Re: 8051 dead or what?

Jim Granville wrote:

Alistair George wrote:

Ian Bell wrote:

Alistair George wrote:

Re HEF40106BT been there, tried that does not work in our use, which as
a very high gain oscillator.


You are using a hex schmitt trigger as a high gain oscillator?

Ian

Yes, in the original National app notes shows a schmitt trigger as an
oscillator. Variations between manufacturers have largely made that form
of use redundant.

This is curious - I take it you mean something other than the
standard, widely used 2 terminal RC Schmitt oscillator ( or the 3
terminal oscillator, which is more acurate but needs 3 gates of a 40106 )
?


I think he means in a crystal oscillator - ISTR this was a common way of
generating a microprocessor clock in the 80s but even then it was known to
be unreliable due to using a digital device in an analog mode.

Ian
.

Relevant Pages

  • Re: Missing Schmitt Gates??
    ... The NMOS and HMOS MCS-48 oscillator is shown in ... amplifier is a Schmitt Trigger. ... adjacent to the XTAL1 pin. ... Although the MCS48 NMOS chip is LONG past obsolete, ...
    (sci.electronics.design)
  • Re: Whining PWM motor control
    ... What I usually do if it has to be cheap: Take a Schmitt trigger such as the 74HC14 or CD40106, build an oscillator and then quench that with a FET or transistor that is controlled from the feedback point. ... If you want absolutly constant frequency you can build that oscillator and follow with a one-shot that can also be made from a Schmitt gate. ...
    (sci.electronics.design)
  • Re: Missing Schmitt Gates??
    ... I am being a little obtuse here -- the kind of oscillator I was thinking ... I think Ht for Logic with Schmitt inputs is about 1V @ 5V. ... A crystal oscillator using an inverter with hysteresis WILL NOT ... amplifier is a Schmitt Trigger. ...
    (sci.electronics.design)
  • Re: 8051 dead or what?
    ... Jim Granville wrote: ... in the original National app notes shows a schmitt trigger as an oscillator. ...
    (comp.arch.embedded)
  • Re: 8051 dead or what?
    ... You are using a hex schmitt trigger as a high gain oscillator? ... transition depending on parameters) and that configuration isn't seen ...
    (comp.arch.embedded)