Built-in temperature sensors for on-line thermal monitoring of microelectronic structures

Built-in temperature sensors increase the system reliability by predicting eventual faults caused by excessive chip temperatures. In this paper, simple and efficient built-in temperature sensors for the on-line thermal monitoring of microelectronic structures are introduced. The proposed temperature sensors produce a signal oscillating at a frequency proportional to the temperature of the microelectronic structure and therefore they are compatible to the oscillation-test method. Design and detailed characteristics of the sensors proposed based on CMOS 1.2 /spl mu/m technology parameters are presented. The fabrication results show a small spread in the nominal oscillation frequency of sensors implemented and a good sensitivity of the oscillation frequency with respect to temperature variations. The sensors proposed require very small power dissipation and silicon area.