Micro-hot plate temperature control circuit design for a MEMS gas sensor, by interfacing multiphysics and multidomain software.

It is well known that software is a powerful tool for circuit simulation and analysis, conceived to verify electronic systems. However, some kind of analyses may not be completed with only one software suit, due to the nature of the system under test. In this work, a technique is presented to overcome some limitations that are present, in particular, when a simulation has to be done with a system having electrothermal interaction among its components. The system here presented is used in a gas sensor having elements that modify their physical properties upon the operating conditions of the system, mainly biasing and temperature. This existing electrothermal coupling complicates the simulation of the complete system if only one software suite is used. We propose an analysis method that integrates the capacities of the involved programs. Results show that a proposed temperature control circuit operates correctly and this is validated when a complete simulation with two software suites is done, with the system including both, the temperature control circuit and the gas sensor structure. As this structure is very important to the system's performance, the behavior obtained from the integral simulation can determine possible adjustments in the design of the gas sensor system, so fabrication of a prototype through a silicon foundry can proceed.