Analog Layout Design Engineer Interview Questions and Answers

Explanation of various analog layout design concepts including latch up, lod, antenna effect, wpe, shielding, short channel effects, finfet structure, and matching types.

• Latch up is a phenomenon where a parasitic thyristor is formed in a CMOS circuit, causing a high current flow and potentially damaging the circuit.

• LOD (Latch-up due to Overvoltage) occurs when the voltage on the power supply pins exceeds the maximum allowed voltage.

• Antenna effect is the phenomenon where a met...read more

Antenna effect in layout refers to the phenomenon where a metal trace acts as an antenna, picking up electromagnetic signals and causing unwanted noise or interference.

• Occurs when a metal trace on a layout acts as an antenna, picking up external electromagnetic signals

• Can lead to unwanted noise or interference in the circuit

• Can be mitigated by proper layout techniques such as shielding or grounding

• Common in high-frequency designs where signal integrity is crucial

PMOS is a type of metal-oxide-semiconductor field-effect transistor (MOSFET) where the majority charge carriers are holes.

• PMOS is a type of MOSFET where the majority charge carriers are holes.

• PMOS transistors are used in complementary metal-oxide-semiconductor (CMOS) technology.

• PMOS transistors are turned on when the gate-source voltage is lower than the threshold voltage.

• PMOS transistors have higher resistance and slower switching speeds compared to NMOS transistors.