[time-nuts] Temperature and signal amp for 'Bay FE-5680A?

[David]

On Tue, 10 Jan 2012 21:57:49 +1300, Bruce Griffiths
<bruce.griffiths at xtra.co.nz> wrote:

>Hal Murray wrote:
>>
>> The TADD-3 uses 3 AC drivers in parallel, each going through a 51 ohm resistor.  Changing those resistors to 150 ohms should work.  Maybe a bit lower to account for the impedance in the drivers.  I'd probably check it with a scope.
>>    
>That approach doesn't do anything for the Vcc and GND bounce exhibited 
>by the driver chip.
>GND and Vcc bounce is the cause of the high frequency ringing exhibited 
>by the TADD-3 outputs.
>This ringing can even be observed at the outputs of inverters whose 
>inputs are tied low or high in the same package
>
>Damping the crossover current induced transient in the supply leads 
>(bondwire and lead frame) inductance is one way to minimise this.
>A small resistor in series with the Vcc pin often works well, the 
>resistor value being chosen for near critical damping.
>
>Another problem with the TADD-3 is the sharing of a driver chip by 
>different input frequencies which leads to intermodulation between the 2 
>outputs.

I have never seen that much ground bounce before so assumed it was a
termination problem.  Was the driver chip decoupling inadequate?  That
at least would be easy enough to fix.