[Coco] What happens if a slow 6809EP is used....

Mike Pepe lamune at doki-doki.net
Tue Jan 19 18:19:05 EST 2010



> -----Original Message-----
> From: coco-bounces at maltedmedia.com [mailto:coco-
> bounces at maltedmedia.com] On Behalf Of jdaggett at gate.net
> Sent: Tuesday, January 19, 2010 1:23 PM
> To: CoCoList for Color Computer Enthusiasts
> Subject: Re: [Coco] What happens if a slow 6809EP is used....
> 
> On 19 Jan 2010 at 6:42, Mike Pepe wrote:
> 
> > It may, I've never tested that, but as an NMOS device the 6809's power
> > dissipation doesn't change much with operating frequency as, say, a
> > CMOS device where the power-to-frequency relationship is far more
> linear.
> 
> Oh yes it does. Swithcing current is determined by the change in voltage
> versus the change in time. This does not matter if it is NMOS, CMOS biCMOS
> or bipolar. NMOS switches faster than CMOS. HCMOS will switch faster than
> NMOS.
> 
> Switching currents are also affected by load capacitances placed onteh
> output of the gate.
> Greater capacitances will also affect rise and fall times within the chip.
> 
> james
> 
 
Sounds like a good excuse to gather some data to me. It would be interesting to see the delta-t at the top of the package when running a test loop at 1 vs. 2 MHz



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