# Things to be considered when designing via for high speed signals

#### hioyo

##### Member level 2
Dear Team,

This is a general question.
May I know what are the things to be considered when designing VIAs for high speed design

Regards
HAu

Solution
Via impedance is typically specified for single ended wires, a single via embedded by plane copper. If you use two of this vias for your differential pair, they should have 50 ohm impedance each. But more likely the vias of a differential pair are closer together and not completely embedded by copper. Respectively the impedance is different.

#### barry

Height. Width. Hole diameter. Plating thickness. Inductance. Capacitance. Impedance.

hioyo

### hioyo

Points: 2

#### hioyo

##### Member level 2
Height. Width. Hole diameter. Plating thickness. Inductance. Capacitance. Impedance.
Thank you..
If I am designing the via for a 100ohm differential trace then the Via impedance must be 100ohm.Please correct
me if I am wrong

#### FvM

##### Super Moderator
Staff member
There's no thing like a "100 ohm via". Transmission lines have differential and common mode impedance. You are designing a differential transmission line.

hioyo

### hioyo

Points: 2

#### hioyo

##### Member level 2
There's no thing like a "100 ohm via". Transmission lines have differential and common mode impedance. You are designing a differential transmission line.
Okay you mean entire transmission line inculding via should have an impedance of 100ohm.I am I correct

#### FvM

##### Super Moderator
Staff member
Via impedance is typically specified for single ended wires, a single via embedded by plane copper. If you use two of this vias for your differential pair, they should have 50 ohm impedance each. But more likely the vias of a differential pair are closer together and not completely embedded by copper. Respectively the impedance is different.

hioyo

### hioyo

Points: 2

#### Munyua44

##### Junior Member level 3
Dear Team,

This is a general question.
May I know what are the things to be considered when designing VIAs for high speed design

Regards
HAu
The following are the factors that must be considered. Plating thickness
Capacitance.
Hole diameter.
Inductance.
Impedance.
Width
Height.