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Frequently Asked Question

Using the "ADC SNR method", what is the equivalent bandwidth for the jitter specification?

The signal-to-noise ratio is given by:

SNR = -20*log(2*pi*Fa*Tj); where Fa is the analog BW, Tj is the time jitter as an RMS value.

The bandwidth over which the phase noise is integrated to obtain Tj(rms) is the encode bandwidth. This is not simply Fs/2; it is the bandwidth over which aliased noise components of the encode clock contribute significantly in the equivalent analog input signal bandwidth (Nyquist band). Please see application note AN-756 for more information.