CID Technology & Digital Tools 3

Question 1

What is the role of an IBIS (Input/Output Buffer Information Specification) model in signal integrity simulation?

Accepted Answer

It characterizes the electrical behavior of IC I/O buffers for simulation without revealing IC design details

Answer

IBIS models describe the voltage/current characteristics and timing behavior of IC I/O buffers, enabling accurate signal integrity simulation while protecting IP.

Question 2

A designer is using a PDN (Power Delivery Network) analysis tool. What does this tool primarily evaluate?

Accepted Answer

Voltage drop, current density, and impedance across the power and ground planes

Answer

PDN analysis tools evaluate DC voltage drop (IR drop), current density hotspots, and AC impedance of the power delivery network to ensure stable supply voltages.

Question 3

Which of the following best describes the function of a 'via stub' in high-speed PCB design tools?

Accepted Answer

The unused portion of a drilled via that extends beyond the signal layer, causing resonance issues

Answer

A via stub is the portion of a through-hole via that continues past the target signal layer, creating a parasitic resonance that degrades high-speed signals.

Question 4

In EDA software, what does the term 'forward annotation' refer to?

Accepted Answer

Pushing schematic netlist and component data changes into the PCB layout

Answer

Forward annotation transfers schematic changes (component additions, net modifications) into the PCB layout environment to keep both databases synchronized.

Question 5

What is the purpose of electromagnetic simulation (full-wave EM simulation) in interconnect design?

Accepted Answer

To accurately model parasitic effects of complex 3D structures like connectors and vias at high frequencies

Answer

Full-wave EM simulators solve Maxwell's equations for complex 3D structures, providing accurate S-parameter models of vias, connectors, and discontinuities at high frequencies.

(CID) Certified Interconnect Designer Practice Test

(CID) Certified Interconnect Designer Practice Test

CID Technology & Digital Tools 3