Facing drift: a comparison of three methods

Drift is a common phenomenon in active sensors and, if left untreated, is g enerally the limiting factor in their performance. It is shown that drift a nd spread in sensor characteristics are tightly interwoven due to finite se nsitivity to biasing parameters. Modem treatments of drift are dynamical un der operating conditions, notably so chopping, the sensitivity variation me thod and the recently introduced van Putten-method. These methods differ in regards to drift-dependence on biasing. In their application to silicon fl ow sensors, the first two reduce but do not eliminate drift. The geometric van Putten-method leaves biasing invariant, which eliminates drift and obta ins uniform sensor-characteristics leaving drift-free operation. (C) 2001 E lsevier Science B.V. All rights reserved.