公开(公告)号：US20050134491A1

公开(公告)日：2005-06-23

申请号：US10998521

申请日：2004-11-29

Applicant: Yunteng Huang ,  Bruno Garlepp ,  David Welland

Inventor： Yunteng Huang ,  Bruno Garlepp ,  David Welland

IPC: H03L7/00 ,  H03L7/099 ,  H03M1/00 ,  H03M1/66 ,  H03M3/00

CPC classification number: H03L7/093 ,  H03J2200/10 ,  H03L7/099 ,  H03L7/10 ,  H03L2207/06 ,  H03M7/3011 ,  H03M7/3028 ,  H03M7/3037

Abstract: An exemplary PLL circuit includes a VCO responsive to a plurality of sub-varactor control signals. A digital loop filter for the PLL digitally generates a varactor control word, which is digitally expanded into a plurality of digital values, each of which is conveyed to a corresponding one of a plurality of DACs. A multiplexer is configured to respectively convey the DAC output signals to a group of sub-varactor control signals according to the varactor control word, and to drive remaining sub-varactor control signals to either the full-scale high value or the full-scale low value of the DAC outputs. Each of the DACs preferably includes a hybrid first order/second order sigma-delta modulator, and in certain embodiments, a NRZ-to-RZ coder circuit, and a linear filter circuit.

Abstract translation: 示例性PLL电路包括响应于多个子变容二极管控制信号的VCO。 用于PLL的数字环路滤波器数字地生成变容二极管控制字，其被数字地扩展成多个数字值，每个数字值被传送到多个DAC中的对应的一个。 复用器被配置为根据变容二极管控制字将DAC输出信号分别传送到一组子变容二极管控制信号，并且将剩余的子变容二极管控制信号驱动到满量程高值或满量程低 DAC输出的值。 每个DAC优选地包括混合一阶/二阶Σ-Δ调制器，并且在某些实施例中，NRZ至RZ编码器电路和线性滤波器电路。

公开(公告)号：US20050100104A1

公开(公告)日：2005-05-12

申请号：US10679013

申请日：2003-10-03

Applicant: Timothy Dupuis ,  George Tuttle ,  Jeffrey Scott ,  Navdeep Sooch ,  David Welland

Inventor： Timothy Dupuis ,  George Tuttle ,  Jeffrey Scott ,  Navdeep Sooch ,  David Welland

IPC: H04L7/033 ,  H04L25/06 ,  H04M11/06 ,  H04M19/00 ,  H04L25/00

CPC classification number: H04L25/06 ,  H04L7/033 ,  H04L25/0266 ,  H04M11/06 ,  H04M19/001

Abstract: A digital direct access arrangement (DAA) circuitry may be used to terminate the telephone connections at the user's end that provides a communication path for signals to and from the phone lines. Briefly described, the DAA provides a programmable means for the DC termination for a variety of international phone standards. The invention may also be utilized with means for transmitting and receiving a signal across a capacitive isolation barrier. More particularly, a DC holding circuit is provided in which a programmable DC current limiting mode is available. In the current limiting mode, power may be dissipated in devices external to a DAA integrated circuit. Moreover, much of the power may be dissipated in external passive devices, such as resistors.

Abstract translation: 可以使用数字直接访问布置（DAA）电路来终止在用户端的电话连接，其提供用于到达和来自电话线的信号的通信路径。 简要描述，DAA提供用于各种国际电话标准的DC终端的可编程装置。 本发明还可以用于在电容隔离屏障上传输和接收信号的装置。 更具体地，提供了一种DC可编程直流限流模式可用的直流保持电路。 在限流模式下，功率可能会在DAA集成电路外部的器件中耗散。 此外，大部分功率可能会在外部无源器件（如电阻）中消散。