ABSTRACT.  

The power delivery network is known to be one of the main sources of emission and immunity problems, as well as the source of subtle reliability issues, in electronic systems using digital and mixed analog and digital integrated circuits components The industry has been very active in the last decades introducing and promoting design techniques and paradigms to address the new technical challenges coming from the industries pursuit of Moore’s Law. Paradigms such as the concept of target impedance for the Power Delivery Network has been introduced, in particular in the world of computer motherboards, and has spread widely in electronics applications. Remarkable works have also been done in the evolution of measurement techniques, in particular on impedance profile versus frequency. However, when applied to Automotive applications and other highly cost sensitive markets these techniques risk overdesign and increased costs. The growing pressure of cost reduction pushes designs towards less expensive manufacturing technologies, such as PCB’s with lower layer count numbers than used in the past and a minimum of external components required by the microprocessors, microcontrollers and System-on-Chip. These challenging trends are particularly visible in Automotive Industry with the increasing reliance on electronics for safety critical systems. There is really a need to maximize the performance from every component placed on the board sent for mass production, being it a microcontroller or a relatively inexpensive ceramic capacitor. Conversely, improper decoupling of the power delivery network can cause both EMC and functional disturbances and in addition increase the susceptibility to externally generated EMC events. Susceptibility is absolutely not welcome in technologies that are used in driver automation assistance such as lane guidance, braking, and other safety and security related systems. With this tutorial we will discuss and demonstrate how the EMC performance of a design can be affected by the decoupling capacitor placement, mounting, case size and the values of the decoupling capacitors. The conclusions arising from these analysis are at times in contradiction to common belief about which decoupling capacitor should be used and how they should be placed.
During the tutorial, we will discuss

• The power delivery system and the constituent components
• Requirements for both DC and AC power delivery
• A systematic approach to decoupling capacitor optimization from both a functional and emissions / immunity perspective
• Power delivery network impedance and it’s relation to time domain switching noise
• Finally we will discuss briefly why the DC power delivery is just as important for EMC as the AC network performance and provide some examples why
   

ABSTRACT. In this section the basics of the power delivery network (PDN) will be covered. We will talk about it's build up and how PDN system requirements are generally defined. From this outset we will talk about how the PDN relates to system noise coupling and how that noise coupling is affected by resonances and component selection. Some real-life examples will be shown where PDN noise issues caused lengthy lab debugging

ABSTRACT. The general findings in the introduction will be put in perspective using measurements on a simple test board. Coupling accross power plane splits and between power plane layers will be illustrated as well as how plane decoupling capacitors and noise isolation components and resonances can be used to affect the noise coupling.

ABSTRACT. Capacitor selection for one of the ST Microcontroller TEM cell boards will be discussed and comparison between different decoupling schemes will be done in both measurements and simulation. The effect of capacitor value selection without any updates to the layout will be quantified using the direct coupling method (IEC61967-4).

ABSTRACT. The final section in this workshop will through a demo and presentation show how capacitor selection can be optimized from a functional as well as noise coupling and immunity perspective