Real time temperature monitoring of ICs with boundary temperature scan

This paper discusses the possibility of estimating in real time internal heat source temperature values based on the sensor measurements available only at circuit boundaries. The chances and some fundamental limitations of such a boundary temperature scan approach are illustrated based on an example of a test ASIC. This circuit contains a matrix of heat sources which can be individually switched on/off at different power levels. The temperature is monitored by a matrix of sensors located around the circuit layout. The sensor measurements can be processed by on-board digital filters, which provide estimates of heat source temperatures. In particular, the paper focuses on determining the optimal sensor locations, readout time instants and estimation algorithm parameters.