公开(公告)号：US06809591B1

公开(公告)日：2004-10-26

申请号：US10457558

申请日：2003-06-10

申请人： Naomi Ohashi

发明人： Naomi Ohashi

IPC分类号： H03G310

CPC分类号： H03G1/007 ,  H03F2203/45466 ,  H03F2203/45641 ,  H03F2203/45671 ,  H03F2203/45672 ,  H03F2203/45691 ,  H03F2203/45702 ,  H03F2203/45722 ,  H03G1/0023 ,  H03G3/3036

摘要： An AGC circuit suitable for applications such as an optical receiving apparatus includes a differential amplification adjustment circuit section for operating on a pair of input signals to produce a corresponding pair of complementary controlled output signals having a fixed amplitude, a peak detector for detecting a peak value of at least one of the controlled output signals, a DC monitoring circuit for detecting the DC level of at least one of the controlled output signals, and an amplitude fixing control circuit for deriving a value of voltage difference between the peak value and DC level and for generating an amplitude control signal based on comparing the voltage difference with a reference voltage. The differential amplification adjustment circuit section applies a degree of amplification that is determined by the amplitude control signal, to thereby perform feedback control of the output signal amplitude. The AGC circuit can further be configured to control the DC levels of the controlled output signals, so that both DC level and amplitude of the controlled output signals are held constant against changes in DC level and amplitude of the input signals.

摘要翻译： 适用于诸如光接收装置之类的应用的AGC电路包括差分放大调节电路部分，用于对一对输入信号进行操作以产生具有固定振幅的相应的互补控制输出信号对，用于检测峰值的峰值检测器 控制输出信号中的至少一个，用于检测受控输出信号中的至少一个的DC电平的DC监视电路，以及用于导出峰值和DC电平之间的电压差值的幅度定影控制电路和 用于基于将电压差与参考电压进行比较来产生幅度控制信号。 差分放大调整电路部分施加由幅度控制信号确定的放大程度，从而执行输出信号幅度的反馈控制。 AGC电路还可以被配置为控制受控输出信号的DC电平，使得受控输出信号的DC电平和幅度保持恒定，抵抗输入信号的DC电平和幅度的变化。

公开(公告)号：US06545537B2

公开(公告)日：2003-04-08

申请号：US09910816

申请日：2001-07-24

申请人： Naomi Ohashi ,  Kazuhiro Nojima

发明人： Naomi Ohashi ,  Kazuhiro Nojima

IPC分类号： H03F345

CPC分类号： H03F3/082 ,  H03F3/45381 ,  H03F2203/45702 ,  H03G1/0029

摘要： In an automatic gain control circuit comprising a variable gain amplifying circuit for amplifying an input signal through the use of variable gain control to send out an output signal and a gain control circuit for amplitude-controlling the input signal fed into the variable gain amplifying circuit, a peak detecting circuit of the variable gain amplifying circuit detects a peak voltage value of the output signal, and the gain control circuit generates an amplitude control signal corresponding to an amplitude value of the output signal. The generated amplitude control signal is fed back to the variable gain amplifying circuit for controlling the amplitude of the output signal to a constant value with respect to amplitude variations of the input signal. With this arrangement, even if a largely amplitude-varying input signal appears, the gain control circuit can control the amplitude of the output signal readily to a constant value.