Re: Fast monostable with a transistpor array

On 14/06/2024 17:03, john larkin wrote:

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!
 

Yeah, there is something very wrong with that transistor model.
Here is an emitter coupled multivib that can run fast. Should be possible somehow to gate it into being a monostable - worst case wrap a latch around it so it runs just one pulse?
Version 4
SHEET 1 2848 1304
WIRE -512 528 -752 528
WIRE -336 528 -512 528
WIRE -336 576 -336 528
WIRE -752 624 -752 528
WIRE -512 672 -512 528
WIRE -336 688 -336 656
WIRE -224 688 -336 688
WIRE -336 720 -336 688
WIRE -336 720 -448 720
WIRE -336 752 -336 720
WIRE -752 800 -752 704
WIRE -656 800 -752 800
WIRE -224 800 -272 800
WIRE -656 832 -656 800
WIRE -224 848 -224 800
WIRE -752 880 -752 800
WIRE -512 880 -512 768
WIRE -448 880 -512 880
WIRE -336 880 -336 848
WIRE -336 880 -384 880
WIRE -512 944 -512 880
WIRE -336 944 -336 880
WIRE -752 1072 -752 960
WIRE -512 1072 -512 1024
WIRE -512 1072 -752 1072
WIRE -336 1072 -336 1024
WIRE -336 1072 -512 1072
FLAG -224 848 0
FLAG -656 832 0
FLAG -224 688 out
SYMBOL VOLTAGE -752 608 R0
SYMATTR InstName V1
SYMATTR Value 5
SYMBOL npn -448 672 M0
SYMATTR InstName Q1
SYMATTR Value 2SC3838K
SYMBOL npn -272 752 M0
SYMATTR InstName Q2
SYMATTR Value 2SC3838K
SYMBOL VOLTAGE -752 864 R0
SYMATTR InstName V2
SYMATTR Value 5
SYMBOL res -352 560 R0
SYMATTR InstName R2
SYMATTR Value 390
SYMBOL cap -384 864 R90
WINDOW 0 0 32 VBottom 2
WINDOW 3 32 32 VTop 2
SYMATTR InstName C1
SYMATTR Value 5p
SYMBOL res -528 928 R0
SYMATTR InstName R3
SYMATTR Value 1k
SYMBOL res -352 928 R0
SYMATTR InstName R4
SYMATTR Value 1k
TEXT -816 1112 Left 0 !.tran 100u
TEXT -120 976 Left 2 ;EPW SED JUN 2024
TEXT -264 1064 Left 2 ;FAST ASTABLE MULTIVIBRATOR
TEXT -120 1032 Left 2 ;EMITTER COUPLED
TEXT -144 848 Left 1 ;TRADITIONALLY SHOWN WITH
TEXT -176 872 Left 1 ;CURRENT SOURCES FOR EMITTERS
TEXT -160 896 Left 1 ;TRY CHANGING R3 R4 FOR 5mA ?
TEXT -152 552 Left 1 ;ALTERNATIVE OUTPUT CAN BE
TEXT -192 576 Left 1 ;TAKEN ACROSS R IN Q1 COLLECTOR
piglet