Path: ...!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail From: Bill Sloman Newsgroups: sci.electronics.design Subject: Re: another fast one-shot Date: Sat, 22 Jun 2024 17:01:16 +1000 Organization: A noiseless patient Spider Lines: 223 Message-ID: References: <6cmc7j1u7uaaubat2klfqgv3gmibvp6t3j@4ax.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Injection-Date: Sat, 22 Jun 2024 09:01:53 +0200 (CEST) Injection-Info: dont-email.me; posting-host="0cc79a1cee177cc1958fd057bbb5f0c4"; logging-data="3838169"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX19E+/WLJwrY57mEdYM1b9BaB02Nytj6YTI=" User-Agent: Mozilla Thunderbird Cancel-Lock: sha1:IWcT0Tm9DX/PTX9engOx7BfkPbs= X-Antivirus-Status: Clean In-Reply-To: <6cmc7j1u7uaaubat2klfqgv3gmibvp6t3j@4ax.com> Content-Language: en-US X-Antivirus: Norton (VPS 240622-0, 22/6/2024), Outbound message Bytes: 8910 On 22/06/2024 3:20 pm, john larkin wrote: > On Sat, 22 Jun 2024 13:13:44 +1000, Bill Sloman > wrote: > >> On 14/06/2024 1:31 am, john larkin wrote: >>> On Thu, 13 Jun 2024 16:03:04 +1000, Bill Sloman >>> wrote: >>> >>>> On 13/06/2024 4:11 am, john larkin wrote: >>>>> On Wed, 12 Jun 2024 17:22:49 -0000 (UTC), Cursitor Doom >>>>> wrote: >>>>> >>>>>> On Wed, 12 Jun 2024 09:33:17 -0700, john larkin wrote: >>>>>> >>>>>>> Here's another idea for a fast one-shot. This is the just-apply-money >>>>>>> version and should get close to 1 ns pulse width and should easily >>>>>>> trigger at 150 MHz. >>>>>>> >>>>>>> https://www.dropbox.com/scl/fi/1okfo8964bw5m53mjmxs6/ >>>>>> Pecl_One_Shot_1.jpg?rlkey=dwus6qjyqsynl2rv6uje2xxtj&raw=1 >>>>>>> >>>>>>> I can use the other half of the dual comparator elsewhere. This one has >>>>>>> programmable hysteresis too. >>>>>> >>>>>> Exposing my contemptworthy ignorance here no doubt, but what exactly is it >>>>>> that is fast about this design, John? And what would its application be? >>>>> >>>>> It would have a leading-edge prop delay of 350 ps, a minimum pulse >>>>> width just over 1 ns, and would easily trigger at 150 MHz. Integrated >>>>> one-shots, xxx123 types, are always terrible, even the obsolete ECL >>>>> ones. >>>>> >>>>> It would be a programmable delay in a number of possible products, >>>>> including some optical modulators. Just playing right now. >>>>> >>>>> More dollars could certainly do something faster, but as long as >>>>> customers connect boxes with cables, faster isn't worth a lot. Light >>>>> just moves too slow. >>>>> >>>>> Any suggestions for a faster one-shot? >>>> >>>> Version 4 >>>> SHEET 1 2924 1040 >>>> WIRE -592 -720 -768 -720 >>>> WIRE 128 -720 -592 -720 >>>> WIRE 304 -720 128 -720 >>>> WIRE 768 -720 304 -720 >>>> WIRE 976 -720 768 -720 >>>> WIRE 1488 -576 1488 -720 >>>> WIRE 128 -560 128 -720 >>>> WIRE 304 -560 304 -720 >>>> WIRE 768 -560 768 -720 >>>> WIRE -592 -384 -592 -720 >>>> WIRE 1072 -368 1072 -400 >>>> WIRE 768 -320 768 -480 >>>> WIRE 960 -320 768 -320 >>>> WIRE 1008 -320 960 -320 >>>> WIRE 128 -288 128 -480 >>>> WIRE 176 -288 128 -288 >>>> WIRE 576 -288 240 -288 >>>> WIRE 768 -208 768 -320 >>>> WIRE 304 -160 304 -480 >>>> WIRE 400 -160 304 -160 >>>> WIRE 576 -160 576 -288 >>>> WIRE 576 -160 480 -160 >>>> WIRE 640 -160 576 -160 >>>> WIRE 704 -160 640 -160 >>>> WIRE -768 -64 -768 -720 >>>> WIRE 128 48 128 -288 >>>> WIRE -272 96 -432 96 >>>> WIRE 64 96 -192 96 >>>> WIRE 640 128 640 -160 >>>> WIRE 304 160 304 -160 >>>> WIRE -432 240 -432 96 >>>> WIRE -768 416 -768 16 >>>> WIRE -768 416 -880 416 >>>> WIRE -736 416 -768 416 >>>> WIRE -592 416 -592 -320 >>>> WIRE -592 416 -736 416 >>>> WIRE -496 416 -592 416 >>>> WIRE -432 416 -432 320 >>>> WIRE -432 416 -496 416 >>>> WIRE 640 416 640 208 >>>> WIRE 640 416 -432 416 >>>> WIRE 1072 416 640 416 >>>> WIRE 128 464 128 144 >>>> WIRE 768 464 768 -112 >>>> WIRE 768 464 128 464 >>>> WIRE -880 496 -880 416 >>>> WIRE 768 496 768 464 >>>> WIRE -736 640 -736 416 >>>> WIRE -496 640 -496 416 >>>> WIRE -736 656 -736 640 >>>> WIRE -736 944 -736 720 >>>> WIRE -496 944 -496 704 >>>> WIRE -496 944 -736 944 >>>> WIRE 304 944 304 240 >>>> WIRE 304 944 -496 944 >>>> WIRE 768 944 768 576 >>>> WIRE 768 944 304 944 >>>> WIRE 1760 944 768 944 >>>> FLAG -880 496 0 >>>> FLAG 960 -320 out >>>> SYMBOL npn 64 48 R0 >>>> SYMATTR InstName Q1 >>>> SYMATTR Value BFR92A >>>> SYMBOL npn 704 -208 R0 >>>> SYMATTR InstName Q2 >>>> SYMATTR Value BFR92A >>>> SYMBOL voltage -768 -80 R0 >>>> WINDOW 123 0 0 Left 0 >>>> WINDOW 39 24 44 Left 2 >>>> SYMATTR SpiceLine Rser=0.1 >>>> SYMATTR InstName V1 >>>> SYMATTR Value 5.0 >>>> SYMBOL voltage -736 624 R0 >>>> WINDOW 123 0 0 Left 0 >>>> WINDOW 39 24 44 Left 2 >>>> SYMATTR SpiceLine Rser=0.1 >>>> SYMATTR InstName V2 >>>> SYMATTR Value 4.5 >>>> SYMBOL voltage -432 224 R0 >>>> WINDOW 123 0 0 Left 0 >>>> WINDOW 39 0 0 Left 0 >>>> SYMATTR InstName V3 >>>> SYMATTR Value PULSE(0 0.2 1n 300p 300p 100p 200n 2) >>>> SYMBOL res -176 80 R90 >>>> WINDOW 0 0 56 VBottom 2 >>>> WINDOW 3 32 56 VTop 2 >>>> SYMATTR InstName R1 >>>> SYMATTR Value 22 >>>> SYMBOL res 752 480 R0 >>>> SYMATTR InstName R3 >>>> SYMATTR Value 360 >>>> SYMBOL res 112 -576 R0 >>>> SYMATTR InstName R4 >>>> SYMATTR Value 180 >>>> SYMBOL res 624 112 R0 >>>> SYMATTR InstName R5 >>>> SYMATTR Value 43 >>>> SYMBOL res 752 -576 R0 >>>> SYMATTR InstName R6 >>>> SYMATTR Value 180 >>>> SYMBOL res 288 -576 R0 >>>> SYMATTR InstName R2 >>>> SYMATTR Value 1k >>>> SYMBOL cap 240 -304 R90 >>>> WINDOW 0 0 32 VBottom 2 >>>> WINDOW 3 32 32 VTop 2 >>>> SYMATTR InstName C1 >>>> SYMATTR Value 3.3p >>>> SYMBOL res 288 144 R0 >>>> SYMATTR InstName R7 >>>> SYMATTR Value 1k2 >>>> SYMBOL res 496 -176 R90 >>>> WINDOW 0 0 56 VBottom 2 >>>> WINDOW 3 32 56 VTop 2 >>>> SYMATTR InstName R13 >>>> SYMATTR Value 43 >>>> SYMBOL cap -608 -384 R0 >>>> SYMATTR InstName C3 >>>> SYMATTR Value 10n >>>> SYMBOL cap -512 640 R0 >>>> SYMATTR InstName C4 >>>> SYMATTR Value 10n >>>> TEXT -272 1000 Left 2 !.model BFR92A NPN(IS=0.1213E-15 VAF=30 BF=94.73 >>>> IKF=0.46227 XTB=0 BR=10.729 CJC=946.47E-15 CJE=10.416E-15 TR=1.2744E-9 >>>> TF=26.796E-12 ITF=0.0044601 VTF=0.32861 XTF=0.3817 RB=14.998 >>>> RC=0.13793 RE=0.29088 Vceo=15 Icrating=4m mfg=Infineon) >>>> TEXT -904 1024 Left 2 !.tran 0 500n 0 >>>> >>>> It's just a two transistor emitter-coupled monostable, but with the two >>>> transistors as BFR92's run at 10mA, it produces 1nsec pulse without fuss. >>>> ========== REMAINDER OF ARTICLE TRUNCATED ==========