AN279

Rev. 0.1

7

Spurs that are small and few in number and do not contribute significantly to phase jitter may typically be omitted

from period jitter calculations. This is especially true for low offset frequency spurs. Each significant spur

Each spur's contributions are then added in sum square fashion as follows:

or:

Δ

ϕ

RMS_i

2

() x

2

sin

()

=

Δτ

RMS_i

2

2

π

------

⎝⎠

⎛⎞

2

()

2

sin

()

2

------------L f

i

()

2

sin

()

==

Δt

RMS_TOTAL

2

Δt

RMS_NOISE

2

Δt

RMS_1

2

…Δt

RMS_i

2

…Δt

RMS_N

2

++

+

+

+

=

Δt

RMS_TOTAL

2

Δt

RMS_NOISE

2

Δt

RMS_i

2

i

1

=

N

∑

+

=

Δt

RMS_TOTAL

2

=