公开(公告)号：US06621362B2

公开(公告)日：2003-09-16

申请号：US09860284

申请日：2001-05-18

Applicant: Afshin Momtaz ,  Armond Hairapetian

Inventor： Afshin Momtaz ,  Armond Hairapetian

IPC: H03L708

CPC classification number: H03J5/244 ,  H03J2200/10 ,  H03L7/099

Abstract: Method and circuitry for implementing VCOs with improved frequency band switching use differentially-coupled varactors to implement the different frequency bands. According to a specific embodiment, one side of a varactor couples to the tank circuit and the other side is coupled either to ground or to the positive power supply VDD without introducing any series parasitic resistance.

公开(公告)号：US06549599B2

公开(公告)日：2003-04-15

申请号：US10095556

申请日：2002-03-11

Applicant: Afshin Momtaz

Inventor： Afshin Momtaz

IPC: H03L7093

CPC classification number: H03L7/089 ,  H03L7/0891 ,  H03L7/093 ,  H03L7/099 ,  H03L7/107 ,  H03L7/18

Abstract: A phase locked loop circuit having a loop filter including a variable resistance for normal loop operation and for fast acquisition has improved stability by defining a loop pole separate from the loop filter. The loop pole remains constant during transition periods of the filter resistance. The loop pole remains constant while loop bandwidth is varied for either phase acquisition or normal operation, and the ratio of bandwidth to pole varies only linearly which makes the phase locked loop more stable during the bandwidth adjustment.

公开(公告)号：US06526113B1

公开(公告)日：2003-02-25

申请号：US09540243

申请日：2000-03-31

Applicant: German Gutierrez ,  Afshin Momtaz

Inventor： German Gutierrez ,  Afshin Momtaz

IPC: H03D324

CPC classification number: H03L7/107 ,  H03L7/089 ,  H03L7/0891 ,  H03L7/093 ,  H03L7/099 ,  H03L7/18

Abstract: Various circuit techniques employ a transconductance (gm) cell in control loops to implement circuits such as phase locked loops and delay locked loops that are capable of operating at ultra high frequencies with improved precision and noise performance. The gm cell is designed to operate on an analog input signal with a very small swing and more gradual transition edges. These characteristics allow implementation of high frequency circuits and systems including, for example, transceivers for fiber optic channels, disk driver electronics and the like.

Abstract translation: 各种电路技术在控制环路中采用跨导（gm）单元来实现诸如锁相环和延迟锁定环路之类的电路，这些电路能够以更高的频率工作，具有改进的精度和噪声性能。 gm单元被设计为在具有非常小的摆动和更渐进的过渡边缘的模拟输入信号上操作。 这些特征允许实现高频电路和系统，包括例如用于光纤通道的收发器，盘驱动器电子等。

公开(公告)号：US06389092B1

公开(公告)日：2002-05-14

申请号：US09615033

申请日：2000-07-12

Applicant: Afshin Momtaz

Inventor： Afshin Momtaz

IPC: H03L7093

CPC classification number: H03L7/089 ,  H03L7/0891 ,  H03L7/093 ,  H03L7/099 ,  H03L7/107 ,  H03L7/18

Abstract: A phase locked loop circuit having a loop filter including a variable resistance for normal loop operation and for fast acquisition has improved stability by defining a loop pole separate from the loop filter. The loop pole remains constant during transition periods of the filter resistance. The loop pole remains constant while loop bandwidth is varied for either phase acquisition or normal operation, and the ratio of bandwidth to pole varies only linearly which makes the phase locked loop more stable during the bandwidth adjustment.

Abstract translation: 具有环路滤波器的锁相环电路，其包括用于正常环路操作和用于快速采集的可变电阻的环路滤波器，通过限定与环路滤波器分离的环极来提高稳定性。 滤波电阻的过渡期间，环极保持恒定。 环路极点保持恒定，而环路带宽为相位采集或正常工作而变化，并且带宽与极点的比率仅线性变化，这使得锁相环在带宽调整期间更加稳定。