CMOS amplifier with integrated tunable band-pass function

Abstract

A CMOS amplifier with integrated tunable band-pass function, a tunable active resistor structure, a method of amplifying an input signal and a method of fabricating an amplifier. The tunable active resistor structure comprises two symmetrically cross-coupled transistors.

Description

technical field [0001] The present invention relates to CMOS amplifiers with integrated adjustable bandpass functionality, adjustable active resistance structures, methods of amplifying input signals and methods of manufacturing amplifiers. Background technique [0002] Biomedical signal acquisition has gained much attention in recent years due to the rapid growth of the market for portable biomedical electronics, such as wearable or implantable health monitoring devices. Subthreshold mode CMOS amplifiers with integrated bandpass functionality are often used in these devices to achieve high power efficiency. In order to effectively reject DC components and baseline drift without distorting the useful biological signal, such amplifiers need to provide a very low high-pass cutoff frequency (below 1 Hz). Together with on-chip capacitors, typically used to generate up to 10 13 A MOS bipolar pseudo-resistor of ohm or higher resistance value is used to implement the high-pass fu...

AI Technical Summary

Problems solved by technology

[0009] While these efforts have been useful in correcting some aspects of the problem in the past, they often show negative effects on others

For example, increasing the linearity of active loads can lead to prolonged settling times and reduced likelihood of post-manufacturing adjustments; on the other hand, including adjustability often introduces increased severe imbalance across the structure and produces reduced linearity and dynamics scope

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