[time-nuts] Sine to LVDS
bruce.griffiths at xtra.co.nz
Fri Sep 9 11:07:56 UTC 2011
Javier Herrero wrote:
> Hello all,
> I think that the same question that has been discuted here a zillion
> times but usually around 10MHz... anyway, what would be the best way
> to convert a sine wave to a LVDS clock (preferably duty cycle 50%) at
> Texas Instruments suggest a LVDS receiver as a comparator
> http://www.ti.com/lit/an/slyt180/slyt180.pdf but time ago this was
> discussed here, and not very favoured due to the high hysteresis of
> the LVDS receivers.
Use a true LVDS comparator (e.g. ADCMP604).
With 1:1 transformer coupled input and a pair of inverse parallel
schottky diodes across the inputs together with series resistors between
the transformer secondary to the comparator inputs should suffice for
inputs of +16dBm or more.
With sufficient input from a low noise source a cycle to cycle jitter of
1-2ps should be feasible.
Sub picosecond jitter is feasible if one cascades a series of low pass
filtered limiter stages.
More information about the time-nuts