Interview Topics

For the comprehensive topics, see the PDF at the end of the page.

Example Questions

Things to look for:  A good PDN ensures the power supply bus is free of spikes, ripples, and noise for high transient loads such as digital processors.

Things to look for:  When two ceramic capacitors are connected in parallel, the equivalent series resistance (ESR) and equivalent series inductance (ESL) are reduced, while the capacitance is increased. This results in a wider V-shaped impedance curve, with the lowest impedance being lower. In other words, the V curve shifts down.  See below for a  depiction:

3. How do you know you got it right?

Things to look for: Initial estimate (calculate target impedance (Ztarget = voltage rail*%ripple/(0.5*Imax_transient)), run power integrity simulation, correlate with VNA when the PCBA comes back. 

HWE.DESIGN_ System EE Intervew Topics and Study Guide (1).pdf