Supplemental restraint systems (SRS) developed for modern automotive vehicles rely heavily upon microelectronic control circuits; that act within fractions of a second, to coordinate and synchronize the activation, firing and subsequent deployment of airbag safety devices. However, within these vehicles, the relatively harsh electrical environment that exists can often contain multiple sources of transient electrical phenomena, which can give rise to false and potentially fatal activation of the aforementioned safety devices. The need for effective and reliable yet inexpensive built-in microelectronic based transient protection against such occurrences therefore remains key. Historically, automotive microelectronic based transient protection schemes have largely been based upon a technique known as „level-triggered transient protection‟ (LTTP). More recently, the work of Cahill et al. has managed to improve upon the aforementioned approach through use of a technique known as „level-triggered timed shut-off transient protection‟ (LTSOTP). However, from an industrial perspective, all of the advancements reported have remained somewhat unattractive; predominately due to manufacturing complexity, reliability and cost associated issues. In this work, a novel BiCMOS based monolithic HTSOTP device design is proposed that combines the advantages LTTP and LTSOTP, while capable of being „programmed‟ at manufacture to afford transient protection across the entire range of automotive system and sub-system voltage specifications currently in use. Finite element static and dynamic solid-state simulations were used to develop theory of operation for the HTSOTP design proposed and a discrete prototype was assembled and tested to further demonstrate proof of concept. Process simulations were then employed to investigate the constraints and potential issues associated with the realisation of a single monolithic implementation of the aforementioned design. In conclusion, significant advancements in the field of ‘flexible transient protection technologies for low voltage microelectronic switching applications’ have been reported.
|Publication status||Unpublished - 2007|
- Switching Theory