Class B amplifier
    2.
    发明授权
    Class B amplifier 失效
    B类放大器

    公开(公告)号:US4085382A

    公开(公告)日:1978-04-18

    申请号:US743883

    申请日:1976-11-22

    IPC分类号: H03F3/213 H03F3/26 H04R25/00

    CPC分类号: H03F3/213 H03F3/26 H04R25/502

    摘要: A low level, low power, direct coupled integrated class B amplifier having a dual channel three stage preamplifier and a pair of output transistors, one for each channel. In each channel, a DC negative feedback loop connects the collector of the last stage preamplifier transistor to the base of the first stage preamplifier transistor to regulate the DC levels, and a resistive AC negative feedback loop connects the output transistor collector to the first preamplifier transistor collector to reduce the gain dependence of the channel on the current through the output transistor, thus enabling very low idle currents for the output transistors and also providing low distortion output. The resistor in each AC feedback loop is a floating tub resistor to enable it to be taken more than 0.6 volts above the battery voltage. Common mode rejection is provided for at least two of the three preamplifier transistors of each channel.

    摘要翻译: 具有双通道三级前置放大器和一对输出晶体管的低电平,低功率直接耦合集成B类放大器,每个通道一个。 在每个通道中,直流负反馈环路将最后一级前置放大器晶体管的集电极连接到第一级前置放大器晶体管的基极以调节直流电平,并且电阻式交流负反馈环路将输出晶体管集电极连接到第一前置放大器晶体管 集电极以降低通道对通过输出晶体管的电流的增益依赖性,从而使输出晶体管的空闲电流非常低,并且还提供低失真输出。 每个AC反馈回路中的电阻是一个浮桶电阻,使其能够超过电池电压0.6伏以上。 为每个通道的三个前置放大器晶体管中的至少两个提供共模抑制。

    Method and apparatus for low power operation of an RF wireless modem
    4.
    发明授权
    Method and apparatus for low power operation of an RF wireless modem 有权
    RF无线调制解调器低功耗操作的方法和装置

    公开(公告)号:US06799030B2

    公开(公告)日:2004-09-28

    申请号:US09976703

    申请日:2001-10-11

    IPC分类号: H04B116

    摘要: The present invention provides for a method and apparatus for extending battery life in a radio frequency (“RF”) wireless modem by automatically commanding the RF modem into a low power, auto-sleep-no-coverage mode when coverage is not available. The auto-sleep-no-coverage mode timing is configurable through software parameters in the operating system of the modem. The invention conforms to the Cellular Digital Packet Data (CDPD) Specification and increases the standby time of the device outside the coverage area to that similar to the standby time when the modem is within a coverage area. One embodiment of the present invention uses two software programmable timers and a preferred embodiment of the invention uses three software programmable timers and a counter.

    摘要翻译: 本发明提供一种用于在覆盖不可用时通过自动命令RF调制解调器进入低功率,自动睡眠不覆盖模式来延长射频(“RF”)无线调制解调器的电池寿命的方法和装置。 通过调制解调器操作系统中的软件参数可以配置自动睡眠无覆盖模式时序。 本发明符合蜂窝数字分组数据(CDPD)规范,并且将覆盖区域外的设备的待机时间增加到类似于调制解调器在覆盖区域内的待机时间。 本发明的一个实施例使用两个软件可编程定时器,并且本发明的优选实施例使用三个软件可编程定时器和一个计数器。

    D.C. amplifier for use with low supply voltage
    6.
    发明授权
    D.C. amplifier for use with low supply voltage 失效
    D.C.放大器用于低电源电压

    公开(公告)号:US4034306A

    公开(公告)日:1977-07-05

    申请号:US677632

    申请日:1976-04-16

    IPC分类号: H03F3/213 H04R25/00 H03F3/45

    CPC分类号: H03F3/213 H04R25/00

    摘要: An integrated circuit direct coupled amplifier capable of operating from a single battery cell, has: a differential amplifier input stage having an input transistor and a second transistor; an intermediate gain stage; and an output stage. Signal is fed back from the output stage to the base of the second transistor of the differential amplifier, through a negative feedback circuit. Current sources are connected as loads in the collector circuits of the input transistor of the differential amplifier and the transistor of the intermediate gain stage. The current sources are biased by separate bias sources, to improve stability. The bias source for the intermediate gain stage current source also biases a current source for the feedback circuit. A starting circuit is connected to the bias source for the intermediate gain stage and provides self starting for the current sources. Frequency compensation elements are located in the base-collector circuit of the intermediate gain stage transistor to stabilize the amplifier, and a gain control resistor connected to the base of the second transistor of the differential stage operates by varying the negative feedback in the amplifier.

    摘要翻译: 一种能够从单个电池单元操作的集成电路直接耦合放大器具有:具有输入晶体管和第二晶体管的差分放大器输入级; 中间增益阶段 和输出级。 信号通过负反馈电路从差分放大器的第二晶体管的输出级反馈到基极。 电流源作为负载连接在差分放大器的输入晶体管和中间增益级的晶体管的集电极电路中。 目前的消息来源被单独的偏倚来源所偏好,以提高稳定性。 中间增益级电流源的偏置源还偏置反馈电路的电流源。 启动电路连接到中间增益级的偏置源,并为电流源提供自启动。 频率补偿元件位于中间增益级晶体管的基极集电极电路中以稳定放大器,并且连接到差分级的第二晶体管的基极的增益控制电阻通过改变放大器中的负反馈而工作。