Path: ...!weretis.net!feeder9.news.weretis.net!tncsrv06.tnetconsulting.net!usenet.blueworldhosting.com!diablo1.usenet.blueworldhosting.com!nnrp.usenet.blueworldhosting.com!.POSTED!not-for-mail From: "Edward Rawde" Newsgroups: sci.electronics.design Subject: Re: Fast monostable with a transistpor array Date: Fri, 14 Jun 2024 12:44:33 -0400 Organization: BWH Usenet Archive (https://usenet.blueworldhosting.com) Lines: 86 Message-ID: References: <8epo6jhf5k5nbkkqp5ot9b6nq1lhoia870@4ax.com> Injection-Date: Fri, 14 Jun 2024 16:44:36 -0000 (UTC) Injection-Info: nnrp.usenet.blueworldhosting.com; logging-data="7458"; mail-complaints-to="usenet@blueworldhosting.com" Cancel-Lock: sha1:CwkavSPuYR0zGM+WFPFzuAGnQJI= sha256:cObwiZbbKI4fNRTBuV6WfIBo8EnoCUcwn61kVrtYZtM= sha1:xSEtXiFyRfJXGJm7JGtYLAC+X04= sha256:eX44Jbvy8e2McPHFom1V/NglScJhZJuOA8LrwlZaj/s= X-RFC2646: Format=Flowed; Original X-MSMail-Priority: Normal X-Priority: 3 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.6157 X-Newsreader: Microsoft Outlook Express 6.00.2900.5931 Bytes: 4950 "john larkin" wrote in message news:viro6jlt7h02ehbsq20em8uv5snn3736up@4ax.com... > On Fri, 14 Jun 2024 12:18:23 -0400, "Edward Rawde" > wrote: > >>"john larkin" wrote in message news:8epo6jhf5k5nbkkqp5ot9b6nq1lhoia870@4ax.com... >>> On Fri, 14 Jun 2024 11:08:56 -0400, "Edward Rawde" >>> wrote: >>> >>>> >>>>"john larkin" wrote in message news:hilo6j9dgctalpiu4v09rpdavf6fetm1cv@4ax.com... >>>>> On Thu, 13 Jun 2024 23:25:37 -0400, "Edward Rawde" >>>>> wrote: >>>>> >>>>>>"Bill Sloman" 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? > > Just pull up some parts from the standard library, some low current > NPNs like BC547 maybe. Look for low capacitances if you care about > that; the HFAs are good in that respect. Yes but BC547 sounds almost as ancient as BC107 Are they still in production? What would work well at a GHz or two or more? > > Why do people avoid making clean 4-wire connections on schematics? Some places have rules about that. I had trouble once, even though I put a very obvious and big blob where the join should have been. When doing schematics of my own I prefer to avoid a one-blob 4-wire join. Use two blobs. > >> >>> >>> 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? > > > There are zillions of single transistors around. I like BCX70 as an > npn gumdrop, although I use mosfets more often for simple things. >