Frequency compensation circuit for stabilising a differential amplifier with cross-coupled transistors

    公开(公告)号:EP0648010A1

    公开(公告)日:1995-04-12

    申请号:EP94202866.3

    申请日:1994-10-04

    IPC分类号: H03F1/08 H03F3/45

    摘要: A differential amplifier comprises a Darlington differential pair (T₁/T₃, T₂/T₄) and a cross-coupled transistor pair (T₅, T₆) to increase the transconductance of the Darlington differential pair (T₁/T₃, T₂/T₄). The negative input impedance of the differential amplifier as a result of the presence of the cross-coupled differential pair (T₅, T₆) is compensated for at high frequencies and the gain of the differential amplifier is reduced by a compensation circuit with a capacitor (30) between the control electrodes of the transistors of the cross-coupled differential pair (T₅, T₆) and with resistors (26, 28) in series with the control electrodes of the transistors of the cross-coupled differential pair (T₅, T₆).

    摘要翻译: 差分放大器包括达林顿差分对(T1 / T3,T2 / T4)和交叉耦合晶体管对(T5,T6),以增加达林顿差分对(T1 / T3,T2 / T4)的跨导。 由于交叉耦合差分对(T5,T6)的存在导致的差分放大器的负输入阻抗在高频下得到补偿,并且差分放大器的增益由具有电容器的补偿电路(30 )与交叉耦合差分对(T5,T6)的晶体管的控制电极串联的电阻(26,28)的交叉耦合差分对(T5,T6)的晶体管的控制电极之间。

    Wideband feedback amplifier
    4.
    发明公开
    Wideband feedback amplifier 失效
    GegengekoppelterBreitbandverstärker。

    公开(公告)号:EP0227323A2

    公开(公告)日:1987-07-01

    申请号:EP86309263.1

    申请日:1986-11-27

    发明人: Nelson, David A.

    IPC分类号: H03F1/48 H03F1/08 H03F3/45

    摘要: Current feedback is employed in differential and unbalanced input wideband feedback amplifiers to render bandwidth and transient response insensitive to closed loop gain over a wide range. In the differential amplifier, two NPN transistors (Qa, Qb) have their emitters connected by a resistor (Ra) and receive input signals (Va, Vb) at their bases. The collectors are connected to a current or voltage mirror, and gain means (A(s)) and a resistor (Rc) are connected between one of the collectors and the emitter of the transistor (Qa).

    摘要翻译: 差分和不平衡输入宽带反馈放大器采用电流反馈,使带宽和瞬态响应对宽范围内的闭环增益不敏感。

    Hochpassschaltung mit Verstärker.
    5.
    发明公开
    Hochpassschaltung mit Verstärker. 失效
    Hochpassschaltung mitVerstärker。

    公开(公告)号:EP0176069A1

    公开(公告)日:1986-04-02

    申请号:EP85112022.0

    申请日:1985-09-23

    IPC分类号: H03H11/12 H03H11/34 H03F3/45

    摘要: Eine zwischen die Emitter einer Differenzverstärkerstufe geschaltete Kapazität (c) entkoppelt die beiden Transistoren (T1, T2) des Differenzverstärkers bis zu einer Grenzfrequenz. An den Anschlüssen der Kapazität (C) lassen sich Änderungen des Gleichtaktsignals und an den Lastwiderständen (R1, R21 der Hochpaßschaltung die verstärkten hochfrequenten Differenzsignale abgreifen und weiterverarbeiten. Verglichen mit herkömmlichen Schaltungen gleicher Funktion ist nur noch eine frequenzbestimmende kapazität (C) erforderlich, die zudem weniger belastet wird.

    摘要翻译: 连接在差分放大器级的发射极之间的电容器(C)将差分放大器的两个晶体管(T1,T2)去耦合到截止频率。 可以在电容器(C)的端子处拾取共模信号的变化,并且可以在高通滤波器的负载电阻器(R1,R2)处拾取放大的高频差分信号,并进一步处理 。 与具有相同功能的常规电路相比,仅需要一个频率确定电容器(C),并且电容器上的负载较小。

    Method and apparatus for vertical compression and decompression of progressive video data
    9.
    发明公开
    Method and apparatus for vertical compression and decompression of progressive video data 有权
    对于逐行视频序列的垂直数据压缩和解压缩的方法和设备

    公开(公告)号:EP1322114A2

    公开(公告)日:2003-06-25

    申请号:EP02258037.7

    申请日:2002-11-21

    IPC分类号: H04N7/00

    摘要: A method and apparatus are disclosed for polyphase filtering a first number of vertical lines of video data to generate a second number of vertical lines of video data and then polyphase filtering the second number of vertical lines of video data to re-create the first number of vertical lines of video data. The first number of vertical lines is larger than the second number of vertical lines. The polyphase filtering of the first number of vertical lines includes low-pass filtering and sample rate converting (down-converting) the first number of vertical lines to the second number of vertical lines. The polyphase filtering of the second number of vertical lines includes sample rate converting (up-sampling) the second number of vertical lines to the first number of vertical lines. Between the down-sampling and the up-sampling, video compression and de-compression may also be performed using, for example, standard compression and de-compression techniques.

    摘要翻译: 一种方法和装置,光盘游离缺失为多相滤波的视频数据的垂直线的第一数量来产生的视频数据的垂直线的第二数目,然后多相滤波的视频数据的垂直线的第二数目来重新创建的第一数量 垂直线的视频数据的。 的垂直线的第一数量大于垂直线的第二数目。 的垂直线的第一数量的多相滤波包括低通滤波和采样率(降频转换)的垂直线的第一数量转换为垂直线的第二数目。 的垂直线的第二数目的多相滤波包括采样率转换(上采样)的垂直线的垂直线的第一数目的第二数目。 的下采样和上采样,视频压缩和解压缩之间可因此使用例如,标准压缩和去压缩技术进行。