JPH05303656A - Oscillation circuit - Google Patents

Oscillation circuit

Info

Publication number
JPH05303656A
JPH05303656A JP4107179A JP10717992A JPH05303656A JP H05303656 A JPH05303656 A JP H05303656A JP 4107179 A JP4107179 A JP 4107179A JP 10717992 A JP10717992 A JP 10717992A JP H05303656 A JPH05303656 A JP H05303656A
Authority
JP
Japan
Prior art keywords
power supply
supply voltage
ring oscillator
internal power
circuit
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.)
Withdrawn
Application number
JP4107179A
Other languages
Japanese (ja)
Inventor
Masahiro Minami
雅弘 南
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 JP4107179A priority Critical patent/JPH05303656A/en
Publication of JPH05303656A publication Critical patent/JPH05303656A/en
Withdrawn legal-status Critical Current

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  • Power Sources (AREA)
  • Microcomputers (AREA)

Abstract

PURPOSE:To reduce the current consumption of an oscillation circuit even if a microcomputer is normally working with the power voltage of a high level by supplying the internal power voltage of a fixed level lower than the working power voltage of the microcomputer and supplied to a ring oscillator from the outside. CONSTITUTION:When a ring oscillator 1 is oscillating, the output of an inverter IV6 is set at a low level and P-channel transistor TR Q1 conducts. At the same time, an N-channel TR Q5 becomes inconductive and an N-channel non- doped TR Q7 also becomes inconductive. Then the voltage is limited to about 2.7V at a contact N1 by an N-channel TR Q4, a P-channel non-doped TR Q3, and an N-channel non-doped TR Q2. Therefore the internal power voltage Vip is fixed at 7V by a TR Q6 even if the external power voltage Vcc exceeds 2.7V.

Description

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

【0001】[0001]

【産業上の利用分野】本発明は発振回路に関し、特に記
憶回路を含むマイクロコンピュータに内蔵される発振回
路に関する。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oscillator circuit, and more particularly to an oscillator circuit built in a microcomputer including a memory circuit.

【0002】[0002]

【従来の技術】従来、紫外線消去型PROM等の記憶回
路を内蔵したマイクロコンピュータにおいては、プログ
ラム待機中、消費電流を低減するため、記憶回路等に高
電圧を供給する昇圧回路の動作を停止させていた。そこ
でこの動作を再開した時に昇圧回路の出力がすぐに使え
るようにするため、発振回路を内蔵していた。
2. Description of the Related Art Conventionally, in a microcomputer having a built-in memory circuit such as an ultraviolet erasable PROM, the operation of a booster circuit that supplies a high voltage to the memory circuit is stopped in order to reduce current consumption while waiting for a program. Was there. Therefore, the oscillator circuit was built in so that the output of the booster circuit could be used immediately when this operation was restarted.

【0003】図4に従来の発振回路の一例を示す。FIG. 4 shows an example of a conventional oscillator circuit.

【0004】この発振回路は、インバータIV1、抵抗
R1及びコンデンサC1による第1の時定数回路、イン
バータIV2、発振制御用のNAND型の論理ゲートG
1、インバータIV3、抵抗R2及びコンデンサC2に
よる第2の時定数回路、インバータIV4をリング状に
縦続接続した発振部分と、インバータIV4の出力を反
転増幅して出力信号OUTとするインバータIV5とを
備えたリング発振器1により構成されていた。
This oscillator circuit comprises an inverter IV1, a first time constant circuit consisting of a resistor R1 and a capacitor C1, an inverter IV2, and a NAND logic gate G for controlling oscillation.
1, an inverter IV3, a second time constant circuit including a resistor R2 and a capacitor C2, an oscillating portion in which an inverter IV4 is cascaded in a ring shape, and an inverter IV5 that inverts and amplifies the output of the inverter IV4 to produce an output signal OUT. And the ring oscillator 1.

【0005】この発振回路のリング発振器1は、外部か
ら供給される電源電圧Vccにより動作し、制御信号C
NTが低レベルのときは発振を停止し、高レベルのとき
所定の周波数で発振する。発振しているときの消費電流
は、図5に示すように、電源電圧Vccが高くなると増
大する。
The ring oscillator 1 of this oscillating circuit operates by a power supply voltage Vcc supplied from the outside, and a control signal C
Oscillation is stopped when NT is at a low level, and oscillates at a predetermined frequency when NT is at a high level. The current consumption during oscillation increases as the power supply voltage Vcc increases, as shown in FIG.

【0006】[0006]

【発明が解決しようとする課題】上述した従来の発振回
路は、外部から供給される電源電圧Vccにより動作す
るリング発振器1で構成されているので、マイクロコン
ピュータ等が通常の動作状態にあり電源電圧が高いと消
費電流が大きいという欠点があった。
Since the above-described conventional oscillation circuit is composed of the ring oscillator 1 which operates by the power supply voltage Vcc supplied from the outside, the microcomputer and the like are in a normal operating state and the power supply voltage is high. Has a drawback that the current consumption is large when is high.

【0007】本発明の目的は、マイクロコンピュータ等
が通常の動作状態にあり電源電圧が高いときでも、消費
電流を低減することができる発振回路を提供することに
ある。
An object of the present invention is to provide an oscillator circuit capable of reducing current consumption even when a microcomputer or the like is in a normal operating state and a power supply voltage is high.

【0008】[0008]

【課題を解決するための手段】本発明の発振回路は、供
給される内部電源電圧により発振するリング発振器と、
外部から供給される電源電圧より低い一定レベルの前記
内部電源電圧を発生し前記リング発振器に供給する定電
圧供給手段と、前記リング発振器の出力信号の振幅を前
記外部から供給される電源電圧と対応するレベルに変換
するレベルシフト回路とを有している。
An oscillator circuit of the present invention includes a ring oscillator that oscillates with an internal power supply voltage supplied,
Constant voltage supply means for generating the internal power supply voltage of a constant level lower than the power supply voltage supplied from the outside and supplying it to the ring oscillator, and the amplitude of the output signal of the ring oscillator corresponding to the power supply voltage supplied from the outside. And a level shift circuit for converting to a level.

【0009】また、定電圧供給手段が、外部からの電源
電圧から所定のレベルの内部電源電圧を発生する回路
や、定電圧供給手段が、リング発振器の内部電源電圧供
給端と接続する端子を設け、この端子に内部電源電圧と
同等レベルの電圧を供給する回路で構成される。
Further, the constant voltage supply means is provided with a circuit for generating an internal power supply voltage of a predetermined level from the power supply voltage from the outside, and the constant voltage supply means is provided with a terminal connected to the internal power supply voltage supply end of the ring oscillator. , A circuit that supplies a voltage at the same level as the internal power supply voltage to this terminal.

【0010】[0010]

【実施例】次に本発明の実施例について図面を参照して
説明する。
Embodiments of the present invention will now be described with reference to the drawings.

【0011】図1は本発明の第1の実施例を示す回路図
である。
FIG. 1 is a circuit diagram showing a first embodiment of the present invention.

【0012】この実施例は、供給される内部電源電圧V
ipにより動作し制御信号CNTが高レベルのとき発振
する従来例と同一構成のリング発振器1と、トランジス
タQ1〜Q7及びインバータIV6を備え制御信号CN
Tが高レベルのとき外部から供給される電源電圧Vcc
(例えば5.0V)より低い一定レベル(例えば2.7
V)の内部電源電圧Vipを発生してリング発振器1に
供給する定電圧発生回路2と、内部電源電圧Vipで動
作しリング発振器1の出力信号を反転増幅するインバー
タIV7、このインバータIV7の出力を反転増幅する
インバータIV8、外部からの電源電圧Vccで動作し
インバータIV7,IV8の出力を差動増幅する差動増
幅器31及びこの差動増幅器31の出力を反転増幅する
インバータIV9を備えリング発振器1の出力信号の振
幅を外部から供給される電源電圧Vccと対応するレベ
ルに変換するレベルシフト回路3とを有する構成となっ
ている。
In this embodiment, the supplied internal power supply voltage V
The control signal CN includes the ring oscillator 1 having the same configuration as that of the conventional example which operates by the ip and oscillates when the control signal CNT is at a high level, the transistors Q1 to Q7 and the inverter IV6.
Power supply voltage Vcc supplied from the outside when T is at high level
Constant level lower than (eg 5.0V) (eg 2.7
V) which generates the internal power supply voltage Vip and supplies it to the ring oscillator 1, the inverter IV7 which operates by the internal power supply voltage Vip and inverts and amplifies the output signal of the ring oscillator 1, and the output of this inverter IV7. The ring oscillator 1 includes an inverter IV8 for inverting and amplifying, a differential amplifier 31 which operates with an external power supply voltage Vcc and differentially amplifies the outputs of the inverters IV7, IV8, and an inverter IV9 for inverting and amplifying the output of the differential amplifier 31. The configuration includes a level shift circuit 3 that converts the amplitude of the output signal into a level corresponding to the power supply voltage Vcc supplied from the outside.

【0013】次にこの実施例の動作について説明する。Next, the operation of this embodiment will be described.

【0014】リング発振器1が発振している時(制御信
号CNTが高レベルの時)インバータIV6の出力は低
レベルとなりPチャネルのトランジスタQ1が導通状態
となり、NチャネルのトランジスタQ5が非導通状態と
なり、Nチャネルノンドープ型のトランジスタQ7(し
きい値電圧が約0.1V)が非導通状態となり、接点N
1はNチャネルのトランジスタQ4とPチャネルノンド
ープ型のトランジスタQ3(しきい値電圧が約−1.9
V)とNチャネルノンドープ型のトランジスタQ2によ
り約2.7Vに電圧制限される。
When the ring oscillator 1 is oscillating (when the control signal CNT is at high level), the output of the inverter IV6 becomes low level, the P-channel transistor Q1 becomes conductive, and the N-channel transistor Q5 becomes non-conductive. , N-channel non-doped transistor Q7 (threshold voltage of about 0.1 V) becomes non-conductive, and contact N
1 is an N-channel transistor Q4 and a P-channel non-doped transistor Q3 (threshold voltage is about -1.9.
V) and the N-channel non-doped transistor Q2 limit the voltage to about 2.7V.

【0015】したがって外部からの電源電圧Vccが
2.7V以上になっても、トランジスタQ6により内部
電源電圧Vipは2.7V一定の電圧となる。
Therefore, even if the external power supply voltage Vcc becomes 2.7 V or higher, the internal power supply voltage Vip becomes constant at 2.7 V due to the transistor Q6.

【0016】また、リング発振器1が発振していない時
(制御信号CNTが低レベルの時)インバータIV6の
出力は高レベルとなりトランジスタQ1が非導通状態と
なり、トランジスタQ5が導通状態となり、節点N1が
0VとなりトランジスタQ6が非導通状態となる。
When the ring oscillator 1 is not oscillating (when the control signal CNT is low level), the output of the inverter IV6 becomes high level, the transistor Q1 becomes non-conductive, the transistor Q5 becomes conductive, and the node N1 becomes The voltage becomes 0V, and the transistor Q6 becomes non-conductive.

【0017】したがって、トランジスタQ7により内部
電源電圧Vipはほぼ外部からの電源電圧Vccと等し
くなる。この時リング発振器1は発振していないので消
費電流の増加は少ない。なお、リング発振器1の出力は
レベルシフト回路3に入力されてその振幅は電源電圧V
ccに変換される。
Therefore, transistor Q7 causes internal power supply voltage Vip to be substantially equal to external power supply voltage Vcc. At this time, since the ring oscillator 1 is not oscillating, the consumption current does not increase so much. The output of the ring oscillator 1 is input to the level shift circuit 3 and its amplitude is the power supply voltage V
converted to cc.

【0018】この実施例においては、外部からの電源電
圧Vccがマイクロコンピュータ等の通常の動作電源電
圧、例えば5Vとなっても、リング発振器1の電源電圧
は内部電源電圧Vipの例えば2.7Vであるので、図
2に示すように、消費電流を低減することができる。ま
た電源電圧Vccが変動しても消費電流は殆んど変化し
ない。
In this embodiment, even if the external power supply voltage Vcc becomes a normal operating power supply voltage of a microcomputer or the like, for example, 5V, the power supply voltage of the ring oscillator 1 is 2.7V of the internal power supply voltage Vip. Therefore, the current consumption can be reduced as shown in FIG. Further, even if the power supply voltage Vcc changes, the consumed current hardly changes.

【0019】図3は本発明の第2の実施例を示す回路図
である。
FIG. 3 is a circuit diagram showing a second embodiment of the present invention.

【0020】この実施例は、低電圧供給手段として、リ
ング発振器1の内部電源電圧供給端と接続する端子To
pを設け、この端子Topに外部から内部電源電圧と同
等レベルの一定の電圧Vopを供給する回路としたもの
である。この実施例では電源電圧Vccに関係なくリン
グ発振器1の消費電を一定に保つことができる。
In this embodiment, as a low voltage supply means, a terminal To connected to the internal power supply voltage supply terminal of the ring oscillator 1 is connected.
p is provided, and a constant voltage Vop having the same level as the internal power supply voltage is externally supplied to this terminal Top. In this embodiment, the power consumption of the ring oscillator 1 can be kept constant regardless of the power supply voltage Vcc.

【0021】[0021]

【発明の効果】以上説明したように本発明は、リング発
振器に、外部から供給されるマイクロコンピュータ等の
動作電源電圧より低い一定の内部電源電圧を供給する構
成とすることにより、マイクロコンピュータ等が通常の
動作状態にあり電源電圧が高いときでも、発振回路の消
費電流を低減することができる効果がある。
As described above, the present invention provides a ring oscillator with a constant internal power supply voltage lower than the operating power supply voltage of a microcomputer or the like supplied from the outside. There is an effect that the current consumption of the oscillation circuit can be reduced even in the normal operation state and the power supply voltage is high.

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

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

【図2】図1に示された実施例の効果を説明するための
消費電流の特性図である。
FIG. 2 is a characteristic diagram of current consumption for explaining the effect of the embodiment shown in FIG.

【図3】本発明の第2の実施例を示す回路図である。FIG. 3 is a circuit diagram showing a second embodiment of the present invention.

【図4】従来の発振回路の一例を示す回路図である。FIG. 4 is a circuit diagram showing an example of a conventional oscillator circuit.

【図5】図4に示された発振回路の課題を説明するため
の消費電流の特性図である。
5 is a characteristic diagram of current consumption for explaining the problem of the oscillation circuit shown in FIG.

【符号の説明】[Explanation of symbols]

1 リング発振器 2 定電圧発生回路 3 レベルシフト回路 31 差動増幅器 G1 論理ゲート IV1〜IV9 インバータ Q1〜Q7 トランジスタ 1 ring oscillator 2 constant voltage generation circuit 3 level shift circuit 31 differential amplifier G1 logic gate IV1-IV9 inverter Q1-Q7 transistor

Claims (3)

【特許請求の範囲】[Claims] 【請求項1】 供給される内部電源電圧により発振する
リング発振器と、外部から供給される電源電圧より低い
一定レベルの前記内部電源電圧を発生し前記リング発振
器に供給する定電圧供給手段と、前記リング発振器の出
力信号の振幅を前記外部から供給される電源電圧と対応
するレベルに変換するレベルシフト回路とを有すること
を特徴とする発振回路。
1. A ring oscillator that oscillates with an internal power supply voltage that is supplied, constant voltage supply means that generates the internal power supply voltage at a constant level lower than the power supply voltage that is externally supplied, and supplies the internal power supply voltage to the ring oscillator, And a level shift circuit for converting the amplitude of the output signal of the ring oscillator into a level corresponding to the power supply voltage supplied from the outside.
【請求項2】 定電圧供給手段が、外部からの電源電圧
から所定のレベルの内部電源電圧を発生する回路である
請求項1記載の発振回路。
2. The oscillator circuit according to claim 1, wherein the constant voltage supply means is a circuit for generating an internal power supply voltage of a predetermined level from an external power supply voltage.
【請求項3】 定電圧供給手段が、リング発振器の内部
電源電圧供給端と接続する端子を設け、この端子に内部
電源電圧と同等レベルの電圧を供給する回路とした請求
項1記載の発振回路。
3. The oscillator circuit according to claim 1, wherein the constant voltage supply means is provided with a terminal connected to an internal power supply voltage supply terminal of the ring oscillator, and a circuit which supplies a voltage of a level equivalent to the internal power supply voltage to this terminal. .
JP4107179A 1992-04-27 1992-04-27 Oscillation circuit Withdrawn JPH05303656A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP4107179A JPH05303656A (en) 1992-04-27 1992-04-27 Oscillation circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP4107179A JPH05303656A (en) 1992-04-27 1992-04-27 Oscillation circuit

Publications (1)

Publication Number Publication Date
JPH05303656A true JPH05303656A (en) 1993-11-16

Family

ID=14452477

Family Applications (1)

Application Number Title Priority Date Filing Date
JP4107179A Withdrawn JPH05303656A (en) 1992-04-27 1992-04-27 Oscillation circuit

Country Status (1)

Country Link
JP (1) JPH05303656A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6091351A (en) * 1998-01-07 2000-07-18 Mitsubishi Denki Kabushiki Kaisha A/D converter and level shifter
JP2007325273A (en) * 2006-06-01 2007-12-13 Samsung Electro Mech Co Ltd Super-low power rc oscillator
US7492232B2 (en) 2002-01-10 2009-02-17 Fujitsu Microelectronics Limited Oscillator circuit, semiconductor device and semiconductor memory device provided with the oscillator circuit, and control method of the oscillator circuit
US7548191B2 (en) 2004-05-31 2009-06-16 Anritsu Corporation Radar oscillator capable of preventing leak of oscillation output

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6091351A (en) * 1998-01-07 2000-07-18 Mitsubishi Denki Kabushiki Kaisha A/D converter and level shifter
US7492232B2 (en) 2002-01-10 2009-02-17 Fujitsu Microelectronics Limited Oscillator circuit, semiconductor device and semiconductor memory device provided with the oscillator circuit, and control method of the oscillator circuit
US7548191B2 (en) 2004-05-31 2009-06-16 Anritsu Corporation Radar oscillator capable of preventing leak of oscillation output
JP2007325273A (en) * 2006-06-01 2007-12-13 Samsung Electro Mech Co Ltd Super-low power rc oscillator
JP4510054B2 (en) * 2006-06-01 2010-07-21 三星電機株式会社 Ultra low power RC oscillator

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Effective date: 19990706