[time-nuts] Buffer / distribution amplifier for TCXO
bruce.griffiths at xtra.co.nz
Wed Aug 4 23:10:59 UTC 2010
Henry Hallam wrote:
> On Wed, Aug 4, 2010 at 1:50 PM, Bruce Griffiths
> <bruce.griffiths at xtra.co.nz> wrote:
>> The TCXO output waveform is presumably a clipped sinewave as required by the
> I posted the waveform at
> Does that count as clipped sine? If not, it seems to work anyway.
Its something like a clipped sine albeit with some ringing as it is clipped.
It more closely resembles a low pass filtered square wave.
>> In which case a linear distribution amplifier is probably required.
>> With only a ~3V supply available, options for the distribution amplifier
>> topology are somewhat limited.
> I'm making a custom board that will include the TCXO and distribution
> amplifier (as well as some digital stuff to allow the 4 receivers to
> communicate), so it can have whatever power supplies it needs.
>> In principle you could use an emitter follower driving 4 other emitter
>> followers with a resistor in series with the emitters of the output devices
>> and the AC coupled loads to match the source to the interconnecting cable
>> impedance to minimise reflections without requiring excessive dissipation in
>> the emitter followers.
>> With the low voltage supply available, using an RF choke is series with the
>> emitter follower's emitter to ground resistor will also be useful in
>> achieving the required dynamic range.
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