DIFFERENTIAL MODE SENSING ARRANGEMENT

摘要

A new architecture front-end for electronic sensing is introduced. The architecture utilizes a fully differential synchronous detector to modulate the received signal. A first chopping circuit is used to modulate the offset of a fully differential amplifier. A second chopping circuit is used to demodulate the outputs from the amplifier to remove its offset. The new architecture does not require the offset to be measured before a measurement is taken as in the prior art through the use of microcontroller based system. The amplifier employed is fully differential and does not require any feedback components thus increasing the ability to reject interference and common mode signals. The architecture is also immune to the impedance imbalances at the front end by employing cross- coupled synchronous detector arrangement. The architecture can be employed in various applications where the detection of low-level signals with specific frequency contents is required.