Re: Fast monostable with a transistpor array

"john larkin" <jl@650pot.com> wrote in message news:8epo6jhf5k5nbkkqp5ot9b6nq1lhoia870@4ax.com...

On Fri, 14 Jun 2024 11:08:56 -0400, "Edward Rawde"
<invalid@invalid.invalid> wrote:
>

>
"john larkin" <jl@650pot.com> wrote in message news:hilo6j9dgctalpiu4v09rpdavf6fetm1cv@4ax.com...

On Thu, 13 Jun 2024 23:25:37 -0400, "Edward Rawde"
<invalid@invalid.invalid> wrote:
>

"Bill Sloman" <bill.sloman@ieee.org> wrote in message news:v4f2nm$2augj$1@dont-email.me...

One option John Larjkin doesn't seem to have explored is using Renesas HFA3096 five transistor array as basis for his
mononstable
and level shifter.
>
It offers three 8GHz NPN parts and two 5.5GHz PNP parts in a single array.
>
https://www.renesas.com/us/en/document/dst/hfa3046-hfa3096-hfa3127-hfa3128-datasheet?r=494216
>

>
I put the NPN model parameters into a circuit designed by yourself.
It's late now but I got as far as Time step too small.
>

>
That is neither fast nor a monostable.

>
Yes ok it's an astable and certainly not intended to be fast.
It was intended only to see if the model worked. Nothing more.

>
It doesn't work!
>

>

>
There's no reason to use many-GHz parts in micropower circuits. One
reason is that the sim breaks.

>
Most versions of the HFA3046 are obsolete. The only one left at
Digikey costs $12. It would be risky to design around that part.

If it's obsolete or going obsolete then yes it would make no sense to use it.
I would guess that you get to do plenty of work because a manufacturer has suddenly decided to discontinue a part.

Wasn't  HFA originally a Harris part?
>
There are lots of dual (non-monolithic) diodes and bipolars and fets
around, but the monolithic arrays are mostly gone.

What part would you recommend (single or dual) and does it have a working LTSpice model?

>
The duals save space, but aren't well matched so are electrically and
thermally equivalent to buying two separate parts.
>
I wonder if one could design really fast stuff with the HFA3046.
Package parasitics look nasty. And the big package will force ugly PCB
routing. You can plop a single tiny transistor wherever you want.

Yes that is certainly an advantage of single transistors.
Is a suitable single transistor still available for use in new designs?

>
The HFA parts are either 5 NPNs or 5 PNPs, which is also awkward.

3096 is three NPN two PNP

>
>
>

>
I do wish people would comment Spice sims properly, with author, date,
and what-the-hell-this-actually-is-supposed-to-do.
>
>
I wonder what happened to James. I think all the flaming here drove
him away. James was fun. He always skis in short pants.
>