Path: ...!Xl.tags.giganews.com!local-1.nntp.ord.giganews.com!nntp.supernews.com!news.supernews.com.POSTED!not-for-mail NNTP-Posting-Date: Fri, 14 Jun 2024 19:57:17 +0000 From: john larkin Newsgroups: sci.electronics.design Subject: Re: Fast monostable with a transistpor array Date: Fri, 14 Jun 2024 12:57:17 -0700 Message-ID: References: <8epo6jhf5k5nbkkqp5ot9b6nq1lhoia870@4ax.com> User-Agent: ForteAgent/8.00.32.1272 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Lines: 90 X-Trace: sv3-1KTheHOTUeIOd9sKG9mKsaA1khvj9HJgTZ45P0hboPsGMeXo+QXCN6VbNQC3KfSoci9ZY/daLfCkbz2!WLL+ZyviZfGhkNoGXDKckr5my6U1Irrb13sEWvROkzuF5eI+X/3/7srOfAV+pRpo3ZP+DGbAik1E!OHc1ew== X-Complaints-To: www.supernews.com/docs/abuse.html X-DMCA-Complaints-To: www.supernews.com/docs/dmca.html X-Abuse-and-DMCA-Info: Please be sure to forward a copy of ALL headers X-Abuse-and-DMCA-Info: Otherwise we will be unable to process your complaint properly X-Postfilter: 1.3.40 Bytes: 5106 On Fri, 14 Jun 2024 15:19:08 -0400, "Edward Rawde" wrote: >"john larkin" wrote in message news:m7uo6jhfuobfcjaps5o6hatlnm6ntnv84m@4ax.com... >> On Fri, 14 Jun 2024 12:44:33 -0400, "Edward Rawde" >> wrote: >> >>>"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? >> >> It was just an example of a library part, but Digikey will sell you a >> million pieces. >> >>>What would work well at a GHz or two or more? >> >> For switching? Tuned RF? > >I meant a specific npn part and maybe also pnp which is not going obsolete. > >> > You can search Mouser or Digikey for a multi-sourced part. Sadly, fast PNPs are mostly going EOL, faster than NPNs. And all the good things, like GaN and SiC and phemts, are n-types. Nature must dislike P-things. Designing with disctetes is educational, but nowadays ICs are the practical winners. Like wideband MMICs for 10 cents, opamps and switching regulators for 15. Gotta move up the abstraction stack.