CN101789984B - SIM card interface circuit and mobile phone - Google Patents
SIM card interface circuit and mobile phone Download PDFInfo
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- CN101789984B CN101789984B CN 200910239081 CN200910239081A CN101789984B CN 101789984 B CN101789984 B CN 101789984B CN 200910239081 CN200910239081 CN 200910239081 CN 200910239081 A CN200910239081 A CN 200910239081A CN 101789984 B CN101789984 B CN 101789984B
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- sim card
- baseband chip
- analog switch
- card slot
- mobile phone
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Abstract
Belonging to the field of communication, the embodiment of the invention provides an SIM card interface circuit and a mobile phone. The interface circuit comprises an SIM card guide, a baseband chip used for outputting switch connection signals, an electrostatic leakage circuit used for leaking electrostatic charge generated by the SIM card guide; wherein an analogue switch is connected with the SIM card guide, the baseband chip and the electrostatic leakage circuit and is used for connecting the baseband chip or communicating with the baseband chip and the SIM card guide when being controlled by the switch connection signals for leaking the electrostatic charge generated by the SIM card guide; an ESD protective element is connected to a connection network between the SIM card guide and the analogue switchfor leaking the electrostatic charge generated by the SIM card guide when a battery is not connected to the mobile phone. With the SIM card interface circuit and the mobile phone, electrostatic discharge generated when the SIM card is plugged or the circuit operates after being electrified can be eliminated, so that the baseband chip of the mobile phone can be effectively protected.
Description
Technical field
The invention belongs to the communications field, relate in particular to a kind of SIM card interface circuit and mobile phone.
Background technology
At present, mobile phone normally SIM card interface directly links to each other with baseband chip, adds static on each port and discharges (Electro-Static discharge, ESD) element protection.In SIM card plug process, the hard contact friction of SIM card and sim card slot is easy to produce static discharge, even the ESD element protection is arranged, also can damage baseband chip sometimes.Simultaneously, can store a lot of electrostatic charges on the metal terminal on the sim card slot, when circuit works on power, also may cause damage to baseband chip.
Summary of the invention
The purpose of the embodiment of the invention is to provide a kind of SIM card interface circuit, is intended to solve existing SIM interface circuit in SIM card plug process, and circuit is when working on power, and sim card slot produces electrostatic charge, damages the problem of baseband chip easily.
The embodiment of the invention is achieved in that a kind of SIM card interface circuit, comprises sim card slot, and described interface circuit also comprises:
Baseband chip is used for the output switch and connects signal;
Static leakage circuit is for the electrostatic charge of the described sim card slot generation of releasing;
Analog switch, with described sim card slot, baseband chip, and static leakage circuit connects, be used for connecting under the control of signal at described switch, be connected with described baseband chip, be communicated with described baseband chip and sim card slot, perhaps be connected with described static leakage circuit, the electrostatic charge that the described sim card slot of releasing produces; And
The esd protection element is connected to being connected on the network between described sim card slot and the analog switch, is used for when battery does not insert mobile phone the electrostatic charge that the described sim card slot of releasing produces;
Wherein, described analog switch comprises: first analog switch, and second analog switch;
One end of described first analog switch and second analog switch links to each other with the output control network of described baseband chip respectively.
Another purpose of the embodiment of the invention is to provide a kind of mobile phone that comprises above-mentioned SIM card interface circuit.
Another purpose of the embodiment of the invention is to provide a kind of mobile phone, comprises sim card slot, and described mobile phone also comprises:
The switch linkage unit is used for output switch link order;
Baseband chip is used for connecting signal according to described switch link order output switch;
Static leakage circuit is for the electrostatic charge of the described sim card slot generation of releasing;
Analog switch, with described sim card slot, baseband chip, and static leakage circuit connects, be used for connecting under the control of signal at described switch, be connected with described baseband chip, be communicated with described baseband chip and sim card slot, perhaps be connected with described static leakage circuit, the electrostatic charge that the described sim card slot of releasing produces; And
The esd protection element is connected to being connected on the network between described sim card slot and the analog switch, is used for when battery does not insert mobile phone the electrostatic charge that the described sim card slot of releasing produces;
Wherein, described analog switch comprises: first analog switch, and second analog switch;
One end of described first analog switch and second analog switch links to each other with the output control network of described baseband chip respectively.
The embodiment of the invention utilizes analog switch that direct-connected SIM card and baseband chip are isolated; be connected with baseband chip or static leakage circuit by the software control analog switch; do not influencing on the normal connection basis of sim card slot and baseband chip; by the static leakage circuit electrostatic charge that sim card slot produces of releasing; produce the problem that static discharge damages baseband chip when elimination plugs because of SIM card and circuit works on power; can effectively protect the baseband chip of mobile phone; even if static discharge causes the damage of analog switch, its maintenance cost also is significantly less than the maintenance cost that baseband chip damages.
Description of drawings
Fig. 1 is the structure principle chart of the SIM card interface circuit that provides of the embodiment of the invention;
Fig. 2 is the structure chart of the SIM card interface circuit that provides of the embodiment of the invention.
Embodiment
In order to make purpose of the present invention, technical scheme and advantage clearer, below in conjunction with drawings and Examples, the present invention is further elaborated.Should be appreciated that specific embodiment described herein only in order to explaining the present invention, and be not used in restriction the present invention.
The embodiment of the invention utilizes analog switch that direct-connected SIM card and baseband chip are isolated, be connected with baseband chip or static leakage circuit by the software control analog switch, do not influencing on the normal connection basis of sim card slot and baseband chip, by the static leakage circuit electrostatic charge that sim card slot produces of releasing.
Fig. 1 shows the structural principle of the SIM card interface circuit that the embodiment of the invention provides, and for convenience of explanation, only shows the part relevant with the embodiment of the invention.
SIM card interface circuit 2 can be widely used in the various mobile phones, comprises parts such as baseband chip 21, analog switch 22, sim card slot 23, static leakage circuit 24, esd protection element 25.
The software unit of switching on and shutting down control unit 1 for having switching on and shutting down control function in the mobile phone, output switch link order, control baseband chip 21 output switches connect signals, and control analog switch 22 or be connected with baseband chip 21 perhaps is connected with static leakage circuit 5.
In embodiments of the present invention, switch in baseband chip 21 outputs connects under the control of signal, analog switch 22 both can be connected baseband chip 21 with sim card slot 23, realize that baseband chip 21 is connected with the normal of sim card slot 23, also sim card slot 23 can be connected with static leakage circuit 24, the electrostatic charge that produces is released by static leakage circuit 24.
In the real work, when battery did not insert mobile phone, analog switch 22 was not worked because of outage.At this moment, the electrostatic charge that produces owing to the plug SIM card on sim card slot 23 discharges by esd protection element 25.When mobile phone worked on power, switching on and shutting down control unit 1 control baseband chip 21 output switches connected signal, and control analog switch 22 is connected with static leakage circuit 24, by static leakage circuit 24 electrostatic charge that sim card slot 23 produces is released.After mobile phone worked on power, switching on and shutting down control unit 1 control baseband chip 21 output switches connected signal, and control analog switch 22 is connected with baseband chip 21, thereby realizes that baseband chip 21 is connected with the normal of sim card slot 23.When mobile phone turn-off, switching on and shutting down control unit 1 control baseband chip 21 output switches connect signals, the disconnection that is connected of control analog switch 22 and baseband chip 21, and reach the effect of protecting group microarray strip 21.
Fig. 2 shows the structure of the SIM card interface circuit that the embodiment of the invention provides, and for convenience of explanation, only shows the part relevant with the embodiment of the invention.
In embodiments of the present invention, switching on and shutting down control unit 1 can be exported the switch link order, the operating state of the output control network C TR_SIM of control baseband chip 21.
The influence of static when eliminating switching on and shutting down, design switching on and shutting down control unit 1 is when mobile phone works on power, the output control network C TR_SIM output low level of control baseband chip 21, control analog switch 22 is connected with static leakage circuit 24, and the electrostatic charge on the sim card slot 23 is released by static leakage circuit 24.
After mobile phone works on power, the output control network C TR_SIM output high level of switching on and shutting down control unit 1 control baseband chip 21, control analog switch 22 is connected with sim card slot 23, thereby realizes that baseband chip 21 is connected with the normal of sim card slot 23.
During mobile phone turn-off; the output control network C TR_SIM output low level of switching on and shutting down control unit 1 control baseband chip 21; the disconnection that is connected of control analog switch 22 and baseband chip 21, isolation baseband chip 21 and sim card slot 23 reach the effect of protecting group microarray strip 21.
The operating voltage of analog switch 22 is VCC, by the battery-powered operation of mobile phone.When not having operating voltage, analog switch 22 output high-impedance states.
In embodiments of the present invention, analog switch 22 is made up of two groups of switch U1, U2, by the output control network C TR_SIM control of baseband chip 21.When the output control network C TR_SIM of baseband chip 21 output low level, analog switch 22 is connected with static leakage circuit 5, and when the output control network C TR_SIM of baseband chip 21 output high level, analog switch 22 is connected with baseband chip 21.
As one embodiment of the present of invention, static leakage circuit 24 comprises four resistance R 1, R2, R3, R4.The end of resistance R 1, R2 altogether, the other end links to each other with analog switch U1 respectively.The end of resistance R 3, R4 altogether, the other end links to each other with analog switch U2 respectively.After analog switch 22 is connected to static leakage circuit 24, bleeder resistance can with sim card slot 23 that analog switch 22 links to each other on electrostatic leakage on the ground.
In Fig. 2, resistance R 5 is that the periphery of sim card slot 23 connects resistance.
In plug SIM card process; SIM card and the friction of sim card slot hard contact can produce static discharge; and the battery of mobile phone also pulls out in this process; in the case; analog switch 22 is not worked; therefore supply voltage network SIM_VCC, reseting network SIM_RST, clock network SIM_CLK, the data network SIM_DATA of sim card slot 23 are high-impedance state, and electrostatic charge can only be by the TVS diode D1 in the esd protection element 25, D2, D3, D4 discharge.And in this case, supply voltage network SIM_VCC1, the reseting network SIM_RST1 of baseband chip 21, clock network SIM_CLK1, data network SIM_DATA1 just go up and do not exist static to discharge problem.
When battery operated on the mobile phone, output control network C TR_SIM output low level in the switching on and shutting down control unit 1 control baseband chip 21, supply voltage network SIM_VCC, reseting network SIM_RST, clock network SIM_CLK, data network SIM_DATA and bleeder resistance R1, the R2 of baseband chip 21, R3, R4 connect, and the electrostatic charge that the metal terminal on the sim card slot 23 exists will be released on the ground by four bleeder resistance R1, R2, R3, R4.
After the electrostatic charge when switching on and shutting down control unit 1 has been released sim card slot 23 via the output control network C TR_SIM control analog switch 22 of baseband chip 21 on, the output control network C TR_SIM output high level of switching on and shutting down control unit 1 control baseband chip 21, make the supply voltage network SIM_VCC of sim card slot 23, reseting network SIM_RST, clock network SIM_CLK, the supply voltage network SIM_VCC1 of data network SIM_DATA and baseband chip 21, reseting network SIM_RST1, clock network SIM_CLK1, data network SIM_DATA1 connects, thereby realizes the normal connection of baseband chip 21 and sim card slot 23.
When mobile phone turn-off, need the output control network C TR_SIM output low level of switching on and shutting down control unit 1 control baseband chip 21 equally, make 23 of baseband chip 21 and sim card slots be electrically connected disconnection, and reach the effect of protecting group microarray strip 21.
The embodiment of the invention utilizes analog switch that direct-connected SIM card and baseband chip are isolated; be connected with baseband chip or static leakage circuit by the software control analog switch; do not influencing on the normal connection basis of sim card slot and baseband chip; by the static leakage circuit electrostatic charge that sim card slot produces of releasing; produce the problem that static discharge damages baseband chip when elimination plugs because of SIM card and circuit works on power; can effectively protect the baseband chip of mobile phone; even if static discharge causes the damage of analog switch, its maintenance cost also is significantly less than the maintenance cost that baseband chip damages.
The above only is preferred embodiment of the present invention, not in order to limiting the present invention, all any modifications of doing within the spirit and principles in the present invention, is equal to and replaces and improvement etc., all should be included within protection scope of the present invention.
Claims (7)
1. a SIM card interface circuit comprises sim card slot, it is characterized in that, described interface circuit also comprises:
Baseband chip is used for the output switch and connects signal;
Static leakage circuit is for the electrostatic charge of the described sim card slot generation of releasing;
Analog switch, with described sim card slot, baseband chip, and static leakage circuit connects, be used for connecting under the control of signal at described switch, be connected with described baseband chip, be communicated with described baseband chip and sim card slot, perhaps be connected with described static leakage circuit, the electrostatic charge that the described sim card slot of releasing produces; And
The esd protection element is connected to being connected on the network between described sim card slot and the analog switch, is used for when battery does not insert mobile phone the electrostatic charge that the described sim card slot of releasing produces;
Wherein, described analog switch comprises: first analog switch, and second analog switch;
One end of described first analog switch and second analog switch links to each other with the output control network of described baseband chip respectively.
2. circuit as claimed in claim 1, it is characterized in that, when mobile phone worked on power, described analog switch was connected the electrostatic charge that the described sim card slot of releasing produces with described static leakage circuit under the control of the respective switch connection signal of described baseband chip output;
After mobile phone worked on power, described analog switch was connected with described baseband chip under the control of the respective switch connection signal of described baseband chip output, normally connects described sim card slot and baseband chip;
When mobile phone turn-off, described analog switch is connected with described baseband chip disconnection under the control of the respective switch connection signal of described baseband chip output.
3. circuit as claimed in claim 2 is characterized in that, described static leakage circuit comprises first resistance, second resistance, the 3rd resistance and the 4th resistance;
One end of described first and second resistance altogether, the other end links to each other with described first analog switch respectively;
One end of described third and fourth resistance altogether, the other end links to each other with described second analog switch respectively.
4. mobile phone that comprises the described SIM card interface circuit of claim 1.
5. a mobile phone comprises sim card slot, it is characterized in that, described mobile phone also comprises:
The switch linkage unit is used for output switch link order;
Baseband chip is used for connecting signal according to described switch link order output switch;
Static leakage circuit is for the electrostatic charge of the described sim card slot generation of releasing;
Analog switch, with described sim card slot, baseband chip, and the static leakage circuit connection, be used for connecting under the control of signal at described switch, be connected with described baseband chip or static leakage circuit; And
The esd protection element is connected to being connected on the network between described sim card slot and the analog switch, is used for when battery does not insert mobile phone the electrostatic charge that the described sim card slot of releasing produces;
Wherein, described analog switch comprises: first analog switch, and second analog switch;
One end of described first analog switch and second analog switch links to each other with the output control network of described baseband chip respectively.
6. mobile phone as claimed in claim 5, it is characterized in that, when mobile phone worked on power, described analog switch was connected the electrostatic charge that the described sim card slot of releasing produces with static leakage circuit under the control of the respective switch connection signal of described baseband chip output;
After mobile phone worked on power, described analog switch was connected with described baseband chip under the control of the respective switch connection signal of described baseband chip output, realizes that described sim card slot is connected with the normal of baseband chip;
When mobile phone turn-off, described analog switch is connected with described baseband chip disconnection under the control of the respective switch connection signal of described baseband chip output.
7. mobile phone as claimed in claim 5 is characterized in that, described static leakage circuit comprises first resistance, second resistance, the 3rd resistance and the 4th resistance;
One end of described first and second resistance altogether, the other end links to each other with described first analog switch respectively;
One end of described third and fourth resistance altogether, the other end links to each other with described second analog switch respectively.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200910239081 CN101789984B (en) | 2009-12-28 | 2009-12-28 | SIM card interface circuit and mobile phone |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200910239081 CN101789984B (en) | 2009-12-28 | 2009-12-28 | SIM card interface circuit and mobile phone |
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| Publication Number | Publication Date |
|---|---|
| CN101789984A CN101789984A (en) | 2010-07-28 |
| CN101789984B true CN101789984B (en) | 2013-09-25 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 200910239081 Active CN101789984B (en) | 2009-12-28 | 2009-12-28 | SIM card interface circuit and mobile phone |
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Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102427498A (en) * | 2011-08-04 | 2012-04-25 | 广东欧珀移动通信有限公司 | Method of eliminating interference of ESD (Electro-Static discharge) on T card of mobile phone |
| CN105630722B (en) * | 2015-12-21 | 2019-03-08 | 联想(北京)有限公司 | Electronic equipment and signal processing method |
| CN108173560A (en) * | 2018-01-31 | 2018-06-15 | 维沃移动通信有限公司 | A kind of deck anti-static circuit and electronic equipment |
| CN111525939B (en) * | 2020-04-13 | 2021-09-17 | 重庆蓝岸通讯技术有限公司 | SD card protection system and method and protection circuit for multi-card-slot-in-one connector |
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| CN1885979A (en) * | 2006-06-16 | 2006-12-27 | 海信集团有限公司 | Dual-mode dual-standby mobile phone with dual-slot and its realizing method |
| CN1985370A (en) * | 2004-07-13 | 2007-06-20 | 皇家飞利浦电子股份有限公司 | Electronic device comprising an ESD device |
| CN101483339A (en) * | 2009-01-06 | 2009-07-15 | 深圳市明微电子股份有限公司 | Electrostatic protection method and circuit having detection control circuit |
| CN201323446Y (en) * | 2008-12-01 | 2009-10-07 | 闻泰集团有限公司 | Static-free handheld mobile device with soft USB function |
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2009
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Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1985370A (en) * | 2004-07-13 | 2007-06-20 | 皇家飞利浦电子股份有限公司 | Electronic device comprising an ESD device |
| CN1885979A (en) * | 2006-06-16 | 2006-12-27 | 海信集团有限公司 | Dual-mode dual-standby mobile phone with dual-slot and its realizing method |
| CN201323446Y (en) * | 2008-12-01 | 2009-10-07 | 闻泰集团有限公司 | Static-free handheld mobile device with soft USB function |
| CN101483339A (en) * | 2009-01-06 | 2009-07-15 | 深圳市明微电子股份有限公司 | Electrostatic protection method and circuit having detection control circuit |
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| CN101789984A (en) | 2010-07-28 |
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