Do we need to consider bond wire impedance??

[zhangljz]

Hello,

In ASIC design, about IO selection, we need to consider IO output impedance and PCB trace impedance, and match them.

How about the bond wire impedance, it also has impedance. How to calculate it and do we need to consider this parameter?

Thank you.

 

[FvM]

Bond wire impedance is considered in IBIS and SPICE models of an IC. For usual signal frequencies, it shows as a small pin series inductance (e.g. <1 nH). It definitely matters for GBit interfaces.

For single ended IO standards, "ground bounce" caused by lead frames and bond wires can be even more problematic.