CN100581021C

CN100581021C - Static protection circuit device

Info

Publication number: CN100581021C
Application number: CN200710127385A
Authority: CN
Inventors: 林孟勇; 吴柏樟; 欧威扬; 黄启模
Original assignee: ILI Techonology Corp
Current assignee: ILI Techonology Corp
Priority date: 2007-07-02
Filing date: 2007-07-02
Publication date: 2010-01-13
Anticipated expiration: 2027-07-02
Also published as: CN101340085A

Abstract

The invention discloses an electrostatic protection circuit device, which comprises a first switch element, a second switch element and a third switch element, wherein the first end of the first switch element is coupled with a first signal; a first control element coupled to the first signal for generating a first control signal according to the first signal; a second switch element having a first end coupled to a second signal, a second end coupled to a second end of the first switch element, and a control end coupled to the first control element; the second control element is coupled to the second signal and a control end of the first switch element and used for generating a second control signal according to the second signal; the first control signal is coupled to the control end of the second switch, and the second control signal is coupled to the control end of the first switch.

Description

Electrostatic protection circuit apparatus

Technical field

The present invention relates to a kind of electrostatic protection circuit apparatus, particularly a kind of transistor unit that utilizes comes device to electrostatic protection between two different supply voltages.

Background technology

Please refer to Fig. 1, shown in Figure 1 is the schematic diagram of an existing electrostatic discharge protective circuit 10.Electrostatic discharge protective circuit 10 includes one first group of diode in series 11 and one second group of diode in series 12.First group of diode in series 11 is coupled to one first a power end N1 and a second source end N2, and wherein, the first power end N1 is used for receiving one first voltage source V dd1 and second source end N2 is used for receiving one second voltage source V dd2.Similarly, second group of diode in series 12 also is coupled to the first power end N1 and second source end N2, the difference of the two is with respect to the first voltage source V dd1 and the second voltage source V dd2, with Vdd2＞Vdd1 when the normal running is example, first group of diode in series 11 is forward, and second group of diode in series 12 is reverse.When the wherein end of the first power end N1 and second source end N2 has the generation of electrostatic pulse signal, with the first power end N1 is example, and then second group of diode in series 12 will conducting and promoted the first power end N1 and second source end N2 synchronously according to the amplitude of electrostatic pulse signal and divide other voltage.On the contrary, when second source end N2 has the electrostatic pulse signal when producing, then first group of diode in series 11 will conducting and promoted the first power end N1 and second source end N2 synchronously according to the amplitude of electrostatic pulse signal and divide other voltage.Thus, the first voltage source V dd1 and the pairing Circuits System of the second voltage source V dd2 cause the damage of element in the Circuits System with regard to not producing huge voltage difference.Yet; existing electrostatic discharge protective circuit 10 has at least two problems; first; when the voltage difference between the desired first voltage source V dd1 of system and the second voltage source V dd2 is too big; then the number of diodes of first group of diode in series 11 and second group of diode in series 12 just must suitably increase, but will cause the reaction of existing electrostatic discharge protective circuit 10 to cross when number of diodes is too many can't to promote the first power end N1 in time synchronously slowly and second source end N2 divides other voltage.Second, on real the work, the first voltage source V dd1 and the second voltage source V dd2 are two voltage sources independently, therefore open or close Shi Douhui synchronously at first group of diode in series 11 or second group of huge forward conducting electric current of diode in series 12 generations as the first voltage source V dd1 and the second voltage source V dd2, this causes damage to the element in the Circuits System easy as can once conducting electric current forward.

Summary of the invention

Therefore, a purpose of the present invention is to provide a kind of transistor unit that utilizes to come device to electrostatic protection between two different supply voltages.

One embodiment of the invention provide a kind of circuit arrangement, include one first switch element, one first control element, a second switch element and one second control element.This first switch element has one first end and is coupled to one first signal; This first control element is coupled to a control end of this first signal and this second switch element, is used for according to this first signal to produce one first control signal; This second switch element has one first end and is coupled to a secondary signal, and one second end is coupled to one second end of this first switch element; And this second control element, be coupled to a control end of this secondary signal and this first switch element, be used for according to this secondary signal to produce one second control signal; Wherein, this first control signal is coupled to this control end of this second switch, and this second control signal is coupled to this control end of this first switch.

Description of drawings

Shown in Figure 1 is the schematic diagram of an existing electrostatic discharge protective circuit.

Shown in Figure 2 is the sincere figure of an embodiment of foundation a kind of electrostatic protection circuit apparatus of the present invention

Shown in Figure 3 is the schematic diagram that electrostatic protection circuit apparatus shown in Figure 2 operates in this direct current supplying mode.

Shown in Figure 4 is the schematic diagram that electrostatic protection circuit apparatus shown in Figure 2 operates in this electrostatic protection pattern.

The reference numeral explanation

10	Electrostatic discharge protective circuit
10	Electrostatic discharge protective circuit	11、12	Series diode
200	Electrostatic protection circuit apparatus	11、12	Series diode
200	Electrostatic protection circuit apparatus	201、203	Switch element
202、204	Control element	201、203	Switch element

Embodiment

In the middle of specification and follow-up claim, used some vocabulary to censure specific element.The person with usual knowledge in their respective areas should understand, and hardware manufacturer may be called same element with different nouns.This specification and follow-up claim are not used as distinguishing the mode of element with the difference of title, but the criterion that is used as distinguishing with the difference of element on function.Be an open term mentioned " comprising " in the middle of specification and the follow-up request item in the whole text, so should be construed to " comprise but be not limited to ".In addition, " couple " speech and comprise any indirect means that are electrically connected that directly reach at this.Therefore, be coupled to one second device, then represent this first device can directly be electrically connected in this second device, or be electrically connected to this second device indirectly through other device or connection means if describe one first device in the literary composition.

Please refer to Fig. 2; shown in Figure 2 is the sincere figure of an embodiment of foundation a kind of electrostatic protection circuit apparatus 200 of the present invention, and electrostatic protection circuit apparatus 200 includes one first switch element 201, one first control element 202, a second switch element 203 and one second control element 204.Embodiments of the invention electrostatic protection circuit apparatus 200 is used to provide one first power voltage terminal N _VDD1With a second source voltage end N _VDD2Between an electrostatic protection mechanism, wherein, the first power voltage terminal N _VDD1With second source voltage end N _VDD2Be used for accepting one first supply voltage V respectively _DD1With a second source voltage end V _DD2, and the first supply voltage V _DD1Be not equal to second source voltage end V _DD2Therefore, operate in normal mode following time, one first end of first switch element 201 (that is the first power voltage terminal N when electrostatic protection circuit apparatus 200 of the present invention _VDD1) be used for receiving the first supply voltage V _DD1 First control element 202 is coupled to the first power voltage terminal N _VDD1Control end N with second switch element 203 _C2, be used for according to the first supply voltage V _DD1To produce one first control signal V _C1 Second switch element 202 has one first end (that is the first power voltage terminal N _VDD2) be used for receiving second source voltage end V _DD2, one second end N _BulkBe coupled to one second end (that is N of first switch element 201 _Bulk); And second control element 204 be coupled to second source voltage end V _DD2Control end N with first switch element 201 _C1, be used for according to second source voltage end V _DD2To produce one second control signal V _C2Wherein, the first control signal V _C1Be coupled to the control end N of first control element 202 _C2, and the second control signal V _C2Be coupled to the control end N of second control element 204 _C1On the other hand, in order more clearly to describe spiritual place of the present invention, first switch element 201 in the present embodiment electrostatic protection circuit apparatus 200 is one the one P type field-effect transistor M _P1, and the control end N of first switch element 201 _C1It is a grid of a P type field-effect transistor; Second switch element 203 is one the 2nd P type field-effect transistor M _P2, and the control end N of second switch element 203 _C2Be the 2nd P type field-effect transistor M _P2A grid.Note that being familiar with this operator should understand, via embodiment of the invention electrostatic protection circuit apparatus 200 is suitably adjusted, first switch element 201 also can be done by two N type field-effect transistors respectively in fact with second switch element 203.On the other hand, first control element 202 is one first filters, and it is by a capacitor C ₁With a resistance R ₁Form, be used for to the first supply voltage V _DD1Carry out filtering and produce the first control signal V _C1And second control element 204 are one second filters, it is by a capacitor C ₂With a resistance R ₂Form, be used for to second source voltage V _DD2Carry out filtering to produce the second control signal V _C2Note that this first filter and this second filter all are low-pass filter circuits, and a P type field-effect transistor M _P1A substrate (Substrate) be coupled to a P type field-effect transistor M _P1The second end N _Bulk, the 2nd P type field-effect transistor M _P2A substrate be coupled to the 2nd P type field-effect transistor M _P2Second end (that is N _Bulk), while the one P type field-effect transistor M _P1This substrate and the 2nd P type field-effect transistor M _P2This substrate be suspension joint (floating) state, as shown in Figure 2.

According to embodiments of the invention electrostatic protection circuit apparatus 200, its operation can be divided into a direct current supplying mode and an electrostatic protection pattern.Please refer to Fig. 3, shown in Figure 3 is the schematic diagram that the electrostatic protection circuit apparatus 200 of the embodiment of the invention operates in this direct current supplying mode.For clearer description spiritual place of the present invention, the first supply voltage V _DD1Setting is higher than second source voltage V _DD2, V for example _DD1=10V, V _DD2=5V.Therefore, work as V _DD1During=10V, the 2nd P type field-effect transistor M _P2Control end N _C2Also can make and charge to 10V (that is the first control signal V _C1).On the other hand, work as V _DD2During=5V, a P type field-effect transistor M _P1Control end N _C1Also can make and charge to 5V (that is the second control signal V _C2), therefore, a P type field-effect transistor M _P1Can be switched on and produce a conducting electric current I _{Turn_on1}To a P type field-effect transistor M _P1The second end N _BulkCharge, until the second end N _BulkVoltage reach till the 10V.Thus, the 2nd P type field-effect transistor M _P2Can be closed.Can learn thus, when the electrostatic protection circuit apparatus 200 of the embodiment of the invention operates in this direct current supplying mode, the first supply voltage V _DD1Can conducting to second source voltage V _DD2Otherwise, as the first supply voltage V _DD1Setting is lower than second source voltage V _DD2, V for example _DD1=5V, V _DD2During=10V, the 2nd P type field-effect transistor M _P2Conducting and a P type field-effect transistor M _P1Close.So under this direct current supplying mode, the first supply voltage V _DD1And second source voltage V _DD2Being able to normally provides voltage source to its corresponding circuit.

Please refer to Fig. 4, shown in Figure 4 is the schematic diagram that the electrostatic protection circuit apparatus 200 of the embodiment of the invention operates in this electrostatic protection pattern.For clearer description spiritual place of the present invention, under initial state, electrostatic protection circuit apparatus 200 is operating in this direct current supplying mode, for example the first supply voltage V _DD1Be 10V and second source voltage V _DD1Be 5V.As the first power voltage terminal N _VDD1The first supply voltage V _DD1When having a static (ESD) pulse, this electrostatic pulse will be at once with the first supply voltage V _DD1Promote paranormal 10V far away, for example when this electrostatic pulse is the transient pulse of a 10V, the first power voltage terminal N _VDD1The first supply voltage V _DD1Will be promoted to 20V, as shown in Figure 4.A because P type field-effect transistor M under initial state _P1Be the state of conducting, so a P type field-effect transistor M _P1Can produce a conducting electric current I _{Turn_on2}Flow to a P type field-effect transistor M _P1The second end N _BulkNote that owing to when this direct current supplying mode the second end N _BulkBe charged to 10V, so the conducting electric current I _{Turn_on2}Will open the 2nd P type field-effect transistor M moment _P2Note that at one time this first filter can make the 2nd P type field-effect transistor M _P2Control end N _C2Temporarily be in 10V (the first control signal V _C1).Therefore, the 2nd P type field-effect transistor M _P2Will be switched on and with this conducting electric current I _{Turn_on2}Flow to second source voltage end N _VDD2, and this electrostatic pulse will be switched on to second source voltage end N _VDD2Second source voltage V _DD2So once, second source voltage end N _VDD2Second source voltage V _DD2Will be promoted to 20V from 5V originally.Note that working as this electrostatic pulse is switched on to second source voltage end N _VDD2The time, this second filter can make the P type field-effect transistor M that wins _P1Control end N _C1Temporarily maintain 5V (the second control signal V _C2) and make the 2nd P type field-effect transistor M _P2Continued conducting, until till this electrostatic pulse end.Can learn thus, when the electrostatic protection circuit apparatus 200 of the embodiment of the invention operates in this electrostatic protection pattern, the first supply voltage V _DD1And second source voltage V _DD2Can promote corresponding voltage levels synchronously along with the pulse amplitude of this electrostatic pulse, therefore, the first supply voltage V _DD1And second source voltage V _DD2Pairing circuit just can be avoided the interference of static and normally be operated.Otherwise, as second source voltage end N _VDD2Second source voltage V _DD2When having a static (ESD) pulse, have the knack of this skill person must understand the embodiment of the invention after reading above disclosed implementation and operation operating process, therefore do not give unnecessary details in addition.

On the other hand, because when embodiments of the invention electrostatic protection circuit apparatus 200 operated in this direct current supplying mode, wherein, a P type field-effect transistor must be closing state, therefore as the first supply voltage V _DD1And second source voltage V _DD2When being not close synchronously, the first supply voltage V _DD1And second source voltage V _DD2Between the huge forward current that produces just can't be at the first power voltage terminal N _VDD1With second source voltage end N _VDD2Between conducting.Thus, the first supply voltage V _DD1And second source voltage V _DD2Pairing circuit can not damaged by this huge forward current.Otherwise, when embodiments of the invention electrostatic protection circuit apparatus 200 when closing, a P type field-effect transistor M _P1With the 2nd P type field-effect transistor M _P2Be closing state, and the second end N of its common suspension joint _BulkAlso be in the state that is not recharged, that is the second end N _BulkVoltage be 0V.Therefore, as the first supply voltage V _DD1And second source voltage V _DD2Not when being unlocked synchronously, the first supply voltage V _DD1And second source voltage V _DD2Between the huge forward current that produces just essential earlier to the second end N _BulkCharge, thus, this huge forward current just can not flow to moment the other end, therefore the first voltage V _DD1And second source voltage V _DD2Pairing circuit can not damaged by this huge forward current.

The above only is preferred embodiment of the present invention, and all equalizations of being done according to the present patent application claim change and modify, and all should belong to covering scope of the present invention.

Claims

1. electrostatic protection circuit apparatus includes:

One first switch element has one first end and is coupled to one first signal;

One first control element is coupled to this first signal, is used for according to this first signal to produce one first control signal;

One second switch element has one first end and is coupled to a secondary signal, and one second end is coupled to one second end of this first switch element, and a control end is coupled to this first control element; And

One second control element is coupled to a control end of this secondary signal and first switch element, is used for according to this secondary signal to produce one second control signal;

Wherein, this first control signal is coupled to this control end of this second switch, and this second control signal is coupled to this control end of this first switch.

2. electrostatic protection circuit apparatus as claimed in claim 1, wherein, this first switch element is a first transistor, and this control end of this first switch element is a grid of this first transistor; This second switch element is a transistor seconds, and this control end of this second switch element is a grid of this transistor seconds; This first control element is one first filter, is used for that this first signal is carried out filtering and produces this first control signal; And this second control element is one second filter, is used for this secondary signal is carried out filtering to produce this second control signal.

3. electrostatic protection circuit apparatus as claimed in claim 2, wherein, a substrate of this first transistor is coupled to this second end of this first transistor, and a substrate of this transistor seconds is coupled to this second end of this transistor seconds.

4. electrostatic protection circuit apparatus as claimed in claim 3, wherein, this substrate of this first transistor and this substrate of this transistor seconds are floating.

5. electrostatic protection circuit apparatus as claimed in claim 2, wherein, this first transistor and this transistor seconds all are P type field-effect transistors.

6. electrostatic protection circuit apparatus as claimed in claim 2, wherein, this first transistor and this transistor seconds all are N type field-effect transistors.

7. electrostatic protection circuit apparatus as claimed in claim 2, wherein, this first filter and this second filter all are low pass filters.

8. electrostatic protection circuit apparatus as claimed in claim 1, wherein, the power supply signal that this first, second signal is different voltage levels.