Ideal Square Wave

Duty cycle = 50%

Peak value = 1 V

Frequency = 1 GHz

Amplitude of nth harmonic An = 2/(n*pi)

All even harmonics are zero.

Self inductance of circular loop of wire

L = 32*R*ln(4R/D) nH

where R = radius of loop in inches

D = diameter of wire in inches

1U

U is unit of measure for vertical usable space, or height of racks, cabinets. 1U is equal to 1.75 inches (44.45mm).

Example : Form-factor of 3U cPCI board is 100mm x 160mm

Form-factor of 6U cPCI board is 100mm x 233.35mm

Note: 3U as per the definition is 3 x 44.45 mm = 133.35. But 160mm is defined in the cPCI specifications.

SDRAM page size

Page size refers to the minimum number of column locations that are on any row and
are accessed with a single ACTIVATE command. This is equal to the number of column
locations times the number of DQ on the device.

Page size = (2^col)*bus_width
where,
col = number of column address lines
bus_width = number of data(DQ) lines

Thumb Rule to calculate via inductance

L=5.08h[ln{4h/d)+1] Unit: nH
ln --> natural logarithm
h -- > via length (PCB thickness) Unit: inch
d -- > via diameter in inches Unit: inch