## Microstrip differential Impedance Calculator

Microstrip are transmission lines that are routed on the external layers of the PCB which are always routed above a large reference plane on the adjacent layer. As the name suggests microstrip lines are used to convey microwave-frequency signals and RF signals. You can read more about microstrip here.

Differential impedance refers to the characteristic impedance between two lines when they are driven differentially (Like USB D+ and D-). To Calculate Input the values of characteristic impedance, trace height, and spacing between traces to obtain precise results. Understand the characteristics of your electrical transmission lines and optimize your circuit design.

##### Step – 1: Calculate the Characteristic Impedance (more Info)
Trace width
mm
Trace thickness
mm
Dielectric thickness
mm
Relative dielectric constant
mm
##### Step – 2: Calculate the differential Impedance
Characteristic Impedance
Ohm
Space Between Traces
mm
Height of Trace
mm

Formula

$d = 2 * z \left( 1 – 0.48 * e^{-0.96 * \left( \frac {s}{h} \right)} \right)$

where :

• d = Differential Impedance
• z = Characteristic Impedance / Single ended Impedance
• s = Space between traces
• h = Height of trace

Any questions? Drop them here!