Abstract. We propose a simple isolated link circuit for a multi-channel bio-potential amplifier, by adapting the multiplexing/demultiplexing technique that is generally used in digital circuit design. The reduced number of isolation amplifiers, due to the multiplexing technique, results in an increase in the amount of isolation, as well as a reduction in manufacturing cost. The simple incorporation of a dead-zone in multiplexed timing, and a pull-down resistor in the multiplexed signal line, enables a multiple isolated bio-signal transmission over the shared isolation amplifier, with an affordable inter-channel cross talk.

Keywords: multiplexing, dead-zone, pull-down resistor, isolation, multi-channel bio-potential amplifier

Print publication: Issue 2 (May 2002)
Received 29 January 2002, in final form 25 March 2002
Published 19 April 2002