ICEM modelling of microcontroller current activity

Better prediction of electromagnetic compatibility (EMC) for components is becoming a topical demand, due to technology improvements. It is requested by integrated circuit (IC) manufacturers as well as by equipment integrators. The French UTE standardisation group has proposed an EMC modelling methodology for ICs, called ICEM (Integrated Circuit Electromagnetic Model). This proposal improves and extends the IBIS standard towards conducted emission prediction (and later radiated emission) by providing additional information modelling the power network and the dynamic current activity of an IC, thus allowing the chip manufacturer to justify the package used as well as the number of power supply pins, and the equipment manufacturer to tune power supply and decoupling networks. After a brief introduction to the ICEM model and the associated methods, this article shows a way of obtaining dynamic current activity models by measuring the current consumed on the IC power supply pins. The use of ICEM for the optimisation of decoupling networks, the evaluation of power supply noise and the tuning of the surface of power and ground planes is presented for the first time with subsequent results.