JP2529354B2 - Voltage conversion circuit - Google Patents
Voltage conversion circuitInfo
- Publication number
- JP2529354B2 JP2529354B2 JP63133325A JP13332588A JP2529354B2 JP 2529354 B2 JP2529354 B2 JP 2529354B2 JP 63133325 A JP63133325 A JP 63133325A JP 13332588 A JP13332588 A JP 13332588A JP 2529354 B2 JP2529354 B2 JP 2529354B2
- Authority
- JP
- Japan
- Prior art keywords
- circuit
- signal
- conversion circuit
- voltage conversion
- voltage
- 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.)
- Expired - Lifetime
Links
Landscapes
- Networks Using Active Elements (AREA)
- Amplifiers (AREA)
Description
【発明の詳細な説明】 産業上の利用分野 近年、低周波のアナログ信号を扱う電子回路には、演
算増幅器（以下オペアンプと呼ぶ）が一般的に使われて
いるが、特にデータ通信分野でのアナログ信号処理回路
では、高い信号対雑音比を得る為に回路の電源仕様を±
5Vの両電源と＋5Vの単電源を同一システム上で用いる事
がある。±5V電源系の回路ではアナログ信号は基本的に
0Vを中心に動作しており、＋5V電源系においては基本的
に2.5Vを中心に動作している。従って２つの回路間を接
続する為にはアナログ信号の中心動作電位をシフトさせ
る必要がある。本発明はこの様なアナログ信号の中心動
作電位のシフトを行う電圧変換回路に関するものであ
る。DETAILED DESCRIPTION OF THE INVENTION Industrial Application Field In recent years, an operational amplifier (hereinafter referred to as an operational amplifier) is generally used in an electronic circuit that handles a low-frequency analog signal. In the analog signal processing circuit, the power supply specification of the circuit is ±
5V dual power supply and + 5V single power supply may be used on the same system. In the ± 5V power supply circuit, analog signals are basically
It operates mainly at 0V, and in the + 5V power system, it basically operates around 2.5V. Therefore, in order to connect the two circuits, it is necessary to shift the central operating potential of the analog signal. The present invention relates to a voltage conversion circuit that shifts the central operating potential of such an analog signal.
従来の技術 オペアンプで構成した回路で中心動作電位の異なる回
路間の接続には容量結合をするのが一般的である。2. Description of the Related Art Capacitive coupling is generally used to connect circuits having different central operating potentials in a circuit composed of operational amplifiers.
以下、従来の電圧変換回路について説明する。 The conventional voltage conversion circuit will be described below.
第２図は電圧変換回路を含んだ回路系を示す。１は±
5V電源系交流回路、２は＋5V電源系交流回路、３は電圧
変換回路である。第２図では±5Vから＋5Vへ変換を表わ
しているが、＋5Vから±5Vへの変換も同様である。FIG. 2 shows a circuit system including a voltage conversion circuit. 1 is ±
5V power system AC circuit, 2 is + 5V power system AC circuit, 3 is a voltage conversion circuit. Although FIG. 2 shows the conversion from ± 5V to + 5V, the conversion from + 5V to ± 5V is the same.
第３図は第２図における電圧変換回路２の具体回路を
示すもので、201,202はオペアンプ、203は容量、204は
抵抗である。第３図のオペアンプ201は±5V電源系交流
回路からのアナログ信号vi2が容量203の入力側で劣化し
ない様にバッファアンプとして用いている。オペアンプ
202は＋5V電源系交流回路と容量203,抵抗204を直結した
場合の信号の特性劣化を防ぐ為に設けているバッファア
ンプである。このように２段のバッファアンプに挟まれ
ているため、容量203と抵抗204で構成される回路は±5V
電源系交流回路及び＋5V電源系交流回路の影響は受けな
い。従って、オペアンプ201の入力信号vi2は同一振幅，
同一中心動作電位を持って容量203に供給される。又オ
ペアンプ202の出力信号vo2は＋5V電源系交流回路の中心
動作電位を供給する為に、端子VDに2.5Vの電位を与え＋
5V電源系交流回路の動作点を決めている。ここで容量20
3と抵抗204から成る回路の伝達特性は、 となる。（１）式から、入力信号vi2の中心動作電位は
容量結合の為に後段へは伝わらず、第４図に示す様にVD
の中心動作電位を持った信号に変換されることがわか
る。FIG. 3 shows a specific circuit of the voltage conversion circuit 2 in FIG. 2, in which 201 and 202 are operational amplifiers, 203 is a capacitor, and 204 is a resistor. The operational amplifier 201 shown in FIG. 3 is used as a buffer amplifier so that the analog signal vi 2 from the ± 5V power supply system AC circuit is not deteriorated at the input side of the capacitor 203. Operational amplifier
Reference numeral 202 denotes a buffer amplifier provided to prevent deterioration of signal characteristics when the + 5V power supply AC circuit is directly connected to the capacitor 203 and the resistor 204. Since it is sandwiched between two stages of buffer amplifiers in this way, the circuit composed of capacitor 203 and resistor 204 is ± 5V.
Not affected by power supply AC circuit and + 5V power supply AC circuit. Therefore, the input signal vi 2 of the operational amplifier 201 has the same amplitude,
It is supplied to the capacitor 203 with the same central operating potential. Further, the output signal vo 2 of the operational amplifier 202 supplies a potential of 2.5V to the terminal V D in order to supply the central operating potential of the + 5V power supply system AC circuit,
The operating point of the 5V power supply AC circuit is determined. Here capacity 20
The transfer characteristic of the circuit consisting of 3 and resistor 204 is Becomes (1) from the equation, the center operating potential of the input signal vi 2 is not transmitted to the subsequent stage for capacitive coupling, V D as shown in FIG. 4
It can be seen that the signal is converted into a signal having the central operating potential of.
発明が解決しようとする課題 このように従来の電圧変換回路においても信号の中心
動作電位は変換されるが、（１）式におけるvisinωｔ
なる交流成分が特に低周波域で容量203及び抵抗204によ
り変化し、その変化した結果が出力信号vo2中に現われ
てしまう。つまり伝達特性が第５図に示す様に、入力振
幅レベルに対し低周波域が減衰してしまう。As described above, even in the conventional voltage conversion circuit, the central operating potential of the signal is converted, but in the formula (1), visinωt
The AC component is changed by the capacitor 203 and the resistor 204 especially in the low frequency region, and the changed result appears in the output signal vo 2 . That is, as shown in FIG. 5, the transfer characteristic is attenuated in the low frequency region with respect to the input amplitude level.
本発明はこのような従来の問題を解決する電圧変換回
路を提供することを目的とする。It is an object of the present invention to provide a voltage conversion circuit that solves such conventional problems.
課題を解決するための手段 本発明の電圧変換回路は、非反転入力端子を入力信号
の入力用として用い、出力を自身の反転入力端子に帰還
接続した第１のオペアンプと、非反転入力端子に第１の
オペアンプの出力を第１の抵抗を介し、また自身の出力
を第２の抵抗を介してそれぞれ入力し、非反転入力端子
に電圧VBを入力し、かつ出力端子を出力信号の出力用と
した第２のオペアンプとを備えたものであって、電圧VB
を VB＝（R103・VA＋R104・VC）／（R103＋R104） R103・・・第１の抵抗の抵抗値 R104・・・第２の抵抗の抵抗値 VA・・・入力信号の中心動作電圧 VC・・・出力信号の中心動作電圧 としたものである。Means for Solving the Problems The voltage conversion circuit of the present invention uses a non-inverting input terminal for input of an input signal, and a first operational amplifier in which an output is feedback-connected to its own inverting input terminal and a non-inverting input terminal. The output of the first operational amplifier is input through the first resistor, the output of the first operational amplifier is input through the second resistor, the voltage V B is input to the non-inverting input terminal, and the output terminal outputs the output signal. It is those having a second operational amplifier having a use, the voltage V B
V B = (R 103 · V A + R 104 · V C ) / (R 103 + R 104 ) R 103 ... resistance value of the first resistance R 104 ... resistance value of the second resistance V A ..The central operating voltage of the input signal, V C , is the central operating voltage of the output signal.
作用 このようにすれば電圧変換回路中に容量を用いる必要
がないから、周波数特性を持たさないで交流信号の中心
動作電位をシフトすることができる。By doing so, since it is not necessary to use a capacitor in the voltage conversion circuit, the central operating potential of the AC signal can be shifted without having frequency characteristics.
実 施 例 第１図に本発明の電圧変換回路の一実施例を示す。Practical Example FIG. 1 shows an example of the voltage conversion circuit of the present invention.
第１図において101,102はオペアンプであり、オペア
ンプ102は抵抗103と104とともに反転増幅器を構成して
いる。反転増幅器の利得を“1"とする為に、抵抗103と1
04を同じ値にし、オペアンプ102の反転入力端子には±5
V電源系交流回路からの交流信号を抵抗103を介して入力
する。一方、オペアンプ102の正転入力端子には，±5V
系および＋5V系の２つの交流回路の中心動作電位を考慮
し、分圧抵抗105,106によって次の（２）式で表わされ
る電圧VBを発生し、この電圧VBを加える。In FIG. 1, 101 and 102 are operational amplifiers, and the operational amplifier 102, together with resistors 103 and 104, constitutes an inverting amplifier. In order to set the gain of the inverting amplifier to "1", resistors 103 and 1
Set 04 to the same value, and use ± 5 for the inverting input terminal of operational amplifier 102.
An AC signal from the V power system AC circuit is input via the resistor 103. On the other hand, the non-inverting input terminal of the operational amplifier 102 is ± 5V
Considering the central operating potential of the two AC circuits of the system and the + 5V system, the voltage dividing resistors 105 and 106 generates a voltage V B represented by the following equation (2), adding the voltage V B.
但し、VA,VCはそれぞれ入力信号vi1,出力信号vo1の中
心動作電位、R103,R104はそれぞれ抵抗103,104の抵抗値
である。 However, V A and V C are the central operating potentials of the input signal vi 1 and the output signal vo 1 , respectively, and R 103 and R 104 are the resistance values of the resistors 103 and 104 , respectively.
このVBなる電圧により２つの交流回路間の信号の中心
動作電位が変換されたことになる。さらにこのときの交
流信号の伝達関数は、 となり、低周波域では周波数特性を持たない。This V B voltage means that the central operating potential of the signal between the two AC circuits is converted. Furthermore, the transfer function of the AC signal at this time is Therefore, there is no frequency characteristic in the low frequency range.
発明の効果 以上の様に、本発明によれば、中心動作電位の異なる
２つの交流回路間を直流結合する事により、交流信号に
周波数特性を持たせず中心動作電位をシフトする事が出
来る。EFFECTS OF THE INVENTION As described above, according to the present invention, it is possible to shift the central operating potential without having frequency characteristics in the AC signal by direct-current coupling between the two AC circuits having different central operating potentials.
第１図は本発明の一実施例における電圧変換回路の回路
図、第２図は本発明および従来例における電圧変換回路
を含む交流回路系全体を示す回路構成図、第３図は従来
の電圧変換回路を示す回路図、第４図は第３図の電圧変
換回路で扱う信号波形図、第５図は従来の電圧変換回路
の周波数特性図である。 １……±5V電源系交流回路、２……電圧変換回路、３…
…＋5V電源系交流回路、101……オペアンプ、102〜104
……反転増幅器、105,106……分圧抵抗。FIG. 1 is a circuit diagram of a voltage conversion circuit according to an embodiment of the present invention, FIG. 2 is a circuit configuration diagram showing an entire AC circuit system including the voltage conversion circuit according to the present invention and a conventional example, and FIG. FIG. 4 is a circuit diagram showing a conversion circuit, FIG. 4 is a signal waveform diagram handled by the voltage conversion circuit of FIG. 3, and FIG. 5 is a frequency characteristic diagram of a conventional voltage conversion circuit. 1 ... ± 5V power supply AC circuit, 2 ... voltage conversion circuit, 3 ...
… + 5V power system AC circuit, 101 …… Op Amp, 102-104
…… Inverting amplifier, 105,106 …… Voltage resistance.
Claims (1)
用い、出力を自身の反転入力端子に帰還接続した第１の
オペアンプと、非反転入力端子に前記第１のオペアンプ
の出力を第１の抵抗を介し、また自身の出力を第２の抵
抗を介してそれぞれ入力し、非反転入力端子に電圧VBを
入力し、かつ出力端子を出力信号の出力用とした第２の
オペアンプとを備えたものであって、前記電圧VBを VB＝（R103・VA＋R104・VC）／（R103＋R104） R103・・・第１の抵抗の抵抗値 R104・・・第２の抵抗の抵抗値 VA・・・入力信号の中心動作電圧 VC・・・出力信号の中心動作電圧 とした電圧変換回路。1. A first operational amplifier in which a non-inverting input terminal is used for inputting an input signal, and an output is feedback-connected to its own inverting input terminal, and an output of the first operational amplifier is first in a non-inverting input terminal. Via the second resistor and its own output via the second resistor respectively, the voltage V B is input to the non-inverting input terminal, and the second operational amplifier is used for outputting the output signal from the output terminal. And the voltage V B is V B = (R 103 · V A + R 104 · V C ) / (R 103 + R 104 ) R 103 ... the resistance value of the first resistor R 104 ··· -The resistance value of the second resistor V A --- The central operating voltage of the input signal V C ---- A voltage conversion circuit that uses the central operating voltage of the output signal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63133325A JP2529354B2 (en) | 1988-05-31 | 1988-05-31 | Voltage conversion circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63133325A JP2529354B2 (en) | 1988-05-31 | 1988-05-31 | Voltage conversion circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH01302902A JPH01302902A (en) | 1989-12-06 |
| JP2529354B2 true JP2529354B2 (en) | 1996-08-28 |
Family
ID=15102070
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63133325A Expired - Lifetime JP2529354B2 (en) | 1988-05-31 | 1988-05-31 | Voltage conversion circuit |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2529354B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5749137B2 (en) * | 2011-10-24 | 2015-07-15 | ローム株式会社 | Audio signal processing circuit and electronic device using the same |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6032181B2 (en) * | 1979-09-25 | 1985-07-26 | コニカ株式会社 | electrophotographic photoreceptor |
-
1988
- 1988-05-31 JP JP63133325A patent/JP2529354B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH01302902A (en) | 1989-12-06 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EXPY | Cancellation because of completion of term |