A current noise reduction technique in chopper instrumentation amplifier (CIA) for high-impedance sensor is presented. The proposed technique is based on a time gating method to reduce time varying shot noise which is induced by channel charge injection of chopper switch transistors. An implemented CIA with the proposed time gating technique achieves more than 80-% noise reduction capability.

This paper describes the development of a very low-power pre-amplifier intended for use in pasteless-electrode recording of the human electrocardiogram. The expected input signal range is 100μV 10mV from a lead II electrode configuration. The amplifier provides a gain of 42dB in a 3dB bandwidth of 0.05Hz 2kHz with an input impedance of 280MΩ and a CMRR of greater than 80dB. Its gain and phase c...

We demonstrate a high-performance cryogenic amplifier based on a radio-frequency single-electrontransistor ~rf-SET!. The high charge sensitivity and large bandwidth of the rf-SET, along with low power dissipation, low capacitance and on-chip integrability, make it a good candidate for a general-purpose cryogenic amplifier for high impedance sources. We measure a large-gate rf-SET with an open-l...

We present a miniaturized impedance imaging system, developed for 2D imaging of cell and tissue culture. The system is based on 16 microelectrodes (5 microm x 4 mm). An equivalent circuit for four-point (tetrapolar) impedance spectra was developed and validated. The system uses an Agilent 4294A impedance analyser combined with a front-end amplifier for the impedance measurements. Human epitheli...

The input and output transformers are among the most critical components in the design of a multi-octave amplifier. The total performance of the amplifier (linearity, efficiency, VSWR, gain flatness) will depend on their quality. Transformers with high impedance ratios and for low impedances are more difficult to design in general. In the transmission line transformers very low line impedances ...

A fully-active low-noise amplifier (LNA) for ultrawideband application is presented. Passive on-chip inductor of conventional LNA design is replaced by low-noise active inductor, significantly reducing the total chip area of the proposed CMOS LNA. The core LNA circuit is a cascoded common-source amplifier loaded with an active inductor. Two buffer stages are used to provide the required input a...

In this paper, a design and fabrication of a miniaturized 2.5 GHz 8 W power amplifier using selectively anodized aluminum oxide(SAAO) substrate are presented. The process of SAAO substrate is recently proposed and patented by Wavenics Inc. which uses aluminum as wafer. The selected active device is a commercially available GaN HEMT chip of TriQuint company, which is recently released. The optim...

In this paper, reduced power consumption, low-noise CMOS amplifier using chopper technique is designed, chopper-equalized amplifier had been used as a front end of a voltage-to-frequency converter instrument which performs pretty well, and they were meeting just about every specification, but they had a problem with undesired and unpleasant little offset shifts and jumps. Trying to solve this p...

In this paper, an active compensation method using two current feedback operational amplifiers (CFOAs) to enhance the bandwidth of finite gain inverting voltage amplifier for use as stand-alone amplifier is presented. It is also shown that the inexpensive passive compensation technique can be applied to composite CFOA based amplifier to improve the phase response in addition to bandwidth enhanc...