There used to be a bunch of low-barrier schottky diodes with Cjo << 1 pF and equivalent series resistance < 5 ohms, SC79 package. BAT63 SMS1546 SMS3927 but they seem to be all gone. Strange. SMS3922 is available, with C=0.7 pF and Rs = 9 typ. Maybe I can use a small phemt as a diode. It seems as if quantity-billion ICs keep killing off fast discrete parts. -- If a man will begin with certainties, he shall end with doubts, but if he will be content to begin with doubts he shall end in certainties. Francis Bacon
fast diodes gone
Started by ●January 7, 2022
Reply by ●January 7, 20222022-01-07
John Larkin wrote:> There used to be a bunch of low-barrier schottky diodes with Cjo << 1 > pF and equivalent series resistance < 5 ohms, SC79 package. > > BAT63 > SMS1546 > SMS3927 > > but they seem to be all gone. Strange. > > SMS3922 is available, with C=0.7 pF and Rs = 9 typ. > > Maybe I can use a small phemt as a diode. > > It seems as if quantity-billion ICs keep killing off fast discrete > parts. >You can still get BAT15s. Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics Briarcliff Manor NY 10510 http://electrooptical.net http://hobbs-eo.com
Reply by ●January 7, 20222022-01-07
On Fri, 7 Jan 2022 15:03:14 -0500, Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:>John Larkin wrote: >> There used to be a bunch of low-barrier schottky diodes with Cjo << 1 >> pF and equivalent series resistance < 5 ohms, SC79 package. >> >> BAT63 >> SMS1546 >> SMS3927 >> >> but they seem to be all gone. Strange. >> >> SMS3922 is available, with C=0.7 pF and Rs = 9 typ. >> >> Maybe I can use a small phemt as a diode. >> >> It seems as if quantity-billion ICs keep killing off fast discrete >> parts. >> >You can still get BAT15s.We're stocking SMS7621/BAT15 in the same stock bin now. There looks to be a big difference in Ron, 18 vs 4.5 ohms. I'll have to see what's actually in the bin. Thanks -- If a man will begin with certainties, he shall end with doubts, but if he will be content to begin with doubts he shall end in certainties. Francis Bacon
Reply by ●January 7, 20222022-01-07
On Fri, 07 Jan 2022 12:30:04 -0800, John Larkin <jlarkin@highland_atwork_technology.com> wrote:>On Fri, 7 Jan 2022 15:03:14 -0500, Phil Hobbs ><pcdhSpamMeSenseless@electrooptical.net> wrote: > >>John Larkin wrote: >>> There used to be a bunch of low-barrier schottky diodes with Cjo << 1 >>> pF and equivalent series resistance < 5 ohms, SC79 package. >>> >>> BAT63 >>> SMS1546 >>> SMS3927 >>> >>> but they seem to be all gone. Strange. >>> >>> SMS3922 is available, with C=0.7 pF and Rs = 9 typ. >>> >>> Maybe I can use a small phemt as a diode. >>> >>> It seems as if quantity-billion ICs keep killing off fast discrete >>> parts. >>> >>You can still get BAT15s. > >We're stocking SMS7621/BAT15 in the same stock bin now. There looks to >be a big difference in Ron, 18 vs 4.5 ohms. I'll have to see what's >actually in the bin. > >ThanksBut I can't find BAT15 in SC-79. I might have to use the awful little leadless thing. https://www.mouser.com/ProductDetail/Infineon-Technologies/BAT-15-02LS-E6433?qs=nTClRYuuQBpQitX3%2F947mA%3D%3D -- If a man will begin with certainties, he shall end with doubts, but if he will be content to begin with doubts he shall end in certainties. Francis Bacon
Reply by ●January 7, 20222022-01-07
fredag den 7. januar 2022 kl. 20.18.27 UTC+1 skrev John Larkin:> There used to be a bunch of low-barrier schottky diodes with Cjo << 1 > pF and equivalent series resistance < 5 ohms, SC79 package. > > BAT63+16000 in stock https://www.arrow.com/en/products/bat6302vh6327xtsa1/infineon-technologies-ag?utm_campaign=octopart_2020&utm_currency=USD&utm_keyword=BAT6302VH6327XTSA1&utm_medium=aggregator&utm_content=inv_listing®ion=nac&utm_source=octopart> SMS1546several places with 10s of thousands in stock https://www.digipart.com/part/SMS1546-005LF
Reply by ●January 7, 20222022-01-07
John Larkin wrote:> On Fri, 07 Jan 2022 12:30:04 -0800, John Larkin > <jlarkin@highland_atwork_technology.com> wrote: > >> On Fri, 7 Jan 2022 15:03:14 -0500, Phil Hobbs >> <pcdhSpamMeSenseless@electrooptical.net> wrote: >> >>> John Larkin wrote: >>>> There used to be a bunch of low-barrier schottky diodes with Cjo << 1 >>>> pF and equivalent series resistance < 5 ohms, SC79 package. >>>> >>>> BAT63 >>>> SMS1546 >>>> SMS3927 >>>> >>>> but they seem to be all gone. Strange. >>>> >>>> SMS3922 is available, with C=0.7 pF and Rs = 9 typ. >>>> >>>> Maybe I can use a small phemt as a diode. >>>> >>>> It seems as if quantity-billion ICs keep killing off fast discrete >>>> parts. >>>> >>> You can still get BAT15s. >> >> We're stocking SMS7621/BAT15 in the same stock bin now. There looks to >> be a big difference in Ron, 18 vs 4.5 ohms. I'll have to see what's >> actually in the bin. >> >> Thanks > > But I can't find BAT15 in SC-79. I might have to use the awful little > leadless thing. > > https://www.mouser.com/ProductDetail/Infineon-Technologies/BAT-15-02LS-E6433?qs=nTClRYuuQBpQitX3%2F947mA%3D%3D >They claim that a full reel is _seventy thousand_ diodes! I once did a sampler proto that used two of those in mid-air, hand soldered. Tended to melt about four solder joints at once. Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics Briarcliff Manor NY 10510 http://electrooptical.net http://hobbs-eo.com
Reply by ●January 7, 20222022-01-07
On Fri, 7 Jan 2022 12:40:23 -0800 (PST), Lasse Langwadt Christensen <langwadt@fonz.dk> wrote:>fredag den 7. januar 2022 kl. 20.18.27 UTC+1 skrev John Larkin: >> There used to be a bunch of low-barrier schottky diodes with Cjo << 1 >> pF and equivalent series resistance < 5 ohms, SC79 package. >> >> BAT63 > >+16000 in stock > >https://www.arrow.com/en/products/bat6302vh6327xtsa1/infineon-technologies-ag?utm_campaign=octopart_2020&utm_currency=USD&utm_keyword=BAT6302VH6327XTSA1&utm_medium=aggregator&utm_content=inv_listing®ion=nac&utm_source=octopart >That's cool, 0.75 pF and (eyeball estimate) 5 ohms. I'll get some.>> SMS1546 > >several places with 10s of thousands in stock >https://www.digipart.com/part/SMS1546-005LFLooks like brokered old stock. The -005 is a dual in SOT23. Obsolete too. Thanks -- If a man will begin with certainties, he shall end with doubts, but if he will be content to begin with doubts he shall end in certainties. Francis Bacon
Reply by ●January 7, 20222022-01-07
On Fri, 7 Jan 2022 15:59:57 -0500, Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:>John Larkin wrote: >> On Fri, 07 Jan 2022 12:30:04 -0800, John Larkin >> <jlarkin@highland_atwork_technology.com> wrote: >> >>> On Fri, 7 Jan 2022 15:03:14 -0500, Phil Hobbs >>> <pcdhSpamMeSenseless@electrooptical.net> wrote: >>> >>>> John Larkin wrote: >>>>> There used to be a bunch of low-barrier schottky diodes with Cjo << 1 >>>>> pF and equivalent series resistance < 5 ohms, SC79 package. >>>>> >>>>> BAT63 >>>>> SMS1546 >>>>> SMS3927 >>>>> >>>>> but they seem to be all gone. Strange. >>>>> >>>>> SMS3922 is available, with C=0.7 pF and Rs = 9 typ. >>>>> >>>>> Maybe I can use a small phemt as a diode. >>>>> >>>>> It seems as if quantity-billion ICs keep killing off fast discrete >>>>> parts. >>>>> >>>> You can still get BAT15s. >>> >>> We're stocking SMS7621/BAT15 in the same stock bin now. There looks to >>> be a big difference in Ron, 18 vs 4.5 ohms. I'll have to see what's >>> actually in the bin. >>> >>> Thanks >> >> But I can't find BAT15 in SC-79. I might have to use the awful little >> leadless thing. >> >> https://www.mouser.com/ProductDetail/Infineon-Technologies/BAT-15-02LS-E6433?qs=nTClRYuuQBpQitX3%2F947mA%3D%3D >> >They claim that a full reel is _seventy thousand_ diodes! > >I once did a sampler proto that used two of those in mid-air, hand >soldered. Tended to melt about four solder joints at once. > >Cheers > >Phil HobbsThe BAT63 looks good. My bottom line is low C, low L, and minimum voltage drop at 30 mA, which is about 0.34 volts for the BAT63. The board is laid out for SC79 already. I'm using an SMS7621 now, only about 0.25 pF, but 16 or 18 ohms Rs, depending on which data sheet to believe. These tiny parts are a pain to solder. 63/37 solder can be sudden. Solid or liquid, no gooey phase. -- If a man will begin with certainties, he shall end with doubts, but if he will be content to begin with doubts he shall end in certainties. Francis Bacon
