuit thereof | |
| EP2665019B1 (en) | Signal processing device, signal processing method, and receiving device | |
| CN104392193B (en) | Method and card reader that signal is filtered are received to RFID card reader | |
| EP2141637B1 (en) | Portable data carrier with active contactless interface and operating method | |
| CN101706879B (en) | Uhf reader demodulation circuit | |
| CN106897762A (en) | A kind of adaptive demodulation circuit and method for RFID label tag | |
| EP3667935A1 (en) | Method and system for operating a communications device that communicates via inductive coupling | |
| CN104332710A (en) | Method for designing high-performance antenna of RFID reader | |
| CN109327245A (en) | A kind of R-T unit and card reader | |
| CN103902945A (en) | Method for increasing identification rate of RFID label by adopting frequency-hopping scanning | |
| CN103870784A (en) | Method for detecting signal intensity of IQ circuit in RFID reader | |
| KR100910200B1 (en) | Method for detecting symbol in rfid system | |
| CN104218789A (en) | Voltage conversion circuit used for RFID (radio frequency identification) |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20150401 |
|
| RJ01 | Rejection of invention patent application after publication |