Zettaone Technologies India PCB Layout Design Engineer Interview Questions and Answers

I have worked with high speed interfaces such as DDR3, PCIe, USB 3.0, and SATA.

• DDR3

• PCIe

• USB 3.0

• SATA

DDR3 and PCIe sections should be placed strategically on the PCB layout to minimize signal interference and optimize performance.

• Place DDR3 and PCIe sections on opposite sides of the PCB to reduce signal interference.

• Ensure proper grounding and power distribution for both sections to maintain signal integrity.

• Follow manufacturer's guidelines for trace lengths, impedance matching, and signal routing for DDR3 and PCIe in...read more

Some signal names in DDR3 and PCIe include DQ, DQS, CLK, ADDR, CMD, RX, TX, etc.

• DQ

• DQS

• CLK

• ADDR

• CMD

• RX

• TX

Routing involves connecting components on a PCB while length tuning ensures signals arrive at the same time.

• Use high-speed design rules to determine trace width, spacing, and impedance

• Route critical signals first to minimize interference

• Use differential pairs for high-speed signals to maintain signal integrity

• Utilize length matching tools in PCB design software to adjust trace lengths

• Consider signal integrity and EMC r...read more

ESD and AC caps are required for protection against electrostatic discharge and filtering of AC noise.

• ESD caps are required to protect sensitive components from damage due to electrostatic discharge.

• AC caps are used for filtering out AC noise and ensuring stable power supply to the circuit.

• ESD caps typically have low capacitance values to quickly discharge any static electricity buildup.

• AC caps are chosen based on the ...read more

Decoupling capacitor is used to stabilize voltage supply by filtering out noise and providing a local energy reserve for integrated circuits.

• Decoupling capacitors are placed close to the power pins of integrated circuits to filter out noise and stabilize the voltage supply.

• They provide a local energy reserve for the ICs to prevent voltage drops during sudden current spikes.

• Decoupling capacitors are essential for high-s...read more