Integrated upstream amplifier for cable modems and cable set-top boxes
    1.
    发明授权
    Integrated upstream amplifier for cable modems and cable set-top boxes 有权
    用于电缆调制解调器和有线机顶盒的集成上游放大器

    公开(公告)号:US08013768B2

    公开(公告)日:2011-09-06

    申请号:US10163313

    申请日:2002-06-07

    IPC分类号: H03M1/66

    CPC分类号: H03G3/001 H03G1/0088

    摘要: An upstream amplifier is integrated on a substrate with a digital-to-analog converter (DAC) to form an integrated circuit. In an embodiment, a low-pass filter is also integrated on the substrate. The output signal level of the upstream amplifier is controllable. In embodiments, fine adjustments are made to the output signal level of the upstream amplifier by varying a bias current of the DAC. A software control bit is used to switch between a power-on mode of operation and a power-down mode of operation. The upstream amplifier transmits in a burst mode. The power consumption of the upstream amplifier scales with the amplifier's output signal level. A high degree of matching is attained between the positive and negative paths of the upstream amplifier. This provides high immunity from common-mode disturbances such as substrate noise, clock spurs, and glitches caused by a gain change.

    摘要翻译: 上游放大器集成在具有数模转换器(DAC)的基板上,以形成集成电路。 在一个实施例中,低通滤波器也集成在基板上。 上游放大器的输出信号电平是可控的。 在实施例中,通过改变DAC的偏置电流对上游放大器的输出信号电平进行微调。 软件控制位用于在上电操作模式和掉电操作模式之间切换。 上游放大器以突发模式发送。 上游放大器的功耗随放大器的输出信号电平而变化。 在上游放大器的正和负路径之间达到高度的匹配。 这提供了诸如衬底噪声,时钟刺激和由增益变化引起的毛刺等共模干扰的高抗扰性。