公开(公告)号：US20060103469A1

公开(公告)日：2006-05-18

申请号：US10904578

申请日：2004-11-17

Applicant: Gaurav CHANDRA ,  Prakash EASWARAN ,  Sumantra SETH

Inventor： Gaurav CHANDRA ,  Prakash EASWARAN ,  Sumantra SETH

IPC: H03F3/191

CPC classification number: H03F1/34 ,  H03G3/3052 ,  H03G5/24 ,  H03H11/126 ,  H03H11/1291

Abstract: A low distortion filter circuit implementing variable gain amplification (VGA). An aspect of the present invention increases the degrees of freedom (number of components which can be independently programmed/changed to corresponding desired values) to achieve a desired combination of D.C. gain and filter characteristics (e.g., corner frequency, Q-factor, notch frequency, etc.). Such additional degrees of freedom are attained by including additional components in either an input block or a feedback block (implemented with reference to an operational amplifier), and by redesigning the other block using principles such as admittance cancellation to remove the effects of such additional components. The blocks are designed such that a terminal of the programmable components is connected to a fixed/constant voltage (e.g., ground). Embodiments implementing bi-quad single amplifier with and without notch are disclosed.

Abstract translation: 实现可变增益放大（VGA）的低失真滤波电路。 本发明的一个方面增加了自由度（可以被独立地编程/改变为相应的期望值的分量的数量），以实现期望的DC增益和滤波器特性的组合（例如，转角频率，Q因子，陷波频率 等）。 这样的附加自由度通过将附加组件包括在输入块或反馈块（参考运算放大器实现）中来实现，并且通过使用诸如导纳消除之类的原理重新设计其他块来消除这些附加组件的影响 。 这些块被设计成使得可编程组件的端子连接到固定/恒定电压（例如，接地）。 公开了实现具有和没有陷波的双二极管单放大器的实施例。

公开(公告)号：US20120063041A1

公开(公告)日：2012-03-15

申请号：US13226498

申请日：2011-09-07

Applicant: Sumantra SETH ,  Jayesh Wadekar

Inventor： Sumantra SETH ,  Jayesh Wadekar

IPC: H02H9/04

CPC classification number: H02H9/041

Abstract: A thin-oxide current clamp includes a clamp transistor in current-conducting relation between a voltage-sensitive circuit and a common return of a power supply, the clamp transistor responsive to a sense output signal to provide a low-resistance current flow path from the voltage-sensitive circuit to the common return and thereby clamp a voltage in the voltage-sensitive circuit. The thin-oxide current clamp also includes a current source and a reference current minor, the reference current minor providing a reference current. Further, the thin-oxide current clamp includes a sense current mirror providing a sense current. Further, the thin-oxide current clamp also includes an output transistor that receives the sense current and provides a current flow to a gate of the clamp transistors if the sense current exceeds the reference current.

Abstract translation: 薄氧化物电流钳包括在电压敏感电路和电源的公共返回之间的导通关系中的钳位晶体管，所述钳位晶体管响应于感测输出信号以提供来自所述电源的低电阻电流流动路径 电压敏感电路到公共返回，从而在电压敏感电路中钳位电压。 薄氧化物电流钳还包括电流源和参考电流次要，参考电流次要提供参考电流。 此外，薄氧化物电流钳包括提供感测电流的感测电流镜。 此外，薄氧化物电流钳还包括输出晶体管，其接收感测电流，并且如果感测电流超过参考电流，则向钳位晶体管的栅极提供电流。