CN1741342A

CN1741342A - Electrostatic protector for multi-voltage source system

Info

Publication number: CN1741342A
Application number: CN 200410057909
Authority: CN
Inventors: 吕昭信
Original assignee: Realtek Semiconductor Corp
Current assignee: Realtek Semiconductor Corp
Priority date: 2004-08-26
Filing date: 2004-08-26
Publication date: 2006-03-01

Abstract

An electrostatic protection device of multi-voltage source system consists of a voltage bus , the first electrostatic protection circuit set between voltage source and voltage bus , the second electrostatic protection circuit coupled between voltage bus and the second voltage source . The first electrostatic protection circuit includes an electrostatic detection unit for detecting static voltage and for generating a triggering signal , and an electrostatic discharging unit for receiving the triggering signal from said detection unit and for carrying out static discharge according to triggering signal .

Description

The electrostatic protection device that is used for the multivoltage origin system

Technical field

The present invention relates to a kind of electrostatic discharge circuit, particularly relate to a kind of electrostatic protection device that is used for the multivoltage origin system.

Background technology

Fig. 1 is a U.S. Patent number 6,075,686 disclosed static discharge modules 10.This static discharge module 10 is utilized K serial connection diode 11 and is utilized M oppositely starting voltage (the Diode turn voltage) addition respectively of serial connection diode 12, with isolated first voltage source V _DD1With second voltage source V _DD2

Yet, when first voltage source V _DD1Voltage be higher than second voltage source V _DD2Voltage the more the time, relatively the number K of diode also must increase.And because the number of the diode of serial increases, cause the resistance of discharge circuit to increase, and can't reach effect the static repid discharge.In addition when static discharge module 10, when being applied to a plurality of voltage source, the number of static discharge module 10 can increase along with the number of other voltage source and increase, thereby the increase that causes integrated circuit to build to put volume.For example when the number of other voltage source increases to 3, when just integrated circuit has 4 voltage levels, owing to must carry out electrostatic discharge (ESD) protection in twos, so the number of static discharge module 10 must increase to 6.

Therefore, how an electrostatic discharge circuit being provided, and reaching quick static discharge, can be applicable to simultaneously protect in the circuit of a plurality of voltage sources, and dwindle the area of integrated circuit, is a urgent problem in fact.

Summary of the invention

At the problems referred to above, one of purpose of the present invention is providing a kind of electrostatic protection device with bus that is used for the multivoltage origin system, and reaches quick static discharge, and effectively the protect integrated circuit assembly of (IC).

One of purpose of the present invention provides a kind of static discharge device with bus that is used for the multivoltage origin system, and reaches the circuit that protects a plurality of voltage sources simultaneously, and dwindles building of integrated circuit and put volume.

The invention provides a kind of static discharge device that is used for the multivoltage origin system, is to be used for first voltage source and at least one second voltage source are carried out electrostatic discharge (ESD) protection.This static discharge device comprises a voltage bus, one first electrostatic discharge protective circuit is to be disposed between first voltage source and the voltage bus and one second electrostatic discharge protective circuit, is coupled between this voltage bus and this second voltage source.

Wherein, this first electrostatic discharge protective circuit comprises an electrostatic detection unit, is used for detecting an electrostatic potential, and produces a triggering signal; And a static discharge unit, receive the triggering signal of electrostatic detection unit, and carry out static discharge according to this triggering signal.

And the collocation utilization by bus, first electrostatic discharge protective circuit, second electrostatic discharge protective circuit can reach the circuit that protects first voltage source and at least one second voltage source simultaneously, and dwindle the effect that building of integrated circuit put volume.

Description of drawings

Fig. 1 is known electrostatic protection module.

Fig. 2 is an electrostatic discharge protective circuit of the present invention.

Fig. 3 is used for first embodiment of the electrostatic protection device of multivoltage origin system for the present invention.

Fig. 4 is used for second embodiment of the electrostatic protection device of multivoltage origin system for the present invention.

The drawing reference numeral explanation

V _DD1First voltage source

V _DD2Second voltage source

V _DD3The tertiary voltage source

The ESD_BUS bus

21 electrostatic detection unit

211 resistance

212 electric capacity

213 nmos pass transistors

214 PMOS transistors

23 static discharge unit

11,12,231,232 diodes

233 switches

10,31,32,32 ' electrostatic discharge protective circuit

Embodiment

Describe the electrostatic discharge circuit that the present invention has bus in detail below with reference to accompanying drawing, and identical assembly will be with identical symbology.

Fig. 2 shows first embodiment of electrostatic discharge circuit of the present invention.This electrostatic discharge protective circuit 20 is used for to one first voltage source V _DD1With one second voltage source V _DD2Carry out electrostatic discharge (ESD) protection.In the present embodiment, first voltage source V _DD1Voltage be higher than second voltage source V _DD2Voltage.Electrostatic discharge protective circuit 20 comprises an electrostatic detection unit 21 and a static discharge unit 23.

In the present embodiment, electrostatic detection unit 21 is used for detecting electrostatic potential, and it comprises resistance 211 and an electric capacity 212; In another embodiment, also can comprise: a nmos pass transistor 213 and a PMOS transistor 214.Certainly, the electrostatic detection unit 21 of Fig. 2 only is a kind of embodiment, as long as the circuit that can detect electrostatic potential and produce triggering signal all can be used in the present invention.In the present embodiment, resistance 211 is connected in first voltage source V _DD1 Electric capacity 212 is connected in the resistance 211 and second voltage source V _DD2Between.The source electrode of nmos pass transistor 213 is connected in first voltage source V _DD1, its grid is connected between resistance 211 and the electric capacity 212.The source electrode of PMOS transistor 214 is connected in the drain electrode of nmos pass transistor 213, and its grid is connected in the grid of nmos pass transistor 213, and its grounded drain.The drain electrode of the source electrode of PMOS transistor 214 and nmos pass transistor 213 is defined as triggering signal, and its voltage is defined as trigger voltage.

Static discharge unit 22 has comprised a switch 233, the diode 231 of a K forward serial connection and the diode 232 of M reverse serial connection.Switch 233 can be implemented by a transistor, and controls whether conducting by triggering signal.The diode 231 of K forward serial connection is connected in the switch 233 and second voltage source V _DD2Between, use after switch 233 conductings, allow electrostatic induced current from first voltage source V _DD1Flow to second voltage source V via switch 233 and diode 231 _DD2Certainly this diode 231 can omit.M oppositely is connected in series diode 232 and is connected in first voltage source V _DD1With second voltage source V _DD2Between, as the discharge path of negative ESD.Because during positive ESD, discharge path is controlled by switch 233, the resistance of its discharge path is less relatively, so can promote discharging efficiency.

Fig. 3 shows that the present invention is used for the electrostatic protection device of multivoltage origin system.This electrostatic protection device 30 is used for to one first voltage source V _DD1With second, third voltage source V _DD2, V _DD3Carry out electrostatic discharge (ESD) protection.In this embodiment, first voltage source V _DD1Voltage far above second, third voltage source V _DD2, V _DD3Voltage, and second, third voltage source V _DD2, V _DD3Between voltage difference less.This electrostatic discharge protective circuit 30 comprises a voltage bus ESD_BUS, one first electrostatic discharge protective circuit 31 and second electrostatic discharge protective circuit 32 and the 3rd electrostatic discharge protective circuit 32 '.

First electrostatic discharge protective circuit 31 is disposed at first voltage source V _DD1And between the voltage bus ESD_BUS, use at electrostatic potential and flow into first voltage source V _DD1The time, by the control of switch 233, with electrostatic induced current from first voltage source V _DD1Bypass (bypass) is to voltage bus ESD_BUS.Because first voltage source V _DD1Voltage far above second, third voltage source V _DD2, V _DD3Voltage, so this first electrostatic discharge protective circuit 31 can be implemented by the electrostatic discharge circuit of Fig. 2.That is this first electrostatic discharge protective circuit 31 comprises an electrostatic detection unit 21 and a static discharge unit 23.Because the framework and the function of electrostatic detection unit 21 and static discharge unit 23 are same as described above, no longer repeat specification.

Second electrostatic discharge protective circuit 32 is disposed at the voltage bus ESD_BUS and second voltage source V _DD2Between, and the 3rd electrostatic discharge protective circuit 32 ' is disposed at voltage bus ESD_BUS and tertiary voltage source V _DD3Between.Because second, third voltage source V _DD2, V _DD3Between voltage difference less, therefore the electrostatic discharge protective circuit enforcement that second electrostatic discharge protective circuit 32 and the 3rd electrostatic discharge protective circuit 32 ' can be known, for example electrostatic discharge protective circuit of Fig. 1.So the number of diodes that second electrostatic discharge protective circuit 32 and the 3rd electrostatic discharge protective circuit 32 ' comprise does not need can effectively reduce the resistance of electrostatic discharging path too much, improve the speed of static discharge.And the number of diodes that second electrostatic discharge protective circuit 32 and the 3rd electrostatic discharge protective circuit 32 ' comprise is by second, third voltage source V _DD2, V _DD3Between voltage difference decide.Certainly, if second, third voltage source V _DD2, V _DD3Between voltage difference also greater than a magnitude of voltage, then the electrostatic discharge circuit that second electrostatic discharge protective circuit 32 and the 3rd electrostatic discharge protective circuit 32 ' can also Fig. 2 is implemented.

This electrostatic protection device 30 working voltage bus ESD_BUS come simultaneously to first, second, with tertiary voltage source V _DD1, V _DD2, V _DD3Carry out electrostatic discharge (ESD) protection, comparatively simple on circuit design.Therefore in first voltage source V _DD1With second voltage source V _DD2Between when having positive electrostatic potential to produce, electrostatic detection unit 21 can produce triggering signals, makes transistor 233 conductings in the static discharge unit 23, allows electrostatic induced current from first voltage source V _DD1Switch to second voltage source V via electrostatic protection module 32 _DD2And in first voltage source V _DD1With second voltage source V _DD2Between when having negative electrostatic potential to produce, electrostatic induced current is from second voltage source V _DD2Through electrostatic protection module 32 be connected in series diode 232 and switch to first voltage source V _DD1And when second with tertiary voltage source V _DD2, V _DD3Between when having positive electrostatic potential to produce, this electrostatic induced current can be from second voltage source V _DD2 Serial connection diode 322 via electrostatic protection module 32 switches to voltage bus ESD_BUS, switches to tertiary voltage source V by voltage bus ESD_BUS via the serial connection diode 321 of electrostatic protection module 32 ' again _DD3And when second with tertiary voltage source V _DD2, V _DD3Between when having negative electrostatic potential to produce, this electrostatic induced current can be from tertiary voltage source V _DD3 Serial connection diode 322 via electrostatic protection module 32 ' switches to voltage bus ESD_BUS, switches to second voltage source V by voltage bus ESD_BUS via the serial connection diode 321 of electrostatic protection module 32 again _DD2

Fig. 4 shows that the present invention is used for another embodiment of the electrostatic protection device of multivoltage origin system.This electrostatic protection device 40 is used for to one first voltage source V _DD1With second, third voltage source V _DD2, V _DD3Carry out electrostatic discharge (ESD) protection.In this embodiment, first voltage source V _DD1Voltage be lower than second, third voltage source V _DD2, V _DD3Voltage, and second, third voltage source V _DD2, V _DD3Between voltage difference less.This electrostatic protection device 40 is identical with the electrostatic protection device 30 of Fig. 3, all comprises a voltage bus ESD_BUS, first electrostatic discharge protective circuit 31 and second electrostatic discharge protective circuit 32 and the 3rd electrostatic discharge protective circuit 32 ', and its difference is first voltage source V _DD1Voltage far below second, third voltage source V _DD2, V _DD3Voltage.

Therefore in second voltage source V _DD2With first voltage source V _DD1Between when having positive electrostatic potential to produce, electrostatic detection unit 21 can produce triggering signals, makes transistor 233 conductings in the static discharge unit 23, allows electrostatic induced current switch to first voltage source V via electrostatic protection module 32 and transistor 233 _DD1And in second voltage source V _DD2With first voltage source V _DD1Between when having negative electrostatic potential to produce, electrostatic induced current is from first voltage source V _DD1Switch to second voltage source V through serial connection diode 232 with electrostatic protection module 32 _DD2

Though more than with embodiment the present invention is described, therefore do not limit scope of the present invention, only otherwise break away from main idea of the present invention, those skilled in the art can carry out various distortion or change.

Claims

1. electrostatic protection device that is used for the multivoltage origin system, this multi-power system comprises one first voltage source and one second voltage source, this electrostatic protection device comprises:

One voltage bus;

One first electrostatic discharge protective circuit is disposed between this first voltage source and this voltage bus; And

One second electrostatic discharge protective circuit is coupled between this voltage bus and this second voltage source.

2. the static discharge device that is used for the multivoltage origin system as claimed in claim 1, wherein this first electrostatic discharge protective circuit comprises:

One electrostatic detection unit is used for detecting an electrostatic potential, and produces a triggering signal; And

One static discharge unit is coupled to this electrostatic detection unit, according to this triggering signal in order to carry out this static discharge.

3. the electrostatic discharge circuit that is used for the multivoltage origin system as claimed in claim 2; wherein this static discharge unit also comprises a negative esd protection unit; use when first voltage source and voltage bus have negative electrostatic potential to produce, electrostatic induced current is switched to first voltage source by voltage bus.

4. the electrostatic discharge circuit that is used for the multivoltage origin system as claimed in claim 2, wherein this electrostatic detection unit comprises:

One resistance; And

One electric capacity is connected in this resistance, forms an end points, and this end points is exported this triggering signal.

5. the electrostatic discharge circuit that is used for the multivoltage origin system as claimed in claim 2, wherein this electrostatic detection unit comprises:

One resistance;

One electric capacity is connected in this resistance;

One nmos pass transistor, its grid are connected between this resistance and this electric capacity; And

One PMOS transistor, its grid is connected in the grid of aforementioned nmos pass transistor, and its source electrode is connected in the drain electrode of this nmos pass transistor, forms an end points, and this end points is exported this triggering signal.

6. the electrostatic discharge circuit that is used for the multivoltage origin system as claimed in claim 2, wherein aforementioned static discharge unit is a switch.

7. the electrostatic discharge circuit that is used for the multivoltage origin system as claimed in claim 1, wherein this second electrostatic discharge protective circuit diode that is a serial.

8. electrostatic protection device that is used for the multivoltage origin system, this multi-power system comprises one first voltage source, one second voltage source and a tertiary voltage source, this electrostatic protection device comprises:

One voltage bus;

One first electrostatic discharge protective circuit is disposed between this first voltage source and this voltage bus;

One second electrostatic discharge protective circuit is coupled between this voltage bus and this second voltage source; And

One the 3rd electrostatic discharge protective circuit is coupled between this voltage bus and this tertiary voltage source.

9. the static discharge device that is used for the multivoltage origin system as claimed in claim 8, wherein aforementioned first electrostatic discharge protective circuit comprises:

10. the electrostatic discharge circuit that is used for the multivoltage origin system as claimed in claim 9, wherein this electrostatic detection unit comprises:

One resistance; And