CN102651080A - Modulation circuit for noncontact IC (Integrated Circuit) card - Google Patents
Modulation circuit for noncontact IC (Integrated Circuit) card Download PDFInfo
- Publication number
- CN102651080A CN102651080A CN2011100458779A CN201110045877A CN102651080A CN 102651080 A CN102651080 A CN 102651080A CN 2011100458779 A CN2011100458779 A CN 2011100458779A CN 201110045877 A CN201110045877 A CN 201110045877A CN 102651080 A CN102651080 A CN 102651080A
- Authority
- CN
- China
- Prior art keywords
- modulation
- modulating unit
- card
- circuit
- unit
- 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
Images
Abstract
The invention discloses a modulation circuit for a noncontact IC (Integrated Circuit) card, which relates to the technical field of noncontact IC card communication. The modulation circuit comprises a positive modulation unit, a negative modulation unit and a modulation control unit, wherein the positive modulation unit is used for realizing load modulation on carrier waves; the negative modulation unit is used for realizing load modulation on the carrier waves; the modulation control unit is used for controlling the states of the positive modulation unit and the negative modulation unit, and outputting data to be transmitted to the positive modulation unit and the negative modulation unit; the positive modulation unit and the negative modulation unit are connected with the antenna end A and end B of the noncontact IC card respectively; and the modulation control unit is used for receiving a data signal and a modulation unit selection signal provided by an internal logic circuit, controlling the positive modulation unit through a positive modulation signal, and controlling the negative modulation unit through a negative modulation signal. The modulation circuit can work stably when the coupling field strength is relatively low, a relatively ideal state can be achieved within a largest working distance, and the working distance difference among different commands is avoided through power compensation.
Description
Technical field
The present invention relates to the contactless IC card communication technique field, especially for the modulation circuit of contactless IC card.
Background technology
Complete instruction cycle of contactless IC card can have three kinds of states successively: the data receiving state that receives the ASK instruction of read write line transmission; Receive a complete read write line instruction; And the instruction executing state of operating according to instruction, and the modulation condition of sending data to read write line.Contactless IC card sends to the data of read write line, generally realizes through the load-modulate mode.
In the prior art, common load-modulate mode has two kinds.A kind ofly can be called the forward load-modulate; The load-modulate circuit except that modulation condition At All Other Times; All be in off state, can between the antenna incoming end of contactless IC card, do not introduce load, and at needs when read write line sends data; The Data Control that the state of load-modulate circuit is sent by needs, corresponding two logic states of sending data of the shutoff of load-modulate circuit and conducting.Adopt the contactless IC card of forward load-modulate; Its advantage is that operating distance is farther relatively; But shortcoming is when near the critical operating distance of far-end, working, and antijamming capability is more weak, and when carrying out the instruction of different power consumption; Operating distance maybe be inconsistent farthest, and then influence the reliability of system works.Another kind of load-modulate mode can be called the negative sense load-modulate; The load-modulate circuit except that modulation condition At All Other Times; All be in conducting state, be equivalent between contactless IC card antenna side a and b load of parallel connection, at needs when read write line sends data; The Data Control that the state of load-modulate circuit is sent by needs equally, corresponding two logic states of sending data of the shutoff of load-modulate circuit and conducting.Adopt the negative sense load-modulate, contactless ic is stuck in the strong antijamming capability when smaller of coupled field and obviously improves, but cost is that operating distance can be affected farthest.
The energy of contactless IC card obtains through the inductive coupling mode, and its supply voltage must receive the influence of internal circuit power consumption, and when contactless IC card was carried out the instruction of different power consumption, tangible difference possibly appear in its supply voltage.If adopt aforesaid forward modulation scheme; The operating distance that then means the different power consumption instruction has significant difference, supposes that the maximum functional distance of power consumption minimum instruction is Dmax, and the maximum functional distance of the maximum instruction of power consumption is Dmin; Then in the Dmin-Dmax scope; Contactless IC card can not guarantee all reader instructions are all carried out smoothly, and when non-contact card was in this scope, some transaction possibly be interrupted in the process of carrying out.
Summary of the invention
In order to overcome the problem that exists in the above-mentioned prior art, the purpose of this invention is to provide a kind of modulation circuit that is used for contactless IC card.It promptly can guarantee can steady operation when smaller in the coupling field intensity, can guarantee that again operating distance reaches more satisfactory state farthest, simultaneously through to power consumption bigger instruction carry out power back-off, avoid the operating distance difference of different instruction.
In order to reach the foregoing invention purpose, technical scheme of the present invention realizes as follows:
A kind of modulation circuit that is used for contactless IC card is characterized in that, said circuit comprises:
Be used for carrier wave is realized the forward modulating unit of load-modulate;
Be used for carrier wave is realized the negative sense modulating unit of load-modulate;
Be used to control the state of forward modulating unit and negative sense modulating unit, and the data that will send output to the modulation control module of forward modulating unit and negative sense modulating unit.
The forward modulating unit links to each other with the antenna side a and b of contactless IC card respectively with the negative sense modulating unit.Data-signal and modulating unit that the modulation control module receives internal logic circuit to be provided are selected signal, and through forward modulation signal control forward modulating unit and through negative sense modulation signal control negative sense modulating unit.
In above-mentioned modulation circuit, said forward modulating unit comprises NMOS pipe one, and the negative sense modulating unit comprises NMOS pipe two, and the modulation control module is made up of two Sheffer stroke gates.
The present invention is used in combination forward modulation and back-modulation owing to adopted said structure, when contactless IC card is in data receiving state, through " negative sense modulating unit " load of parallel connection between contactless IC card antenna side a and b; When the instruction executing state, if the instruction power consumption is bigger, then turn-off " negative sense modulating unit " current drain when carrying out with compensating instruction, if the instruction power consumption is smaller, then " negative sense modulating unit " kept conducting state.The present invention is as long as select suitable " back-modulation unit " equivalent load, just can guarantee and only in the Dmin scope, all readers instruct all stablizes execution.Because when data receiving state, between contactless IC card antenna side a and b parallel connection load, when near the critical operating distance of far-end, working, its antijamming capability that receives data has certain enhancing.Compare with prior art; The present invention promptly can guarantee ability steady operation when the coupling field intensity is smaller; Can guarantee that again operating distance reaches more satisfactory state farthest, simultaneously through to power consumption bigger instruction carry out power back-off, avoid the operating distance difference of different instruction.
Below in conjunction with accompanying drawing and embodiment the present invention is further specified.
Description of drawings
Fig. 1 is a schematic diagram of the present invention;
Fig. 2 is a circuit diagram of the present invention;
Fig. 3 is when the instruction power consumption is bigger in the work of the present invention, command reception and execution simulation waveform synoptic diagram;
Fig. 4 is a kind of modulation condition simulation waveform synoptic diagram in the work of the present invention;
Fig. 5 is another kind of modulation condition simulation waveform synoptic diagram in the work of the present invention.
Embodiment
Referring to Fig. 1 and Fig. 2, modulation circuit of the present invention comprises: the forward modulating unit that is used for carrier wave is realized load-modulate; Be used for carrier wave is realized the negative sense modulating unit of load-modulate; Be used to control the state of forward modulating unit and negative sense modulating unit, and the data that will send output to the modulation control module of forward modulating unit and negative sense modulating unit.The forward modulating unit links to each other with B end PB_ANTENNA with the antenna A end PA_ANTENNA of contactless IC card respectively with the negative sense modulating unit.Data-signal TXD and modulating unit that the modulation control module receives internal logic circuit to be provided are selected signal MOD_SEL, and through forward modulation signal TXDP control forward modulating unit and through negative sense modulation signal TXDN control negative sense modulating unit.The forward modulating unit comprises that NMOS manages a MS_P, and the negative sense modulating unit comprises that NMOS manages two MS_N, and the modulation control module is made up of two Sheffer stroke gates.
Referring to Fig. 3, provided an instruction that power consumption is bigger, simulation waveform synoptic diagram from command reception to execution.The equivalent load of forward modulating unit and negative sense modulating unit is mainly managed the conduction impedance decision that a MS_P and NMOS manage two MS_N by NMOS among the present invention.After the contactless IC card electrification reset was accomplished, data-signal TXD=' 1 ' made forward modulator control signal TXDP=' 0 ', and the forward modulating unit is in off state; Modulating unit is selected signal MOD_SEL=' 0 ', makes back-modulation control signal TXDN=' 1 ', and the negative sense modulating unit is in conducting state; This configuration is maintained to contactless ic card receiver data mode and finishes.In the instruction executing state, if the instruction power consumption is bigger, then before beginning execution command; MOD_SEL puts ' 1 ', the negative sense modulating unit is turn-offed, with the current drain in the compensating instruction implementation; Instruct complete after; MOD_SEL reverts to ' 0 ' again, if the instruction power consumption is smaller, then MOD_SEL keeps ' 0 ' constant always.In the instruction executing state, it is ' 1 ' constant that TXD keeps.
Referring to Fig. 4, provided modulation condition simulation waveform synoptic diagram of the present invention.Send the modulation condition of data to reader at contactless IC card; MOD_SEL is at first by ' 0 ' saltus step ' 1 ', and at this moment, forward modulating unit and negative sense modulating unit are all controlled by TXD; The shutoff and the conducting of the logic ' 1 ' of TXD and logic ' 0 ' corresponding modulating circuit; Thereby realized the transmission of data, after data were sent completion, MOD_SEL reverted to ' 0 '.In some application system, in order to reach the purpose of better and reader communication, modulation condition also can use scheme shown in Figure 5 to realize.
Claims (2)
1. a modulation circuit that is used for contactless IC card is characterized in that, said circuit comprises:
Be used for carrier wave is realized the forward modulating unit of load-modulate;
Be used for carrier wave is realized the negative sense modulating unit of load-modulate;
Be used to control the state of forward modulating unit and negative sense modulating unit, and the data that will send output to the modulation control module of forward modulating unit and negative sense modulating unit;
The forward modulating unit links to each other with B end (PB_ANTENNA) with the antenna A end (PA_ANTENNA) of contactless IC card respectively with the negative sense modulating unit; Data-signal (TXD) and modulating unit that the modulation control module receives internal logic circuit to be provided are selected signal (MOD_SEL), and through forward modulation signal (TXDP) control forward modulating unit and through negative sense modulation signal (TXDN) control negative sense modulating unit.
2. the modulation circuit that is used for contactless IC card according to claim 1 is characterized in that, said forward modulating unit comprises NMOS pipe one (MS_P), and the negative sense modulating unit comprises NMOS pipe two (MS_N), and the modulation control module is made up of two Sheffer stroke gates.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011100458779A CN102651080A (en) | 2011-02-25 | 2011-02-25 | Modulation circuit for noncontact IC (Integrated Circuit) card |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011100458779A CN102651080A (en) | 2011-02-25 | 2011-02-25 | Modulation circuit for noncontact IC (Integrated Circuit) card |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN102651080A true CN102651080A (en) | 2012-08-29 |
Family
ID=46693084
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2011100458779A Pending CN102651080A (en) | 2011-02-25 | 2011-02-25 | Modulation circuit for noncontact IC (Integrated Circuit) card |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN102651080A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107067063A (en) * | 2016-01-20 | 2017-08-18 | 恩智浦有限公司 | intelligent electronic device |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101385040A (en) * | 2005-12-15 | 2009-03-11 | Nxp股份有限公司 | Radio frequency interface circuit for a radio frequency identification tag |
| CN101436260A (en) * | 2007-11-16 | 2009-05-20 | 株式会社瑞萨科技 | Data processing circuit and communication mobile terminal device |
| CN202084063U (en) * | 2011-02-25 | 2011-12-21 | 北京同方微电子有限公司 | Modulation circuit used for non-contact IC card |
-
2011
- 2011-02-25 CN CN2011100458779A patent/CN102651080A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101385040A (en) * | 2005-12-15 | 2009-03-11 | Nxp股份有限公司 | Radio frequency interface circuit for a radio frequency identification tag |
| CN101436260A (en) * | 2007-11-16 | 2009-05-20 | 株式会社瑞萨科技 | Data processing circuit and communication mobile terminal device |
| CN202084063U (en) * | 2011-02-25 | 2011-12-21 | 北京同方微电子有限公司 | Modulation circuit used for non-contact IC card |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107067063A (en) * | 2016-01-20 | 2017-08-18 | 恩智浦有限公司 | intelligent electronic device |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN201830468U (en) | Non-contact communication terminal | |
| CN201878132U (en) | Mobile terminal | |
| CN101582759A (en) | Detection of data received by a master device in a single-wire communication protocol | |
| CN105099527A (en) | Passive Near Field Communication (NFC) communication interface having independent energy receiving antenna | |
| CN101236453A (en) | Connection structure and communicating method between NFC control chip and SIM card chip | |
| CN100576770C (en) | The control device of array antenna | |
| CN104052519A (en) | Duplex antenna applied to BTM system, transponder information reading method and BTM self-checking method | |
| CN105306105B (en) | Telecommunication circuit and communication means with modulation | |
| CN101916950A (en) | Safety chip concentrator | |
| CN104101866A (en) | Pulse modulating system of radar system | |
| CN102339266B (en) | Single data line bidirectional dual voltage communication interface circuit | |
| CN104331733A (en) | Ultrahigh-frequency RFID label and anti-interference method thereof | |
| CN104239833A (en) | Low-power-consumption card reader and using method thereof | |
| CN202084063U (en) | Modulation circuit used for non-contact IC card | |
| CN101753722A (en) | Interface circuit meeting single wire protocol (SWP) on subscriber identity module (SIM) card chip | |
| CN102651080A (en) | Modulation circuit for noncontact IC (Integrated Circuit) card | |
| CN104091722A (en) | Relay drive circuit | |
| CN205028302U (en) | A object that is used for equipment of operation of management object and includes this equipment | |
| CN211405621U (en) | NFC-based power supply circuit and passive electronic terminal with same | |
| CN201508570U (en) | Non-contact intelligent module and intelligent card | |
| CN105868810A (en) | NFC reader-writer interface for optimizing energy acquisition and mini antenna | |
| CN205263303U (en) | Burden voltage pulse modulated circuit | |
| CN102255638B (en) | Interface circuit meeting single wire protocol (SWP) on contactless front (CLF) chip of near field communication (NFC) controller | |
| CN205160520U (en) | Passive NFC communication interface with independent energy receiving antenna | |
| CN203086471U (en) | Network NFC (Near Field Communication) equipment |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C02 | Deemed withdrawal of patent application after publication (patent law 2001) | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20120829 |