pichotjm <pichotjm at free.fr> wrote:
Pls, have a look at this description of Signetics 25000 series 9046 XN
It is not always necessary to go to the expense of buying a 25000 series chip.
I found some WOM in my Dec Alphaserver 1000A recently. I'm not interested in
this bleeding-edge stuff (besides its too new to be on-topic here) so I have now
replaced it with some ordinary memory. I wonder if I could get a good price for
the WOM on ebay?
Can you explain me, what is Vff? Is it a good idea to
decrease this voltage
in order to increase reliability?
6.3Vac is a common voltage for valve (tube) filaments. Given that the 25000 series
is implemented in VLSI (Vacuum large scale integration), I suspect Vff is the supply
to the filaments for the integrated valves on the WOM chip.
Decreasing Vff should reduce power dissipation and improve the lifetime of the chip.
However, it may also result in poorer noise immunity.
Either that or Vff is the reference voltage used by the flip-flops and decreasing it
will unbalance the chip by creating an excess of flops over flips.
But what will happen with our 50 Hz european supply?
Typically, these things are designed for the American market with no thought given to
widely used standards in other parts of the world. I suspect we will have to use
motor-generator sets to power this type of circuit. Solid state frequency converters
will not be suitable for the critical power requirements here.
I need help...
(please, answer with simple english)