15/09/2016
Frequently Asked Questions in Interview:-
What is need for a PCB?
• Designs on bread boards or perf boards are cumbersome, to have neat placement of components without jumpers or wires a PCB is designed. It also helps in providing physical stability and overall circuit is more reliable.
What software or EDA tools are you familiar with?
What if schematic symbols and footprints are not available in component library?
• Create them!
How do you verify schematic symbols or footprints?
• cross verify with datasheets, print footprints and match with actual devices before production.
What are basic checks while laying out MCU based design
• Power path:Ensure that the power flow tracks have sufficient trace width.
• Oscillator circuit: Ensure oscillator is placed near to MCU pins. Distance depends on specific MCU. It is done so that MCU receives stable oscillations without noise.
What are basic checks for RF design?
What are units for measuring footprints?
• Millimeter: SMD components
• Mils:Through hole
What is Mil?
• 1 mil is 1/1000 inch.
Why is it used?
The dimensions of most of the through hole components are in mils. e.g pitch between IC pins(100 mils), Width of ICs (300 mil, 600 mil) etc. Hence if measurement of these in mm will not round figures.
