CN201044355Y - ESD protection circuit and circuit for preventing reverse power supply of ESD protective circuit - Google Patents
ESD protection circuit and circuit for preventing reverse power supply of ESD protective circuit Download PDFInfo
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- CN201044355Y CN201044355Y CNU2007201203598U CN200720120359U CN201044355Y CN 201044355 Y CN201044355 Y CN 201044355Y CN U2007201203598 U CNU2007201203598 U CN U2007201203598U CN 200720120359 U CN200720120359 U CN 200720120359U CN 201044355 Y CN201044355 Y CN 201044355Y
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- diode
- esd protection
- protection circuit
- power supply
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Abstract
The utility model provides a circuit for preventing reverse power supply of ESD protective circuit, which is provided with a unidirectional conduction module or a voltage dividing module between the ESD protective circuit and a power. Reverse current is stopped by the unidirectional conduction module, and high reverse level is divided by the voltage-dividing module, thereby the external equipment is effectively prevented from using the ESD protective circuit to supply power reversely to the main equipment via a high-speed signal line when the main equipment is power-off. The utility model also provides an ESD protective circuit, in which a unidirectional conduction module or a voltage dividing module is serially connected with the cathodes of a second diode and a zener diode and then connected with the power on the basis of the prior ESD protective circuit. Reverse current is stopped by the unidirectional conduction module, and high reverse level is divided by the voltage-dividing module, thereby the external equipment is effectively prevented from using the ESD protective circuit to supply power reversely to the main equipment via a high-speed signal line when the main equipment is power-off.
Description
Technical field
The utility model relates to the technical field that prevents reverse power supply in the electronic product, especially relates to a kind of esd protection circuit and prevents the reverse power supply circuits of esd protection circuit.
Background technology
Be accompanied by the continuous development of electronic application requirement in recent years; static discharge (Electro Static Discharge; ESD) the protection problem becomes more and more important; increasing semiconductor manufacturer is devoted to this; particularly at the esd protection of high speed interface, as USB, IEEE1394, HDMI, DVI and ESATA interface etc.Present general ESD device is general inner to adopt the diode array structure design, utilizes up and down diode (or TVS in parallel pipe, help sparking) conducting to realize that electric charge discharges, and reaches the effect of esd protection.(is example with the one-channel signal esd protection) as shown in Figure 1; its internal structure mainly comprises the first diode D1, the second diode D2, voltage stabilizing didoe Z1; it is in parallel after the first diode D1 connects with the second diode D2 with voltage stabilizing didoe Z1; the first diode D1 anode and voltage stabilizing didoe Z1 plus earth; the second diode D2 negative electrode and voltage stabilizing didoe Z1 negative electrode connect power supply; this kind esd protection circuit simplicity of design; safe and efficient for esd protection, but have very big hidden danger for other circuit of system.With set-top box HDMI interface esd protection circuit is example, and as shown in Figure 2, its TMDS differential signal SINK end is inner to be pulled to 3.3V (referring to High-Definition Multimedia Interface Specification Version 1.1) by 50 Europe resistance.Equipment (as set-top box) outage when band HDMI interface, connected HDMI interface equipment (as television set) is when still working, ancillary equipment can be by the HW High Way 3.3V that oppositely powers, and input to the power supply VCC loop of set-top box by the diode of conducting ESD chip internal, can cause other circuit module non-normal working of the inner shared VCC power supply of set-top box, cause chip circuit to damage when serious; When set-top box re-powers, also may cause set-top box normally not start owing to the confusion of its builtin voltage electrifying timing sequence.
The utility model content
Technical problem to be solved in the utility model provides a kind of reverse power supply circuits of esd protection circuit that prevent, it can prevent that under the main equipment powering-off state, external equipment utilizes esd protection circuit oppositely to power to main equipment by HW High Way.
For solving technical problem of the present utility model, the utility model discloses a kind of reverse power supply circuits of esd protection circuit that prevent, it is unidirectional conduction module or the division module that is serially connected with between esd protection circuit and the power supply.
Wherein said unidirectional conduction module is that anode connects power supply, and negative electrode connects the diode of esd protection circuit.
Wherein said unidirectional conduction module is a triode, and its base stage connects described power supply, and collector electrode draws level on connecting, and emitter connects esd protection circuit.
Wherein said division module is any circuit module that can reduce to feed back to the reverse voltage of power end, and typical circuit is serial connection one resistance.
Another technical problem to be solved in the utility model provides a kind of esd protection circuit, and it can prevent that under the main equipment powering-off state, external equipment utilizes esd protection circuit oppositely to power to main equipment by HW High Way.
For solving technical problem of the present utility model; the utility model discloses a kind of esd protection circuit; it comprises first diode, second diode, voltage stabilizing didoe; it is in parallel after first diode is connected with second diode with voltage stabilizing didoe; first diode anode and voltage stabilizing didoe plus earth; second diode cathode and voltage stabilizing didoe negative electrode connect power supply, described second diode cathode be connected power supply after the voltage stabilizing didoe negative electrode is connected in series unidirectional conduction module or division module.
Wherein said unidirectional conduction module is that anode connects power supply, and negative electrode connects the diode of second diode cathode and voltage stabilizing didoe negative electrode.
Wherein said unidirectional conduction module is a triode, and its base stage connects described power supply, and collector electrode draws level on connecting, and emitter connects described second diode cathode and voltage stabilizing didoe negative electrode.
Wherein said division module is a resistance.
Compared with prior art; the utlity model has following beneficial effect: the utility model is by being provided with a unidirectional conducting or a division module between esd protection circuit and main equipment power supply; prevent that effectively external equipment under the main equipment powering-off state, utilizing esd protection circuit oppositely to power to main equipment by HW High Way.
Description of drawings
Fig. 1 is the esd protection circuit figure of prior art;
Fig. 2 be in the prior art external equipment by the esd protection circuit design sketch (is example with the HDMI interface) of oppositely powering;
Fig. 3 is the esd protection circuit schematic diagram of the utility model embodiment 1;
Fig. 4 is the esd protection circuit concrete structure figure of the utility model embodiment 1;
Fig. 5 is the esd protection circuit concrete structure figure of the utility model embodiment 1;
Fig. 6 is the esd protection circuit schematic diagram of the utility model embodiment 2;
Fig. 7 is the esd protection circuit concrete structure figure of the utility model embodiment 2.
Embodiment
Below in conjunction with drawings and Examples, the utility model is described in further detail.
As shown in Figure 3, the utility model can prevent effectively that by increase by the one unidirectional conduction module between esd protection circuit and power supply external equipment under the main equipment powering-off state, utilizing esd protection circuit oppositely to power to main equipment by HW High Way.
In addition, this unidirectional conduction module also can be encapsulated in the chip with esd protection circuit, as a new esd protection circuit.
As shown in Figure 4; present embodiment adopts diode D3 as unidirectional conduction module; seal in diode D3 at the VCC of esd protection circuit power input; its negative electrode connects the negative electrode of the second diode D2 and voltage stabilizing didoe Z1; its anode connects the VCC power supply; diode D3 can adopt Schottky diode, TVS diode, should not be lower than under the reverse electric power thus supplied of external equipment by the voltage behind the D2 as long as guarantee its reverse breakdown voltage, and its forward conduction voltage drop is not too big.
Operation principle is as follows:
During the circuit operate as normal since add diode D3 reverse operation pattern under high pressure, the esd protection performance is not affected; When the main equipment outage, though the high level that external equipment transmits by HW High Way can conducting at the second diode D2 place, but, make it to flow into main equipment VCC electric power loop, thereby reach the effect that does not influence the main equipment circuit because diode D3's is reverse by function.
As shown in Figure 5; present embodiment adopts triode Q1 as unidirectional conduction module again; seal in triode Q1 at the VCC of esd protection circuit power input; its base stage connects the VCC power supply; collector electrode draws+the 5V level on connecting, and emitter connects the second diode D2 negative electrode and the voltage stabilizing didoe Z1 negative electrode of esd protection circuit.
Operation principle is as follows:
When the main equipment outage, though the high level that external equipment transmits by HW High Way can conducting at the second diode D2 place, but, make it to flow into main equipment VCC electric power loop, thereby reach the effect that does not influence the main equipment circuit because triode Q1's is reverse by function.
As shown in Figure 6, the utility model can effectively suppress reverse supply power voltage by increase by one division module between esd protection circuit and power supply, and this division module also can be encapsulated in the chip with esd protection circuit, as a new esd protection circuit.
As shown in Figure 7, present embodiment adopts resistance R 1 as division module, and its resistance can be determined according to actual conditions.
Operation principle is as follows:
During the circuit operate as normal, the esd protection performance is not affected; When the main equipment outage, the high level that external equipment transmits by HW High Way passes through the dividing potential drop effect of resistance R 1, and the voltage that feeds back to power supply VCC loop reduces greatly, thereby reaches the effect that does not influence the main equipment circuit.
The protection that the utility model is oppositely powered and carried out by esd protection circuit for external equipment, its outstanding effect shows the following aspects:
1, prevents the component wear that causes because of reverse power supply;
2, prevent that the main equipment electrifying timing sequence confusion, the startup that cause because oppositely powering are unusual;
3, prevent main equipment electric energy loss because oppositely powering and cause under powering-off state.
Claims (10)
1. one kind prevents the reverse power supply circuits of esd protection circuit, it is characterized in that: it is unidirectional conduction module or the division module that is serially connected with between esd protection circuit and the power supply.
2. the reverse power supply circuits of esd protection circuit that prevent as claimed in claim 1 is characterized in that: described unidirectional conduction module is that anode connects power supply, and negative electrode connects the diode of esd protection circuit.
3. the reverse power supply circuits of esd protection circuit that prevent as claimed in claim 2, it is characterized in that: described diode can adopt Schottky diode, TVS diode.
4. the reverse power supply circuits of esd protection circuit that prevent as claimed in claim 1, it is characterized in that: described unidirectional conduction module is a triode, and its base stage connects described power supply, and collector electrode draws level on connecting, and emitter connects esd protection circuit.
5. the reverse power supply circuits of esd protection circuit that prevent as claimed in claim 1, it is characterized in that: described division module is a resistance.
6. esd protection circuit; it comprises first diode, second diode, voltage stabilizing didoe; it is in parallel after first diode is connected with second diode with voltage stabilizing didoe; first diode anode and voltage stabilizing didoe plus earth; second diode cathode and voltage stabilizing didoe negative electrode connect power supply, it is characterized in that: described second diode cathode be connected power supply after the voltage stabilizing didoe negative electrode is connected in series unidirectional conduction module or division module.
7. esd protection circuit as claimed in claim 6 is characterized in that: described unidirectional conduction module is that anode connects power supply, and negative electrode connects the diode of second diode cathode and voltage stabilizing didoe negative electrode.
8. esd protection circuit as claimed in claim 7 is characterized in that: described diode can adopt Schottky diode, TVS diode.
9. esd protection circuit as claimed in claim 6 is characterized in that: described unidirectional conduction module is a triode, and its base stage connects described power supply, and collector electrode draws level on connecting, and emitter connects described second diode cathode and voltage stabilizing didoe negative electrode.
10. esd protection circuit as claimed in claim 6 is characterized in that: described division module is a resistance.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU2007201203598U CN201044355Y (en) | 2007-05-24 | 2007-05-24 | ESD protection circuit and circuit for preventing reverse power supply of ESD protective circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU2007201203598U CN201044355Y (en) | 2007-05-24 | 2007-05-24 | ESD protection circuit and circuit for preventing reverse power supply of ESD protective circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN201044355Y true CN201044355Y (en) | 2008-04-02 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNU2007201203598U Expired - Fee Related CN201044355Y (en) | 2007-05-24 | 2007-05-24 | ESD protection circuit and circuit for preventing reverse power supply of ESD protective circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN201044355Y (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102025137A (en) * | 2009-09-21 | 2011-04-20 | 群康科技(深圳)有限公司 | Electrostatic discharge protection circuit and electronic device with same |
| CN103022996A (en) * | 2011-09-21 | 2013-04-03 | 中芯国际集成电路制造(北京)有限公司 | Electronic static discharge protection circuit and electronic static discharge protection method |
| CN103248034A (en) * | 2013-05-15 | 2013-08-14 | 成都市宏山科技有限公司 | Lightning protection USB flash disk |
| CN105703345A (en) * | 2014-11-26 | 2016-06-22 | 鸿富锦精密工业(武汉)有限公司 | USB electrostatic protection circuit |
| CN107616693A (en) * | 2016-07-14 | 2018-01-23 | 广东美的生活电器制造有限公司 | The power supply circuit of electric hot water bottle |
-
2007
- 2007-05-24 CN CNU2007201203598U patent/CN201044355Y/en not_active Expired - Fee Related
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102025137A (en) * | 2009-09-21 | 2011-04-20 | 群康科技(深圳)有限公司 | Electrostatic discharge protection circuit and electronic device with same |
| CN102025137B (en) * | 2009-09-21 | 2013-08-21 | 群康科技(深圳)有限公司 | Electrostatic discharge protection circuit and electronic device with same |
| CN103022996A (en) * | 2011-09-21 | 2013-04-03 | 中芯国际集成电路制造(北京)有限公司 | Electronic static discharge protection circuit and electronic static discharge protection method |
| CN103022996B (en) * | 2011-09-21 | 2015-02-11 | 中芯国际集成电路制造(北京)有限公司 | Electronic static discharge protection circuit and electronic static discharge protection method |
| CN103248034A (en) * | 2013-05-15 | 2013-08-14 | 成都市宏山科技有限公司 | Lightning protection USB flash disk |
| CN103248034B (en) * | 2013-05-15 | 2015-08-12 | 成都市宏山科技有限公司 | Can the USB flash disk of lightning protection |
| CN105703345A (en) * | 2014-11-26 | 2016-06-22 | 鸿富锦精密工业(武汉)有限公司 | USB electrostatic protection circuit |
| CN107616693A (en) * | 2016-07-14 | 2018-01-23 | 广东美的生活电器制造有限公司 | The power supply circuit of electric hot water bottle |
| CN107616693B (en) * | 2016-07-14 | 2022-10-14 | 广东美的生活电器制造有限公司 | Power supply circuit of electric thermos bottle |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C56 | Change in the name or address of the patentee | ||
| CP03 | Change of name, title or address |
Address after: Rainbow science and Technology Building (North West Road), north of Nanshan District Science Park, Guangdong, Shenzhen Province, China: 518057 Patentee after: Shenzhen Tongzhou Electronic Co., Ltd. Address before: W2-A7 building, hi tech park, Shennan Avenue, Shenzhen, Guangdong, Nanshan District 518057, China Patentee before: Shenzhen Tongzhou Electronic Co., Ltd. |
|
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20080402 Termination date: 20150524 |
|
| EXPY | Termination of patent right or utility model |