• Fast PNP?

    From Phil Hobbs@21:1/5 to All on Tue May 10 10:20:56 2022
    Hi, all,

    A couple of years ago the last mainstream maker (NXP) stopped making the
    last fast PNP--the 5-GHz BFT92--thus depriving some of us of valuable
    design space, e.g. for improving the transconductance of FET bootstraps
    by wrapping a much faster PNP around it.

    A BF862 or CPH3910 with a BFT92 wraparound makes a 750-MHz FET with 10x
    the transconductance but about the same noise. Magic.

    I have ~9k BFT92s in stock, so I'm set for anything I might want to do
    myself, but for customer designs it's more of a worry. Not too long
    ago, the NTE2403 was announced, but stock seems to be, *ahem*, thin.

    I ran across this datasheet: <http://www.unisonic.com.tw/datasheet/2SA1977.pdf>, which is marked "preliminary" and dated 2021. It's apparently a closeish second source
    for the long lost Renesas/NEC 2SA1977, which was even faster than the
    BFT92 (8 GHz f_T).

    Anybody know anything about this outfit? I've never heard of them.

    Thanks

    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

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  • From jlarkin@highlandsniptechnology.com@21:1/5 to pcdhSpamMeSenseless@electrooptical. on Tue May 10 07:33:03 2022
    On Tue, 10 May 2022 10:20:56 -0400, Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:

    Hi, all,

    A couple of years ago the last mainstream maker (NXP) stopped making the
    last fast PNP--the 5-GHz BFT92--thus depriving some of us of valuable
    design space, e.g. for improving the transconductance of FET bootstraps
    by wrapping a much faster PNP around it.

    A BF862 or CPH3910 with a BFT92 wraparound makes a 750-MHz FET with 10x
    the transconductance but about the same noise. Magic.

    I have ~9k BFT92s in stock, so I'm set for anything I might want to do >myself, but for customer designs it's more of a worry. Not too long
    ago, the NTE2403 was announced, but stock seems to be, *ahem*, thin.

    I ran across this datasheet: ><http://www.unisonic.com.tw/datasheet/2SA1977.pdf>, which is marked >"preliminary" and dated 2021. It's apparently a closeish second source
    for the long lost Renesas/NEC 2SA1977, which was even faster than the
    BFT92 (8 GHz f_T).

    Anybody know anything about this outfit? I've never heard of them.

    Thanks

    Phil Hobbs

    Here too:

    https://www.digikey.com/en/products/detail/renesas-electronics-america-inc/2SA1977-T1B-A/11550285

    I've had to redesign a few products that used fast pnp's in SOT-89.



    --

    Anybody can count to one.

    - Robert Widlar

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  • From jlarkin@highlandsniptechnology.com@21:1/5 to pcdhSpamMeSenseless@electrooptical. on Tue May 10 08:33:14 2022
    On Tue, 10 May 2022 10:20:56 -0400, Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:

    Hi, all,

    A couple of years ago the last mainstream maker (NXP) stopped making the
    last fast PNP--the 5-GHz BFT92--thus depriving some of us of valuable
    design space, e.g. for improving the transconductance of FET bootstraps
    by wrapping a much faster PNP around it.

    A BF862 or CPH3910 with a BFT92 wraparound makes a 750-MHz FET with 10x
    the transconductance but about the same noise. Magic.

    I have ~9k BFT92s in stock, so I'm set for anything I might want to do >myself, but for customer designs it's more of a worry. Not too long
    ago, the NTE2403 was announced, but stock seems to be, *ahem*, thin.

    I ran across this datasheet: ><http://www.unisonic.com.tw/datasheet/2SA1977.pdf>, which is marked >"preliminary" and dated 2021. It's apparently a closeish second source
    for the long lost Renesas/NEC 2SA1977, which was even faster than the
    BFT92 (8 GHz f_T).

    Anybody know anything about this outfit? I've never heard of them.

    Thanks

    Phil Hobbs

    Here's the output stage of our P400 pulse/delay generator, the one you
    have.

    https://www.dropbox.com/s/gj5252vstfiw9gw/P400_Output_A.pdf?dl=0

    It's packed with obsolete parts. I replaced it with the GaN fet
    mouse-bite thing for the next generation.



    --

    Anybody can count to one.

    - Robert Widlar

    --- SoupGate-Win32 v1.05
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  • From Phil Hobbs@21:1/5 to jlarkin@highlandsniptechnology.com on Tue May 10 11:35:13 2022
    jlarkin@highlandsniptechnology.com wrote:
    On Tue, 10 May 2022 10:20:56 -0400, Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:

    Hi, all,

    A couple of years ago the last mainstream maker (NXP) stopped
    making the last fast PNP--the 5-GHz BFT92--thus depriving some of
    us of valuable design space, e.g. for improving the
    transconductance of FET bootstraps by wrapping a much faster PNP
    around it.

    A BF862 or CPH3910 with a BFT92 wraparound makes a 750-MHz FET with
    10x the transconductance but about the same noise. Magic.

    I have ~9k BFT92s in stock, so I'm set for anything I might want to
    do myself, but for customer designs it's more of a worry. Not too
    long ago, the NTE2403 was announced, but stock seems to be, *ahem*,
    thin.

    I ran across this datasheet:
    <http://www.unisonic.com.tw/datasheet/2SA1977.pdf>, which is
    marked "preliminary" and dated 2021. It's apparently a closeish
    second source for the long lost Renesas/NEC 2SA1977, which was even
    faster than the BFT92 (8 GHz f_T).

    Anybody know anything about this outfit? I've never heard of
    them.


    Here too:

    https://www.digikey.com/en/products/detail/renesas-electronics-america-inc/2SA1977-T1B-A/11550285


    Yeah, there are a fair amount of NOS Renesas ones out there, apparently.
    For licensed designs it would be more comforting to be able to point to current production.

    I've had to redesign a few products that used fast pnp's in SOT-89.

    I have a reel of BFG31s too. (That's only a thousand pieces, of
    course.)

    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

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  • From Phil Hobbs@21:1/5 to jlarkin@highlandsniptechnology.com on Tue May 10 11:40:07 2022
    jlarkin@highlandsniptechnology.com wrote:
    On Tue, 10 May 2022 10:20:56 -0400, Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:

    Hi, all,

    A couple of years ago the last mainstream maker (NXP) stopped making the
    last fast PNP--the 5-GHz BFT92--thus depriving some of us of valuable
    design space, e.g. for improving the transconductance of FET bootstraps
    by wrapping a much faster PNP around it.

    A BF862 or CPH3910 with a BFT92 wraparound makes a 750-MHz FET with 10x
    the transconductance but about the same noise. Magic.

    I have ~9k BFT92s in stock, so I'm set for anything I might want to do
    myself, but for customer designs it's more of a worry. Not too long
    ago, the NTE2403 was announced, but stock seems to be, *ahem*, thin.

    I ran across this datasheet:
    <http://www.unisonic.com.tw/datasheet/2SA1977.pdf>, which is marked
    "preliminary" and dated 2021. It's apparently a closeish second source
    for the long lost Renesas/NEC 2SA1977, which was even faster than the
    BFT92 (8 GHz f_T).

    Anybody know anything about this outfit? I've never heard of them.

    Thanks

    Phil Hobbs

    Here's the output stage of our P400 pulse/delay generator, the one you
    have.

    https://www.dropbox.com/s/gj5252vstfiw9gw/P400_Output_A.pdf?dl=0

    It's packed with obsolete parts. I replaced it with the GaN fet
    mouse-bite thing for the next generation.

    Nice gizmo, though.

    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

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  • From Gerhard Hoffmann@21:1/5 to All on Tue May 10 18:15:26 2022
    Am 10.05.22 um 17:35 schrieb Phil Hobbs:
    jlarkin@highlandsniptechnology.com wrote:
    On Tue, 10 May 2022 10:20:56 -0400, Phil Hobbs
    <pcdhSpamMeSenseless@electrooptical.net> wrote:

    Hi, all,

    A couple of years ago the last mainstream maker (NXP) stopped
    making the last fast PNP--the 5-GHz BFT92--thus depriving some of
    us of valuable design space, e.g. for improving the
    transconductance of FET bootstraps by wrapping a much faster PNP
    around it.

    A BF862 or CPH3910 with a BFT92 wraparound makes a 750-MHz FET with
    10x the transconductance but about the same noise.  Magic.

    I have ~9k BFT92s in stock, so I'm set for anything I might want to
    do myself, but for customer designs it's more of a worry.  Not too
    long ago, the NTE2403 was announced, but stock seems to be, *ahem*,
    thin.

    I ran across this datasheet:
    <http://www.unisonic.com.tw/datasheet/2SA1977.pdf>, which is
    marked "preliminary" and dated 2021.  It's apparently a closeish
    second source for the long lost Renesas/NEC 2SA1977, which was even
    faster than the BFT92 (8 GHz f_T).

    Anybody know anything about this outfit?  I've never heard of
    them.

    I think Renesas is the sum of NEC semi, Hitachi, Harris, Intersil.

    There is still the HFA3096, a transistor array, Si on isolator.
    Some members of this family have 5.5 GHz PNPs, still active.
    It was easy to get them space qualified a few years ago
    for a dual slope time stretcher. In a ceramic flatpack where
    nobody dared to shorten the extra long leads. :-)


    < https://www.digikey.de/de/products/filter/transistoren-bipolar-bjt-hf/283?s=N4IgTCBcDaIBYDMCGBmADATgGwgLoF8g


    Here too:

    https://www.digikey.com/en/products/detail/renesas-electronics-america-inc/2SA1977-T1B-A/11550285



    Yeah, there are a fair amount of NOS Renesas ones out there, apparently.
     For licensed designs it would be more comforting to be able to point to current production.

    I've had to redesign a few products that used fast pnp's in SOT-89.

    I have a reel of BFG31s too. (That's only a thousand pieces, of
    course.)

    #me too. Ask me if you are desperate. I don't need production quantities.

    Is quantitties a word? It should be. Sugestive as hell. :-)

    cheers, Gerhard

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  • From Phil Hobbs@21:1/5 to Gerhard Hoffmann on Tue May 10 12:47:54 2022
    Gerhard Hoffmann wrote:
    Am 10.05.22 um 17:35 schrieb Phil Hobbs:
    jlarkin@highlandsniptechnology.com wrote:
    On Tue, 10 May 2022 10:20:56 -0400, Phil Hobbs
    <pcdhSpamMeSenseless@electrooptical.net> wrote:

    Hi, all,

    A couple of years ago the last mainstream maker (NXP) stopped
    making the last fast PNP--the 5-GHz BFT92--thus depriving some of
    us of valuable design space, e.g. for improving the
    transconductance of FET bootstraps by wrapping a much faster PNP
    around it.

    A BF862 or CPH3910 with a BFT92 wraparound makes a 750-MHz FET with
    10x the transconductance but about the same noise.  Magic.

    I have ~9k BFT92s in stock, so I'm set for anything I might want to
    do myself, but for customer designs it's more of a worry.  Not too
    long ago, the NTE2403 was announced, but stock seems to be, *ahem*,
    thin.

    I ran across this datasheet:
    <http://www.unisonic.com.tw/datasheet/2SA1977.pdf>, which is
    marked "preliminary" and dated 2021.  It's apparently a closeish
    second source for the long lost Renesas/NEC 2SA1977, which was even
    faster than the BFT92 (8 GHz f_T).

    Anybody know anything about this outfit?  I've never heard of
    them.

    I think Renesas is the sum of NEC semi, Hitachi, Harris, Intersil.

    There is still the HFA3096, a transistor array, Si on isolator.
    Some members of this family have 5.5 GHz PNPs, still active.
    It was easy to get them space qualified a few years ago
    for a dual slope time stretcher. In a ceramic flatpack where
    nobody dared to shorten the extra long leads.  :-)

    Yeah, the package parasitics and especially the R_ee' are pretty
    disappointing. I looked at them carefully for laser noise canceller
    use, but they weren't much use. A pity.

    < https://www.digikey.de/de/products/filter/transistoren-bipolar-bjt-hf/283?s=N4IgTCBcDaIBYDMCGBmADATgGwgLoF8g


    Here too:

    https://www.digikey.com/en/products/detail/renesas-electronics-america-inc/2SA1977-T1B-A/11550285



    Yeah, there are a fair amount of NOS Renesas ones out there, apparently.
      For licensed designs it would be more comforting to be able to point to >> current production.

    I've had to redesign a few products that used fast pnp's in SOT-89.

    I have a reel of BFG31s too. (That's only a thousand pieces, of
    course.)

    #me too. Ask me if you are desperate. I don't need production quantities.

    Is quantitties a word? It should be. Sugestive as hell.   :-)

    cheers, Gerhard

    You need to get out more. ;)

    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

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    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From John Larkin@21:1/5 to pcdhSpamMeSenseless@electrooptical. on Tue May 10 09:58:06 2022
    On Tue, 10 May 2022 11:40:07 -0400, Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:

    jlarkin@highlandsniptechnology.com wrote:
    On Tue, 10 May 2022 10:20:56 -0400, Phil Hobbs
    <pcdhSpamMeSenseless@electrooptical.net> wrote:

    Hi, all,

    A couple of years ago the last mainstream maker (NXP) stopped making the >>> last fast PNP--the 5-GHz BFT92--thus depriving some of us of valuable
    design space, e.g. for improving the transconductance of FET bootstraps
    by wrapping a much faster PNP around it.

    A BF862 or CPH3910 with a BFT92 wraparound makes a 750-MHz FET with 10x
    the transconductance but about the same noise. Magic.

    I have ~9k BFT92s in stock, so I'm set for anything I might want to do
    myself, but for customer designs it's more of a worry. Not too long
    ago, the NTE2403 was announced, but stock seems to be, *ahem*, thin.

    I ran across this datasheet:
    <http://www.unisonic.com.tw/datasheet/2SA1977.pdf>, which is marked
    "preliminary" and dated 2021. It's apparently a closeish second source
    for the long lost Renesas/NEC 2SA1977, which was even faster than the
    BFT92 (8 GHz f_T).

    Anybody know anything about this outfit? I've never heard of them.

    Thanks

    Phil Hobbs

    Here's the output stage of our P400 pulse/delay generator, the one you
    have.

    https://www.dropbox.com/s/gj5252vstfiw9gw/P400_Output_A.pdf?dl=0

    It's packed with obsolete parts. I replaced it with the GaN fet
    mouse-bite thing for the next generation.

    Nice gizmo, though.

    Cheers

    Phil Hobbs

    Everybody should have one.

    --

    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

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  • From piglet@21:1/5 to Phil Hobbs on Tue May 10 19:37:41 2022
    On 10/05/2022 3:20 pm, Phil Hobbs wrote:
    Hi, all,

    A couple of years ago the last mainstream maker (NXP) stopped making the
    last fast PNP--the 5-GHz BFT92--thus depriving some of us of valuable
    design space, e.g. for improving the transconductance of FET bootstraps
    by wrapping a much faster PNP around it.

    A BF862 or CPH3910 with a BFT92 wraparound makes a 750-MHz FET with 10x
    the transconductance but about the same noise.  Magic.

    I have ~9k BFT92s in stock, so I'm set for anything I might want to do myself, but for customer designs it's more of a worry.  Not too long
    ago, the NTE2403 was announced, but stock seems to be, *ahem*, thin.

    I ran across this datasheet: <http://www.unisonic.com.tw/datasheet/2SA1977.pdf>, which is marked "preliminary" and dated 2021.  It's apparently a closeish second source
    for the long lost Renesas/NEC 2SA1977, which was even faster than the
    BFT92 (8 GHz f_T).

    Anybody know anything about this outfit?  I've never heard of them.

    Thanks

    Phil Hobbs


    Well I have heard of Unisonic and seen their parts in other gear but
    have no direct experience.

    There is still the 2SA1669 at 3GHz?

    piglet

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  • From Phil Hobbs@21:1/5 to piglet on Tue May 10 14:45:04 2022
    piglet wrote:
    On 10/05/2022 3:20 pm, Phil Hobbs wrote:
    Hi, all,

    A couple of years ago the last mainstream maker (NXP) stopped making
    the last fast PNP--the 5-GHz BFT92--thus depriving some of us of
    valuable design space, e.g. for improving the transconductance of FET
    bootstraps by wrapping a much faster PNP around it.

    A BF862 or CPH3910 with a BFT92 wraparound makes a 750-MHz FET with
    10x the transconductance but about the same noise.  Magic.

    I have ~9k BFT92s in stock, so I'm set for anything I might want to do
    myself, but for customer designs it's more of a worry.  Not too long
    ago, the NTE2403 was announced, but stock seems to be, *ahem*, thin.

    I ran across this datasheet:
    <http://www.unisonic.com.tw/datasheet/2SA1977.pdf>, which is marked
    "preliminary" and dated 2021.  It's apparently a closeish second
    source for the long lost Renesas/NEC 2SA1977, which was even faster
    than the BFT92 (8 GHz f_T).

    Anybody know anything about this outfit?  I've never heard of them.



    Well I have heard of Unisonic and seen their parts in other gear but
    have no direct experience.

    There is still the 2SA1669 at 3GHz?

    Just from brokers--no current production.

    As I say, I have three reels of BFT92s, from which I can probably build
    $10M worth of TIAs if need be. (Just ask!) ;)

    The issue is licensed designs, for which customers naturally ask
    questions about long term parts availability.

    Maybe Unisonic will come through where NTE apparently whiffed.

    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

    --- SoupGate-Win32 v1.05
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