JPH0529895A - Hysteresis circuit - Google Patents

Hysteresis circuit

Info

Publication number
JPH0529895A
JPH0529895A JP16126791A JP16126791A JPH0529895A JP H0529895 A JPH0529895 A JP H0529895A JP 16126791 A JP16126791 A JP 16126791A JP 16126791 A JP16126791 A JP 16126791A JP H0529895 A JPH0529895 A JP H0529895A
Authority
JP
Japan
Prior art keywords
potential
voltage
inverter
node
vcc
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
Application number
JP16126791A
Other languages
Japanese (ja)
Inventor
Sadahisa Isobe
禎久 磯部
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
NEC IC Microcomputer Systems Co Ltd
Original Assignee
NEC IC Microcomputer Systems Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by NEC IC Microcomputer Systems Co Ltd filed Critical NEC IC Microcomputer Systems Co Ltd
Priority to JP16126791A priority Critical patent/JPH0529895A/en
Publication of JPH0529895A publication Critical patent/JPH0529895A/en
Pending legal-status Critical Current

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Abstract

PURPOSE:To realize the hysteresis circuit in which number of circuit components is reduced and the design process of setting an upper limit level and a lower limit level of a hysteresis is facilitated. CONSTITUTION:When an input voltage Vi changes from a ground potential Vg to a power supply voltage Vcc, a potential VA at a node A rises while keeping a potential difference between the Vi and a threshold voltage VT1 of an NMOS1 after the voltage Vi is higher than the VA by the VT1. When the potential VA is larger than a threshold voltage VR of an inverter 3, the inverter 3 is inverted and an output voltage VO goes to Vg. When the Vi is equal to Vcc, the potential VA reaches a potential lower than the Vcc by the VT1, the NMOS5 is conductive and the Vo is equal to the Vg. When the Vi changes from the Vcc to the Vg, the potential VA is decreased while keeping a potential difference between the Vi and a VT2 after the Vi is lower than the potential VA by a threshold level VT2 of the NMOS2. When the potential VA is lower than the VR, the inverter 3 is inverted and the Vcc is outputted as the VO.

Description

【発明の詳細な説明】Detailed Description of the Invention

【0001】[0001]

【産業上の利用分野】本発明はヒステリシス回路に関
し、特に半導体集積回路用として用いられるヒステリシ
ス回路に関する。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hysteresis circuit, and more particularly to a hysteresis circuit used for semiconductor integrated circuits.

【0002】[0002]

【従来の技術】従来の半導体集積回路用のヒステリシス
回路は、図3に示されるように、入力端子53および出
力端子54に対応して、PチャネルMOSFET6、8
および10と、NチャネルMOSFET7、9および1
1とを備えて構成される。
2. Description of the Related Art A conventional hysteresis circuit for a semiconductor integrated circuit has P channel MOSFETs 6 and 8 corresponding to an input terminal 53 and an output terminal 54, as shown in FIG.
And 10 and N-channel MOSFETs 7, 9 and 1
1 and 1.

【0003】図3において、入力電圧Vi が接地電位V
g の時には、PチャネルMOSFET6および8と、N
チャネルMOSFET11は導通状態となっており、出
力端子54の出力電圧Vo は電源電圧Vccとなってい
る。そして、入力電圧Vi が接地電位Vg からVccに変
化する時のしきい値電圧VIHは、PチャネルMOSFE
T6および8と、NチャネルMOSFET7とによって
規定される。
In FIG. 3, the input voltage V i is the ground potential V
When g , P-channel MOSFETs 6 and 8 and N
Channel MOSFET11 is rendered conductive, the output voltage V o of the output terminal 54 has a power supply voltage V cc. The threshold voltage V IH when the input voltage V i changes from the ground potential V g to V cc is P-channel MOSFE.
Defined by T6 and 8 and N-channel MOSFET 7.

【0004】また、入力電圧Vi が電位Vccである場合
には、PチャネルMOSFET10と、NチャネルMO
SFET7および9が導通状態となって、出力端子54
の出力電圧Vo は接地電位Vg となり、入力電圧Vi
電位Vccから接地電位Vgに変化する時のしきい値電圧
ILは、PチャネルMOSFET6と、NチャネルMO
SFET7および9とにより規定される。
When the input voltage V i is the potential V cc , the P channel MOSFET 10 and the N channel MO are connected.
The SFETs 7 and 9 become conductive, and the output terminal 54
Output voltage V o becomes the ground potential V g , and the threshold voltage V IL when the input voltage V i changes from the potential V cc to the ground potential V g is the P channel MOSFET 6 and the N channel MO.
Defined by SFETs 7 and 9.

【0005】上記の説明により明らかなように、前記二
つのしきい値電圧については、VIH>VILであり、図3
に示される回路は、この二つのしきい値電圧VIHとVIL
の差電圧をヒステリシス幅とする、ヒステリシス回路と
して構成されている。
As is clear from the above description, for the two threshold voltages, V IH > V IL , and FIG.
The circuit shown in FIG. 2 has two threshold voltages V IH and V IL.
It is configured as a hysteresis circuit in which the difference voltage of is the hysteresis width.

【0006】[0006]

【発明が解決しようとする課題】上述した従来のヒステ
リシス回路においては、出力端子に正帰還をかけること
により、VIHおよびVILの二つのしきい値電圧の設定が
行われているために、正帰還をかけるための回路が必要
であり、通常のゲート回路に比較して、回路素子数が多
くなるという欠点がある。また、二つのしきい値電圧V
IHおよびVILを設定する際に、それぞれ三つのMOSF
ETについて考慮する必要があり、設計が複雑になると
いう欠点がある。
In the above-mentioned conventional hysteresis circuit, since two threshold voltages V IH and V IL are set by applying positive feedback to the output terminal, A circuit for applying positive feedback is required, and there is a drawback in that the number of circuit elements is large as compared with a normal gate circuit. In addition, two threshold voltages V
When setting IH and V IL , each has three MOSF
ET must be taken into consideration, and there is a drawback in that the design becomes complicated.

【0007】[0007]

【課題を解決するための手段】本発明のヒステリシス回
路は、ドレインおよびゲートが共に入力端子に接続さ
れ、ソースが所定の節点に接続される第1のNチャネル
MOSFETと、ソースが前記入力端子に接続され、ド
レインおよびゲートが共に前記節点に接続される第2の
NチャネルMOSFETと、入力端が前記節点に接続さ
れ、出力端が出力端子に接続されるインバータと、を備
えて構成される。
In the hysteresis circuit of the present invention, a drain and a gate are both connected to an input terminal and a source is connected to a predetermined node, and a source is connected to the input terminal. A second N-channel MOSFET that is connected and has its drain and gate both connected to the node, and an inverter having an input terminal connected to the node and an output terminal connected to an output terminal.

【0008】なお、前記インバータは、ゲートが前記入
力端に接続され、ドレインが所定の直流電源に接続され
て、ソースが前記出力端に接続される第1のPチャネル
MOSFETと、ゲートが前記入力端に接続され、ソー
スが前記出力端に接続されて、ドレインが前記出力端に
接続される第3のNチャネルMOSトランジスタにより
形成してもよい。
The inverter has a first P-channel MOSFET having a gate connected to the input terminal, a drain connected to a predetermined DC power source, and a source connected to the output terminal, and a gate connected to the input terminal. It may be formed by a third N-channel MOS transistor connected to the end, the source connected to the output end, and the drain connected to the output end.

【0009】[0009]

【実施例】次に、本発明について図面を参照して説明す
る。
DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings.

【0010】図1は本発明の一実施例を示すブロック図
である。図1に示されるように、本実施例は、入力端子
51および出力端子52に対応して、NチャネルMOS
FET1、2および5と、PチャネルMOSFET4
と、PチャネルMOSFET4およびNチャネルMOS
FET5を含むインバータ3と、を備えて構成される。
また、図2(a)および(b)に示されるのは、本実施
例における各信号を示すタイミング図である。
FIG. 1 is a block diagram showing an embodiment of the present invention. As shown in FIG. 1, this embodiment corresponds to an input terminal 51 and an output terminal 52 and corresponds to an N channel MOS.
FETs 1, 2 and 5 and P-channel MOSFET 4
And P-channel MOSFET 4 and N-channel MOS
And an inverter 3 including a FET 5.
Further, FIGS. 2A and 2B are timing charts showing respective signals in this embodiment.

【0011】図1において、NチャネルMOSFET1
および2は、共にドレインとゲートが接続されてダイオ
ード接続されており、NチャネルMOSFET1は、節
点Aの側から入力端子51に対しては電流を流すことが
なく、また、NチャネルMOSFET2は、入力端子5
1の側から節点Aに対しては電流を流すことがない。
In FIG. 1, an N-channel MOSFET 1
Both drains and gates are diode-connected by connecting their drains and gates, the N-channel MOSFET 1 does not flow a current from the node A side to the input terminal 51, and the N-channel MOSFET 2 has an input. Terminal 5
No current flows from the 1 side to the node A.

【0012】図2(a)および(b)に示されているよ
うに、入力端子51における入力電圧Vi が接地電位V
g である場合には、節点Aにおける電位VA は、Nチャ
ネルMOSFET2のしきい値電圧VT2だけ接地電位V
g より高い電位になっており、PチャネルMOSFET
4は導通状態となり、出力端子52の出力電圧Vo は電
源電圧Vccとなっている。入力電圧Vi が接地電位Vg
から電位Vccに変化すると、節点Aの電位VA は、入力
電圧Vi がNチャネルMOSFET1のしきい値電圧V
T1だけ節点Aの電位VA よりも高くなる時点から、入力
電圧Vi と、NチャネルMOSFET1のしきい値電圧
T1分の電位差を保持しながら上昇してゆく。節点Aの
電位VA が、インバータ3のしきい値電圧VR よりも大
きくなると、インバータ3は反転し、出力端子52の出
力電圧Vo は接地電位Vg となる。また、入力電圧Vi
がVccである場合には、節点Aの電位VA は、Nチャネ
MOSFET1のしきい値電圧VT1だけ電源電圧Vcc
りも低い電位になっており、NチャネルMOSFET5
が導通状態となり、出力端子52の出力電圧Vo は接地
電位Vg となっている。そして、入力電圧Vi がVcc
ら接地電位Vg に変化すると、節点Aの電位VA は、入
力電圧Vi がNチャネルMOSFET2のしきい値電圧
T2だけ節点Aの電位VA よりも低くなる時点から、入
力電圧Vi と、NチャネルMOSFET2のしきい値電
圧VI2分の電位差を保持しながら下降してゆく。節点A
の電位VA がインバータ3のしきい値電圧VR より低く
なると、インバータ3は反転し、出力端子52の出力電
圧Vo として、電源電圧Vccが出力される。
As shown in FIGS. 2A and 2B, the input voltage V i at the input terminal 51 is the ground potential V i.
When g , the potential V A at the node A is equal to the ground potential V T by the threshold voltage V T2 of the N-channel MOSFET 2.
The potential is higher than g , and P-channel MOSFET
4 becomes conductive, the output voltage V o of the output terminal 52 has a power supply voltage V cc. The input voltage V i is the ground potential V g
If changes to the potential V cc from the potential V A of the node A, the input voltage V i is N-channel MOSFET1 threshold voltage V
From the time point when the voltage becomes higher than the potential V A of the node A by T1 , the voltage rises while maintaining the potential difference between the input voltage V i and the threshold voltage V T1 of the N-channel MOSFET 1. When the potential V A of the node A becomes larger than the threshold voltage V R of the inverter 3, the inverter 3 is inverted and the output voltage V o of the output terminal 52 becomes the ground potential V g . In addition, the input voltage V i
Is V cc , the potential V A of the node A is lower than the power supply voltage V cc by the threshold voltage V T1 of the N-channel MOSFET 1, and the N-channel MOSFET 5
Becomes conductive, and the output voltage V o of the output terminal 52 becomes the ground potential V g . Then, when the input voltage V i changes from V cc to the ground potential V g , the potential V A of the node A is lower than the potential V A of the node A by the threshold voltage V T2 of the input voltage V i of the N-channel MOSFET 2. From the time when the voltage becomes low, the input voltage V i and the threshold voltage V I2 of the N-channel MOSFET 2 decrease while maintaining the potential difference. Node A
When the potential V A is lower than the threshold voltage V R of the inverter 3, inverter 3 inverts, as the output voltage V o of the output terminal 52, the power supply voltage V cc is outputted.

【0013】従って、図1に示される本実施例において
は、VIH=VR +VT1であり、また、VIL=VR −VT2
である。従って、本実施例は、ヒステリシス幅がVIH
IL=VT1+VT2となるようなヒステリシス回路として
構成される。
Therefore, in this embodiment shown in FIG. 1, V IH = V R + V T1 and V IL = V R -V T2.
Is. Therefore, in this embodiment, the hysteresis width is V IH −.
It is configured as a hysteresis circuit such that V IL = V T1 + V T2 .

【0014】[0014]

【発明の効果】以上説明したように、本発明は、ダイオ
ード接続のMOSFETを用いてヒステリシス幅の上限
電位レベルVIHならびに下限電位レベルVILを設定する
ことにより、回路素子数を低減することができるという
効果があるとともに、また、前記上限電位レベルVIH
らびに下限電位レベルVILの設定時においては、それぞ
れインバータのしきい値電圧VR に対する、前記ダイオ
ード接続のMOSFETのしきい値電圧について考慮す
ればよく、設計プロセスが簡易化されるという効果があ
る。
As described above, the present invention can reduce the number of circuit elements by setting the upper limit potential level V IH and the lower limit potential level V IL of the hysteresis width by using the diode-connected MOSFET. together there is an effect that it also in the setting time of the upper limit voltage level V IH and lower potential level V IL is for the threshold voltage V R of the inverter, respectively, consider the threshold voltage of the MOSFET of said diode-connected This has the effect of simplifying the design process.

【図面の簡単な説明】[Brief description of drawings]

【図1】本発明の一実施例を示す回路図である。FIG. 1 is a circuit diagram showing an embodiment of the present invention.

【図2】本実施例における動作例を示すタイミング図で
ある。
FIG. 2 is a timing chart showing an operation example in the present embodiment.

【図3】従来例を示す回路図である。FIG. 3 is a circuit diagram showing a conventional example.

【符号の説明】[Explanation of symbols]

1、2、5、7、9、11 NチャネルMOSFET 3 インバータ 4、6、8、10 PチャネルMOSFFT 1, 2, 5, 7, 9, 11 N-channel MOSFET 3 inverter 4, 6, 8, 10 P-channel MOSFFT

Claims (2)

【特許請求の範囲】[Claims] 【請求項1】 ドレインおよびゲートが共に入力端子に
接続され、ソースが所定の節点に接続される第1のNチ
ャネルMOSFETと、 ソースが前記入力端子に接続され、ドレインおよびゲー
トが共に前記節点に接続される第2のNチャネルMOS
FETと、 入力端が前記節点に接続され、出力端が出力端子に接続
されるインバータと、 を備えることを特徴とするヒステリシス回路。
1. A first N-channel MOSFET having a drain and a gate both connected to an input terminal and a source connected to a predetermined node; and a source connected to the input terminal and a drain and a gate both connected to the node. Second N-channel MOS connected
A hysteresis circuit, comprising: a FET; and an inverter having an input end connected to the node and an output end connected to an output terminal.
【請求項2】 前記インバータが、ゲートが前記入力端
に接続され、ドレインが所定の直流電源に接続されて、
ソースが前記出力端に接続される第1のPチャネルMO
SFETと、ゲートが前記入力端に接続され、ソースが
前記出力端に接続されて、ドレインが前記出力端に接続
される第3のNチャネルMOSトランジスタにより形成
される請求項1記載のヒステリシス回路。
2. The inverter has a gate connected to the input terminal and a drain connected to a predetermined DC power supply,
A first P-channel MO whose source is connected to said output
2. The hysteresis circuit according to claim 1, which is formed by an SFET and a third N-channel MOS transistor having a gate connected to the input end, a source connected to the output end, and a drain connected to the output end.
JP16126791A 1991-07-02 1991-07-02 Hysteresis circuit Pending JPH0529895A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP16126791A JPH0529895A (en) 1991-07-02 1991-07-02 Hysteresis circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP16126791A JPH0529895A (en) 1991-07-02 1991-07-02 Hysteresis circuit

Publications (1)

Publication Number Publication Date
JPH0529895A true JPH0529895A (en) 1993-02-05

Family

ID=15731861

Family Applications (1)

Application Number Title Priority Date Filing Date
JP16126791A Pending JPH0529895A (en) 1991-07-02 1991-07-02 Hysteresis circuit

Country Status (1)

Country Link
JP (1) JPH0529895A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010268292A (en) * 2009-05-15 2010-11-25 Yamaha Corp Electronic circuit

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH01278114A (en) * 1988-04-28 1989-11-08 Nec Corp Schmitt input circuit

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH01278114A (en) * 1988-04-28 1989-11-08 Nec Corp Schmitt input circuit

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010268292A (en) * 2009-05-15 2010-11-25 Yamaha Corp Electronic circuit

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