JPH0686377A - Amplification device with protection function - Google Patents
Amplification device with protection functionInfo
- Publication number
- JPH0686377A JPH0686377A JP4233381A JP23338192A JPH0686377A JP H0686377 A JPH0686377 A JP H0686377A JP 4233381 A JP4233381 A JP 4233381A JP 23338192 A JP23338192 A JP 23338192A JP H0686377 A JPH0686377 A JP H0686377A
- Authority
- JP
- Japan
- Prior art keywords
- transistor
- emitter
- output terminal
- inverting amplifier
- amplifier
- 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
Links
Landscapes
- Circuit For Audible Band Transducer (AREA)
Abstract
(57)【要約】
【目的】 ＢＴＬ方式の増幅装置が出力端子を電源の一
方や他方へ短絡することによる破壊から保護する保護機
能付き増幅装置を提供する。
【構成】 増幅部１の反転増幅器２の出力端子４と非反
転増幅器３の出力端子５との間に直列に抵抗７，８を接
続し、抵抗７，８の接続点にトランジスタ９，１１のベ
ースを接続し、トランジスタ９のエミッタにトランジス
タ１０のエミッタを接続し、トランジスタ１１のエミッ
タにトランジスタ１２のエミッタを接続し、トランジス
タ１０，１２のベースに基準電圧１３を接続し、トラン
ジスタ１０，１１のコレクタにトランジスタ１４のベー
スを接続し、トランジスタ１４のエミッタを接地し、コ
レクタをミュート回路１６に接続し、ミュート回路１６
を前記反転増幅器２と非反転増幅器３に接続した。
(57) [Abstract] [PROBLEMS] To provide an amplifying device with a protection function in which a BTL type amplifying device protects an output terminal from being damaged by short-circuiting one or the other of power supplies. [Structure] Resistors 7 and 8 are connected in series between an output terminal 4 of an inverting amplifier 2 of an amplification unit 1 and an output terminal 5 of a non-inverting amplifier 3, and transistors 9 and 11 are connected to a connection point of the resistors 7 and 8. The base is connected, the emitter of the transistor 9 is connected to the emitter of the transistor 9, the emitter of the transistor 12 is connected to the emitter of the transistor 11, the reference voltage 13 is connected to the bases of the transistors 10 and 12, and the The base of the transistor 14 is connected to the collector, the emitter of the transistor 14 is grounded, and the collector is connected to the mute circuit 16.
Was connected to the inverting amplifier 2 and the non-inverting amplifier 3.
Description
【０００１】[0001]
【産業上の利用分野】本発明はＢＴＬ方式の保護機能付
き増幅装置に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a BTL type amplification device with a protection function.
【０００２】[0002]
【従来の技術】ＢＴＬ方式の増幅装置の増幅部１は、図
２に示すように構成されている。反転増幅器２の入力ａ
と非反転増幅器３の入力ｂを接続して駆動信号Ｓを印加
し、反転増幅器２の出力ｃに接続されている第１の出力
端子４と非反転増幅器３の出力ｄに接続されている第２
の出力端子５の間に、負荷６が接続されている。2. Description of the Related Art An amplification section 1 of a BTL type amplification device is constructed as shown in FIG. Input a of the inverting amplifier 2
To the input b of the non-inverting amplifier 3 to apply the drive signal S, and to the first output terminal 4 connected to the output c of the inverting amplifier 2 and the output d of the non-inverting amplifier 3 Two
A load 6 is connected between the output terminals 5 of.
【０００３】このような具体的な使用形態としてはオー
ディオ用のスピーカ駆動回路を例に挙げることができ、
この場合の負荷６はスピーカである。An example of such a specific use form is an audio speaker drive circuit,
The load 6 in this case is a speaker.
【０００４】[0004]
【発明が解決しようとする課題】このような従来の構成
では、ＢＴＬ方式の増幅装置が動作した状態で、第１の
出力端子４または第２の出力端子５を電源の一方
（ＶCC）や電源の他方（接地）に短絡させる障害が発生
すると増幅部１が破壊するおそれがある。In such a conventional configuration, the first output terminal 4 or the second output terminal 5 is connected to one of the power supplies (V CC ) or V CC while the BTL type amplifier is operating. If a short circuit occurs in the other side (ground) of the power supply, the amplification unit 1 may be destroyed.
【０００５】本発明は上記のような障害から増幅部１を
保護できる保護機能付き増幅装置を提供することを目的
とする。An object of the present invention is to provide an amplifying device with a protection function capable of protecting the amplifying section 1 from the above-mentioned obstacles.
【０００６】[0006]
【課題を解決するための手段】本発明の保護機能付き増
幅装置は、ＢＴＬ方式の増幅装置を構成する反転増幅器
の出力端子と非反転増幅器の出力端子との間に直列に第
１，第２の抵抗を接続し、第１，第２の抵抗の接続点に
第１，第２のトランジスタのベースを接続し、第１のト
ランジスタのエミッタに第３のトランジスタのエミッタ
を接続し、第２のトランジスタのエミッタに第４のトラ
ンジスタのエミッタを接続し、第３，第４のトランジス
タのベースに基準電圧を接続し、第２，第３のトランジ
スタのコレクタに第５のトランジスタのベースを接続
し、第５のトランジスタのエミッタを接地し、コレクタ
はミュート回路に接続し、ミュート回路を反転増幅器と
非反転増幅器に接続した保護回路部とを設けたことを特
徴とする。According to another aspect of the present invention, there is provided an amplifier device with a protection function, in which a first and a second amplifier are connected in series between an output terminal of an inverting amplifier and an output terminal of a non-inverting amplifier which constitute the BTL type amplifier. Of the first transistor is connected to the connection point of the first and second resistors, the emitter of the first transistor is connected to the emitter of the third transistor, and the second transistor is connected to the emitter of the third transistor. The emitter of the transistor is connected to the emitter of the fourth transistor, the bases of the third and fourth transistors are connected to the reference voltage, the collectors of the second and third transistors are connected to the base of the fifth transistor, The fifth transistor is characterized in that an emitter is grounded, a collector is connected to a mute circuit, and a protection circuit section in which the mute circuit is connected to an inverting amplifier and a non-inverting amplifier is provided.
【０００７】[0007]
【作用】前記構成により、ＢＴＬ方式の増幅装置の第
１，第２の出力端子間に直列に接続された抵抗の接続点
の電位は、増幅部の第１，第２の出力端子に障害が発生
した場合に変化する。With the above structure, the potential at the connection point of the resistor connected in series between the first and second output terminals of the BTL type amplifying device causes a failure in the first and second output terminals of the amplifying section. It changes when it occurs.
【０００８】したがって、前記抵抗の接続点の電位と基
準電圧を比較することによって異常状態を検出すること
ができ、異常状態を検出したときにミュート回路を動作
させて増幅部を破壊から保護する。Therefore, the abnormal state can be detected by comparing the potential at the connection point of the resistor with the reference voltage, and when the abnormal state is detected, the mute circuit is operated to protect the amplifier section from damage.
【０００９】[0009]
【実施例】以下、本発明の一実施例を図面を参照しなが
ら説明する。なお、従来例を示す図２と同様の作用をな
すものには、同一の符号を付けて説明する。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. It should be noted that components having the same operations as those of the conventional example shown in FIG.
【００１０】図１は、本発明の一実施例における保護機
能付き増幅装置の構成を示す図である。図１に示すよう
に、ＢＴＬ方式の増幅装置を構成する増幅部１の反転増
幅器２の出力端子４と非反転増幅器３の出力端子５との
間に直列に抵抗７，８を接続し、抵抗１，２の接続点に
トランジスタ９，１１のベースを接続し、トランジスタ
９のエミッタにトランジスタ１０のエミッタを接続し、
トランジスタ１１のエミッタにトランジスタ１２のエミ
ッタを接続し、トランジスタ１０，１２のベースに基準
電圧１３を接続し、トランジスタ１０，１１のコレクタ
にトランジスタ１４のベースを接続し、トランジスタ１
４のエミッタを接地し、コレクタをミュート回路１６に
接続し、ミュート回路１６を反転増幅器２と非反転増幅
器３に接続した。FIG. 1 is a diagram showing the configuration of an amplifier device with a protection function according to an embodiment of the present invention. As shown in FIG. 1, resistors 7 and 8 are connected in series between the output terminal 4 of the inverting amplifier 2 and the output terminal 5 of the non-inverting amplifier 3 of the amplifying unit 1 which constitutes the BTL type amplifying device. The bases of the transistors 9 and 11 are connected to the connection point of 1 and 2, and the emitter of the transistor 10 is connected to the emitter of the transistor 9.
The emitter of the transistor 11 is connected to the emitter of the transistor 12, the bases of the transistors 10 and 12 are connected to the reference voltage 13, and the collectors of the transistors 10 and 11 are connected to the base of the transistor 14.
The emitter of 4 was grounded, the collector was connected to the mute circuit 16, and the mute circuit 16 was connected to the inverting amplifier 2 and the non-inverting amplifier 3.
【００１１】以上のように構成された保護機能付き増幅
装置について、以下その動作を説明する。The operation of the amplifying device with protection function configured as described above will be described below.
【００１２】まず、基準電圧１３の電位は増幅部１の入
力に駆動信号Ｓが印加されていないときの出力端子４，
５の電位すなわち出力端子の中点電圧と等しく、一般的
には電源電圧の半分の値である。First, the potential of the reference voltage 13 is the output terminal 4 when the drive signal S is not applied to the input of the amplifier 1.
It is equal to the potential of 5, that is, the midpoint voltage of the output terminal, and is generally half the power supply voltage.
【００１３】増幅部１の出力端子４，５が電源の一方や
他方へ短絡する障害が発生していない正常動作状態で
は、増幅部１の入力に印加された駆動信号Ｓは増幅部１
の利得分だけ増幅されて出力端子４，５間に出力され
る。このときの抵抗７，８の接続点の電位は、前記した
出力端子の中点電圧と等しく、基準電圧１３と電位差を
持たないためトランジスタ１０，１１は動作せず、ミュ
ート回路１６を駆動するトランジスタ１４も動作しない
ので、ミュート回路１６は動作せず、増幅部１は正常動
作を続ける。In a normal operating state in which there is no fault in which the output terminals 4 and 5 of the amplifier unit 1 are short-circuited to one or the other of the power supplies, the drive signal S applied to the input of the amplifier unit 1 is
It is amplified by the gain of and output between the output terminals 4 and 5. At this time, the potential at the connection point of the resistors 7 and 8 is equal to the midpoint voltage of the output terminal and has no potential difference from the reference voltage 13, so that the transistors 10 and 11 do not operate and the transistor that drives the mute circuit 16 is operated. Since 14 also does not operate, the mute circuit 16 does not operate, and the amplification unit 1 continues normal operation.
【００１４】次に、増幅部１の出力端子４，５が電源の
一方や他方へ短絡する障害が発生している異常動作状態
では、抵抗７，８の接続点の電位は、前記した出力端子
の中点電圧とは等しくならず、基準電圧１３との間に電
位差が発生する。この電位差が２倍のＶBE以上となる
と、トランジスタ９，１０またはトランジスタ１１，１
２が動作することによりトランジスタ１４が動作し、ミ
ュート回路１６を駆動する。ミュート回路１６が駆動す
ることにより増幅部１に保護動作がかかり、増幅部１が
破壊から保護される。Next, in the abnormal operating state in which the output terminals 4 and 5 of the amplifying section 1 are short-circuited to one side or the other side of the power source, the potential at the connection point of the resistors 7 and 8 is the above-mentioned output terminal. Is not equal to the midpoint voltage, and a potential difference is generated between it and the reference voltage 13. When this potential difference is equal to or more than double V BE , the transistors 9 and 10 or the transistors 11 and 1 are
When the transistor 2 operates, the transistor 14 operates and drives the mute circuit 16. When the mute circuit 16 is driven, the amplifier 1 is protected and the amplifier 1 is protected from being destroyed.
【００１５】[0015]
【発明の効果】以上のように本発明によれば、ＢＴＬ方
式の増幅装置を構成する反転増幅器の出力端子と非反転
増幅器の出力端子との間に直列に第１，第２の抵抗を接
続し、第１，第２の抵抗の接続点に第１，第２のトラン
ジスタのベースを接続し、第１のトランジスタのエミッ
タに第３のトランジスタのエミッタを接続し、第２のト
ランジスタのエミッタに第４のトランジスタのエミッタ
を接続し、第３，第４のトランジスタのベースに基準電
圧を接続し、第２，第３のトランジスタのコレクタに第
５のトランジスタのベースを接続し、第５のトランジス
タのエミッタを接地し、コレクタをミュート回路に接続
し、ミュート回路を反転増幅器と非反転増幅器に接続し
た保護回路部とを設けたことにより、増幅部の第１，第
２の出力端子が電源の一方や他方へ短絡される障害が発
生した場合に、増幅部の第１，第２の出力端子の間に直
列に接続された第１，第２の抵抗の接続部の電位と基準
電圧との間に電位差が発生する。この電位差が２ＶBE以
上とミュート回路が駆動し増幅部を第１、第２の出力端
子が電源の一方や他方へ短絡される障害が発生した場合
に生じる破壊から保護することができる。As described above, according to the present invention, the first and second resistors are connected in series between the output terminal of the inverting amplifier and the output terminal of the non-inverting amplifier which constitute the BTL type amplifying device. Then, connect the bases of the first and second transistors to the connection point of the first and second resistors, connect the emitter of the third transistor to the emitter of the first transistor, and connect the emitter of the second transistor to the emitter of the second transistor. The emitter of the fourth transistor is connected, the reference voltage is connected to the bases of the third and fourth transistors, the base of the fifth transistor is connected to the collectors of the second and third transistors, and the fifth transistor is connected. Since the emitter is grounded, the collector is connected to the mute circuit, and the mute circuit is provided with the protection circuit section connected to the inverting amplifier and the non-inverting amplifier, the first and second output terminals of the amplification section are electrically connected. When a short circuit to one or the other occurs, the potential of the connection part of the first and second resistors connected in series between the first and second output terminals of the amplification part and the reference voltage A potential difference is generated between the two. When the potential difference is 2 V BE or more, the mute circuit drives and the amplifier can be protected from damage that occurs when a failure occurs in which the first and second output terminals are short-circuited to one or the other of the power supplies.
【図１】本発明の一実施例における保護機能付き増幅装
置の構成図FIG. 1 is a configuration diagram of an amplifier device with a protection function according to an embodiment of the present invention.
【図２】従来の増幅装置の構成図FIG. 2 is a configuration diagram of a conventional amplification device.
１ 増幅部 ２ 反転増幅器 ３ 非反転増幅器 ４ 第１の出力端子 ５ 第２の出力端子 ６ 負荷 ７ 第１の抵抗 ８ 第２の抵抗 ９ 第１のトランジスタ １０ 第３のトランジスタ １１ 第２のトランジスタ １２ 第４のトランジスタ １３ 基準電圧 １４ 第５のトランジスタ １５ 抵抗 １６ ミュート回路 DESCRIPTION OF SYMBOLS 1 amplification part 2 inverting amplifier 3 non-inverting amplifier 4 1st output terminal 5 2nd output terminal 6 load 7 1st resistance 8 2nd resistance 9 1st transistor 10 3rd transistor 11 2nd transistor 12 Fourth transistor 13 Reference voltage 14 Fifth transistor 15 Resistance 16 Mute circuit
Claims (1)
幅器の出力端子と第２の増幅器の出力端子との間に直列
に第１，第２の抵抗を接続し、前記第１，第２の抵抗の
接続点に第１，第２のトランジスタのベースを接続し、
前記第１のトランジスタのエミッタに第３のトランジス
タのエミッタを接続し、前記第２のトランジスタのエミ
ッタに第４のトランジスタのエミッタを接続し、前記第
３，第４のトランジスタのベースに基準電圧を接続し、
前記第２，第３のトランジスタのコレクタに第５のトラ
ンジスタのベースを接続し、前記第５のトランジスタの
エミッタを接地し、コレクタはミュート回路に接続し、
前記ミュート回路を前記第１，第２の増幅器に接続した
保護回路部とを設けた保護機能付き増幅装置。1. A first and a second resistor are connected in series between an output terminal of a first amplifier and an output terminal of a second amplifier constituting a BTL type amplifier, and the first and second resistors are connected in series. Connect the bases of the first and second transistors to the connection point of the two resistors,
The emitter of the third transistor is connected to the emitter of the first transistor, the emitter of the fourth transistor is connected to the emitter of the second transistor, and the reference voltage is applied to the bases of the third and fourth transistors. connection,
The collectors of the second and third transistors are connected to the base of a fifth transistor, the emitter of the fifth transistor is grounded, and the collector is connected to a mute circuit,
An amplifier device with a protection function, comprising: a protection circuit section in which the mute circuit is connected to the first and second amplifiers.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4233381A JPH0686377A (en) | 1992-09-01 | 1992-09-01 | Amplification device with protection function |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4233381A JPH0686377A (en) | 1992-09-01 | 1992-09-01 | Amplification device with protection function |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0686377A true JPH0686377A (en) | 1994-03-25 |
Family
ID=16954212
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4233381A Pending JPH0686377A (en) | 1992-09-01 | 1992-09-01 | Amplification device with protection function |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0686377A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6525611B1 (en) * | 2001-08-01 | 2003-02-25 | Rf Micro Devices, Inc. | Power amplifier protection |
-
1992
- 1992-09-01 JP JP4233381A patent/JPH0686377A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6525611B1 (en) * | 2001-08-01 | 2003-02-25 | Rf Micro Devices, Inc. | Power amplifier protection |
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