On-chip testing of MEMS using pseudo-random test sequences

This paper presents a method for an on-chip fast and accurate broadband determination of MEMS behaviour. This technique is based on impulse response (IR) evaluation using pseudo-random Maximum-Length Sequences (MLS). The MLS approach is capable of providing vastly superior dynamic range in comparison to the straightforward technique using an impulse excitation and is thus an optimal solution for measurements in noisy environments and for low-power test signals. The use of a pseudo-random sequence for testing makes the practical on-chip implementation very efficient in terms of the extra hardware required for on-chip testing. We will exemplify this technique for the case of MEMS structures such as cantilevers and bridges, by determining their mechanical and thermal behaviour using just electrical tests.