公开(公告)号：US20030210086A1

公开(公告)日：2003-11-13

申请号：US10435779

申请日：2003-05-12

Applicant: Broadcom Corporation, a California Corporation

Inventor： Mike Kappes

IPC: H03L005/00

CPC classification number: H03G7/06

Abstract: A circuit and a method for limiting a voltage to a specified value (e.g., a rail voltage) without clipping thereby includes a pair of MOSFETs that turn on when a specified bias voltage is reached to either add to or sink current from the input node of the resistive load responsive to fluctuations in current going through the output resistive load to maintain a constant current through it. A plurality of biasing circuits is provided that control the turn on voltage levels for the MOSFETs to achieve the desired operation. The biasing circuits include circuit components that are matched to circuit components within the circuitry that adds and drains current to the output resistive load including a resistive load that matches the output resistive load.

公开(公告)号：US20040085146A1

公开(公告)日：2004-05-06

申请号：US10695180

申请日：2003-10-28

Applicant: Broadcom Corporation

Inventor： Mike Kappes ,  Terje Gloerstad

IPC: H03B005/20

CPC classification number: H03L7/00 ,  H03B2201/0208 ,  H03B2201/025 ,  H03K3/0231

Abstract: An integrated oscillator that may be used as a time clock includes circuitry that oscillates about an RC time constant, which RC time constant is adjustable to provide a desired frequency of oscillation. More specifically, the oscillator includes a capacitor array that has a plurality of capacitors coupled in parallel wherein each capacitor may be selectively included into the RC time constant or selectively excluded there from. Rather than setting the capacitance values to a desired capacitance value, a system for adjusting the time constant includes circuitry for measuring an output frequency and for comparing that to a certified frequency source wherein the time constant is adjusted by adding or removing capacitors from the capacitor array until the frequency of the internal clock matches an expected frequency.

Abstract translation: 可用作时钟的集成振荡器包括围绕RC时间常数振荡的电路，RC时间常数可调，以提供期望的振荡频率。 更具体地说，振荡器包括电容器阵列，其具有并联耦合的多个电容器，其中每个电容器可被选择性地包括在RC时间常数中或者选择性地被包括在其中。 不是将电容值设置为期望的电容值，而是用于调整时间常数的系统包括用于测量输出频率并与经认证的频率源进行比较的电路，其中通过从电容器阵列中增加或去除电容器来调整时间常数 直到内部时钟的频率与预期频率相匹配。

公开(公告)号：US20030137356A1

公开(公告)日：2003-07-24

申请号：US10052856

申请日：2002-01-18

Applicant: Broadcom Corporation

Inventor： Mike Kappes ,  Terje Gloerstad

IPC: H03L007/00 ,  H03B005/20

CPC classification number: H03L7/00 ,  H03B2201/0208 ,  H03B2201/025 ,  H03K3/0231

Abstract: An integrated oscillator that may be used as a time clock includes circuitry that oscillates about an RC time constant, which RC time constant is adjustable to provide a desired frequency of oscillation. More specifically, the oscillator includes a capacitor array that has a plurality of capacitors coupled in parallel wherein each capacitor may be selectively included into the RC time constant or selectively excluded there from. Rather than setting the capacitance values to a desired capacitance value, a system for adjusting the time constant includes circuitry for measuring an output frequency and for comparing that to a certified frequency source wherein the time constant is adjusted by adding or removing capacitors from the capacitor array until the frequency of the internal clock matches an expected frequency.

Abstract translation: 可用作时钟的集成振荡器包括围绕RC时间常数振荡的电路，RC时间常数可调，以提供期望的振荡频率。 更具体地说，振荡器包括电容器阵列，其具有并联耦合的多个电容器，其中每个电容器可被选择性地包括在RC时间常数中或者选择性地被包括在其中。 不是将电容值设置为期望的电容值，而是用于调整时间常数的系统包括用于测量输出频率并将其与经认证的频率源进行比较的电路，其中通过从电容器阵列中添加或去除电容器来调整时间常数 直到内部时钟的频率与预期频率相匹配。