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  • more phemts

    From john larkin@21:1/5 to All on Thu Oct 26 10:19:50 2023
    https://www.minicircuits.com/WebStore/dashboard.html?model=TAV1-541NM%2B&utm_campaign=Product%20Focus%20Emails%202023%20%26%20Onward&utm_medium=email&_hsmi=279821766&_hsenc=p2ANqtz-9MbcHJHjYg6_2uzVDHSL13EsHrk1Q6ZhSHQEwOQSif6Y1l55GNDwI_
    YEWiJGP8nVJdlmIf1bwj6kW8ZaQVj8XtIGwlLgVa4tPz5ednrtuuRQiRkNY&utm_content=279665588&utm_source=hs_email

    MiniCircuits calls these both MMICs and Transistors, but they sure
    look like bare transistors.

    The 45 MHz lower frequency limit is strange.

    THey do have DC curves, which is refreshing in an RF part.

    Rds-on, seldom specified for an RF part, looks like about 5 ohms.

    I wish they had Spice models.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Uwe Bonnes@21:1/5 to Uwe Bonnes on Thu Oct 26 20:01:53 2023
    Uwe Bonnes <bon@hertz.ikp.physik.tu-darmstadt.de> wrote:
    john larkin <jl@650pot.com> wrote:
    https://www.minicircuits.com/WebStore/dashboard.html?model=TAV1-541NM%2B&utm_campaign=Product%20Focus%20Emails%202023%20%26%20Onward&utm_medium=email&_hsmi=279821766&_hsenc=p2ANqtz-9MbcHJHjYg6_2uzVDHSL13EsHrk1Q6ZhSHQEwOQSif6Y1l55GNDwI_
    YEWiJGP8nVJdlmIf1bwj6kW8ZaQVj8XtIGwlLgVa4tPz5ednrtuuRQiRkNY&utm_content=279665588&utm_source=hs_email

    MiniCircuits calls these both MMICs and Transistors, but they sure
    look like bare transistors.

    The 45 MHz lower frequency limit is strange.

    THey do have DC curves, which is refreshing in an RF part.

    Rds-on, seldom specified for an RF part, looks like about 5 ohms.

    I wish they had Spice models.


    I do not find the DC curves in the datasheet. Can you give a hint?

    "DC curves" are tables in the "View Graphs" ...
    --
    Uwe Bonnes bon@elektron.ikp.physik.tu-darmstadt.de

    Institut fuer Kernphysik Schlossgartenstrasse 9 64289 Darmstadt
    --------- Tel. 06151 1623569 ------- Fax. 06151 1623305 ---------

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Uwe Bonnes@21:1/5 to john larkin on Thu Oct 26 19:54:19 2023
    john larkin <jl@650pot.com> wrote:
    https://www.minicircuits.com/WebStore/dashboard.html?model=TAV1-541NM%2B&utm_campaign=Product%20Focus%20Emails%202023%20%26%20Onward&utm_medium=email&_hsmi=279821766&_hsenc=p2ANqtz-9MbcHJHjYg6_2uzVDHSL13EsHrk1Q6ZhSHQEwOQSif6Y1l55GNDwI_
    YEWiJGP8nVJdlmIf1bwj6kW8ZaQVj8XtIGwlLgVa4tPz5ednrtuuRQiRkNY&utm_content=279665588&utm_source=hs_email

    MiniCircuits calls these both MMICs and Transistors, but they sure
    look like bare transistors.

    The 45 MHz lower frequency limit is strange.

    THey do have DC curves, which is refreshing in an RF part.

    Rds-on, seldom specified for an RF part, looks like about 5 ohms.

    I wish they had Spice models.


    I do not find the DC curves in the datasheet. Can you give a hint?
    --
    Uwe Bonnes bon@elektron.ikp.physik.tu-darmstadt.de

    Institut fuer Kernphysik Schlossgartenstrasse 9 64289 Darmstadt
    --------- Tel. 06151 1623569 ------- Fax. 06151 1623305 ---------

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From john larkin@21:1/5 to bon@hertz.ikp.physik.tu-darmstadt.d on Thu Oct 26 13:13:33 2023
    On 26 Oct 2023 19:54:19 GMT, Uwe Bonnes
    <bon@hertz.ikp.physik.tu-darmstadt.de> wrote:

    john larkin <jl@650pot.com> wrote:
    https://www.minicircuits.com/WebStore/dashboard.html?model=TAV1-541NM%2B&utm_campaign=Product%20Focus%20Emails%202023%20%26%20Onward&utm_medium=email&_hsmi=279821766&_hsenc=p2ANqtz-9MbcHJHjYg6_2uzVDHSL13EsHrk1Q6ZhSHQEwOQSif6Y1l55GNDwI_
    YEWiJGP8nVJdlmIf1bwj6kW8ZaQVj8XtIGwlLgVa4tPz5ednrtuuRQiRkNY&utm_content=279665588&utm_source=hs_email

    MiniCircuits calls these both MMICs and Transistors, but they sure
    look like bare transistors.

    The 45 MHz lower frequency limit is strange.

    THey do have DC curves, which is refreshing in an RF part.

    Rds-on, seldom specified for an RF part, looks like about 5 ohms.

    I wish they had Spice models.


    I do not find the DC curves in the datasheet. Can you give a hint?

    Data sheet page 3. That suggets operation down to DC.

    The 45 MHz might be caused by coupling caps on the eval board or
    something. I want to use parts like these as switches.

    Some MMICs have internal bias circuits that indeed wreck the low
    frequency response.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From john larkin@21:1/5 to All on Thu Oct 26 15:48:49 2023
    On Fri, 27 Oct 2023 01:19:18 +0300, Dimiter_Popoff <dp@tgi-sci.com>
    wrote:

    On 10/26/2023 23:13, john larkin wrote:
    On 26 Oct 2023 19:54:19 GMT, Uwe Bonnes
    <bon@hertz.ikp.physik.tu-darmstadt.de> wrote:

    john larkin <jl@650pot.com> wrote:
    https://www.minicircuits.com/WebStore/dashboard.html?model=TAV1-541NM%2B&utm_campaign=Product%20Focus%20Emails%202023%20%26%20Onward&utm_medium=email&_hsmi=279821766&_hsenc=p2ANqtz-9MbcHJHjYg6_2uzVDHSL13EsHrk1Q6ZhSHQEwOQSif6Y1l55GNDwI_
    YEWiJGP8nVJdlmIf1bwj6kW8ZaQVj8XtIGwlLgVa4tPz5ednrtuuRQiRkNY&utm_content=279665588&utm_source=hs_email

    MiniCircuits calls these both MMICs and Transistors, but they sure
    look like bare transistors.

    The 45 MHz lower frequency limit is strange.

    THey do have DC curves, which is refreshing in an RF part.

    Rds-on, seldom specified for an RF part, looks like about 5 ohms.

    I wish they had Spice models.


    I do not find the DC curves in the datasheet. Can you give a hint?

    Data sheet page 3. That suggets operation down to DC.

    The 45 MHz might be caused by coupling caps on the eval board or
    something. I want to use parts like these as switches.

    Some MMICs have internal bias circuits that indeed wreck the low
    frequency response.


    They do look interesting as switches indeed.
    Are they JFET-s? That gate-source +0.7V max and the max gate
    current suggest sort of that, although 0.7 looks too high.
    I have biased (during wrestling this or that, not in an end
    product IIRC) JFETS slightly above 0 G-S to get even less
    channel resistance but they must have brought that to a
    new level somehow.

    These are phemts, which are enhancement mode parts that turn on at a
    few tenths of a volt. Capacitances are crazy low. We use them as
    switches, typically to discharge a timing ramp capacitor or some such.

    I have taken a lot of data on their SAV541 and SAV551 parts, which
    look very similar. I can post that if anyone is interested. The SAVs
    have wire bonds inside; maybe these don't.

    I did find remarkable effects if they are driven past suggested data
    sheet limits. They just keep enhancing!

    The Supertex depletion-mode mosfets enhance some too.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Dimiter_Popoff@21:1/5 to john larkin on Fri Oct 27 01:19:18 2023
    On 10/26/2023 23:13, john larkin wrote:
    On 26 Oct 2023 19:54:19 GMT, Uwe Bonnes <bon@hertz.ikp.physik.tu-darmstadt.de> wrote:

    john larkin <jl@650pot.com> wrote:
    https://www.minicircuits.com/WebStore/dashboard.html?model=TAV1-541NM%2B&utm_campaign=Product%20Focus%20Emails%202023%20%26%20Onward&utm_medium=email&_hsmi=279821766&_hsenc=p2ANqtz-9MbcHJHjYg6_2uzVDHSL13EsHrk1Q6ZhSHQEwOQSif6Y1l55GNDwI_
    YEWiJGP8nVJdlmIf1bwj6kW8ZaQVj8XtIGwlLgVa4tPz5ednrtuuRQiRkNY&utm_content=279665588&utm_source=hs_email

    MiniCircuits calls these both MMICs and Transistors, but they sure
    look like bare transistors.

    The 45 MHz lower frequency limit is strange.

    THey do have DC curves, which is refreshing in an RF part.

    Rds-on, seldom specified for an RF part, looks like about 5 ohms.

    I wish they had Spice models.


    I do not find the DC curves in the datasheet. Can you give a hint?

    Data sheet page 3. That suggets operation down to DC.

    The 45 MHz might be caused by coupling caps on the eval board or
    something. I want to use parts like these as switches.

    Some MMICs have internal bias circuits that indeed wreck the low
    frequency response.


    They do look interesting as switches indeed.
    Are they JFET-s? That gate-source +0.7V max and the max gate
    current suggest sort of that, although 0.7 looks too high.
    I have biased (during wrestling this or that, not in an end
    product IIRC) JFETS slightly above 0 G-S to get even less
    channel resistance but they must have brought that to a
    new level somehow.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Joe Gwinn@21:1/5 to All on Thu Oct 26 18:54:38 2023
    On Fri, 27 Oct 2023 01:19:18 +0300, Dimiter_Popoff <dp@tgi-sci.com>
    wrote:

    On 10/26/2023 23:13, john larkin wrote:
    On 26 Oct 2023 19:54:19 GMT, Uwe Bonnes
    <bon@hertz.ikp.physik.tu-darmstadt.de> wrote:

    john larkin <jl@650pot.com> wrote:
    https://www.minicircuits.com/WebStore/dashboard.html?model=TAV1-541NM%2B&utm_campaign=Product%20Focus%20Emails%202023%20%26%20Onward&utm_medium=email&_hsmi=279821766&_hsenc=p2ANqtz-9MbcHJHjYg6_2uzVDHSL13EsHrk1Q6ZhSHQEwOQSif6Y1l55GNDwI_
    YEWiJGP8nVJdlmIf1bwj6kW8ZaQVj8XtIGwlLgVa4tPz5ednrtuuRQiRkNY&utm_content=279665588&utm_source=hs_email

    MiniCircuits calls these both MMICs and Transistors, but they sure
    look like bare transistors.

    The 45 MHz lower frequency limit is strange.

    THey do have DC curves, which is refreshing in an RF part.

    Rds-on, seldom specified for an RF part, looks like about 5 ohms.

    I wish they had Spice models.


    I do not find the DC curves in the datasheet. Can you give a hint?

    Data sheet page 3. That suggets operation down to DC.

    The 45 MHz might be caused by coupling caps on the eval board or
    something. I want to use parts like these as switches.

    Some MMICs have internal bias circuits that indeed wreck the low
    frequency response.


    They do look interesting as switches indeed.
    Are they JFET-s? That gate-source +0.7V max and the max gate
    current suggest sort of that, although 0.7 looks too high.
    I have biased (during wrestling this or that, not in an end
    product IIRC) JFETS slightly above 0 G-S to get even less
    channel resistance but they must have brought that to a
    new level somehow.

    They are not JFETS. MiniCircuits has a good summary.

    .<https://blog.minicircuits.com/mmic-technologies-pseudomorphic-high-electron-mobility-transistor-phemt/>

    People have observed that pHEMTs seem to have relatively low flicker
    noise for a GHz amplifier. My guess is that this is because very
    clean materials and processes are needed to make a pHEMT.

    Joe Gwinn

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Phil Hobbs@21:1/5 to john larkin on Fri Oct 27 03:06:22 2023
    john larkin <jl@650pot.com> wrote:
    On Fri, 27 Oct 2023 01:19:18 +0300, Dimiter_Popoff <dp@tgi-sci.com>
    wrote:

    On 10/26/2023 23:13, john larkin wrote:
    On 26 Oct 2023 19:54:19 GMT, Uwe Bonnes
    <bon@hertz.ikp.physik.tu-darmstadt.de> wrote:

    john larkin <jl@650pot.com> wrote:
    https://www.minicircuits.com/WebStore/dashboard.html?model=TAV1-541NM%2B&utm_campaign=Product%20Focus%20Emails%202023%20%26%20Onward&utm_medium=email&_hsmi=279821766&_hsenc=p2ANqtz-9MbcHJHjYg6_2uzVDHSL13EsHrk1Q6ZhSHQEwOQSif6Y1l55GNDwI_
    YEWiJGP8nVJdlmIf1bwj6kW8ZaQVj8XtIGwlLgVa4tPz5ednrtuuRQiRkNY&utm_content=279665588&utm_source=hs_email

    MiniCircuits calls these both MMICs and Transistors, but they sure
    look like bare transistors.

    The 45 MHz lower frequency limit is strange.

    THey do have DC curves, which is refreshing in an RF part.

    Rds-on, seldom specified for an RF part, looks like about 5 ohms.

    I wish they had Spice models.


    I do not find the DC curves in the datasheet. Can you give a hint?

    Data sheet page 3. That suggets operation down to DC.

    The 45 MHz might be caused by coupling caps on the eval board or
    something. I want to use parts like these as switches.

    Some MMICs have internal bias circuits that indeed wreck the low
    frequency response.


    They do look interesting as switches indeed.
    Are they JFET-s? That gate-source +0.7V max and the max gate
    current suggest sort of that, although 0.7 looks too high.
    I have biased (during wrestling this or that, not in an end
    product IIRC) JFETS slightly above 0 G-S to get even less
    channel resistance but they must have brought that to a
    new level somehow.

    These are phemts, which are enhancement mode parts that turn on at a
    few tenths of a volt. Capacitances are crazy low. We use them as
    switches, typically to discharge a timing ramp capacitor or some such.

    I have taken a lot of data on their SAV541 and SAV551 parts, which
    look very similar. I can post that if anyone is interested. The SAVs
    have wire bonds inside; maybe these don't.

    I did find remarkable effects if they are driven past suggested data
    sheet limits. They just keep enhancing!

    The Supertex depletion-mode mosfets enhance some too.



    Any and all measurements welcome!

    Thanks

    Phil Hobbs

    --
    Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From John Larkin@21:1/5 to pcdhSpamMeSenseless@electrooptical. on Thu Oct 26 20:27:09 2023
    On Fri, 27 Oct 2023 03:06:22 -0000 (UTC), Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:

    john larkin <jl@650pot.com> wrote:
    On Fri, 27 Oct 2023 01:19:18 +0300, Dimiter_Popoff <dp@tgi-sci.com>
    wrote:

    On 10/26/2023 23:13, john larkin wrote:
    On 26 Oct 2023 19:54:19 GMT, Uwe Bonnes
    <bon@hertz.ikp.physik.tu-darmstadt.de> wrote:

    john larkin <jl@650pot.com> wrote:
    https://www.minicircuits.com/WebStore/dashboard.html?model=TAV1-541NM%2B&utm_campaign=Product%20Focus%20Emails%202023%20%26%20Onward&utm_medium=email&_hsmi=279821766&_hsenc=p2ANqtz-9MbcHJHjYg6_2uzVDHSL13EsHrk1Q6ZhSHQEwOQSif6Y1l55GNDwI_
    YEWiJGP8nVJdlmIf1bwj6kW8ZaQVj8XtIGwlLgVa4tPz5ednrtuuRQiRkNY&utm_content=279665588&utm_source=hs_email

    MiniCircuits calls these both MMICs and Transistors, but they sure >>>>>> look like bare transistors.

    The 45 MHz lower frequency limit is strange.

    THey do have DC curves, which is refreshing in an RF part.

    Rds-on, seldom specified for an RF part, looks like about 5 ohms.

    I wish they had Spice models.


    I do not find the DC curves in the datasheet. Can you give a hint?

    Data sheet page 3. That suggets operation down to DC.

    The 45 MHz might be caused by coupling caps on the eval board or
    something. I want to use parts like these as switches.

    Some MMICs have internal bias circuits that indeed wreck the low
    frequency response.


    They do look interesting as switches indeed.
    Are they JFET-s? That gate-source +0.7V max and the max gate
    current suggest sort of that, although 0.7 looks too high.
    I have biased (during wrestling this or that, not in an end
    product IIRC) JFETS slightly above 0 G-S to get even less
    channel resistance but they must have brought that to a
    new level somehow.

    These are phemts, which are enhancement mode parts that turn on at a
    few tenths of a volt. Capacitances are crazy low. We use them as
    switches, typically to discharge a timing ramp capacitor or some such.

    I have taken a lot of data on their SAV541 and SAV551 parts, which
    look very similar. I can post that if anyone is interested. The SAVs
    have wire bonds inside; maybe these don't.

    I did find remarkable effects if they are driven past suggested data
    sheet limits. They just keep enhancing!

    The Supertex depletion-mode mosfets enhance some too.



    Any and all measurements welcome!

    Thanks

    Phil Hobbs

    Here's some random measurements.

    https://www.dropbox.com/scl/fo/944svmozmwh4cfploqhyv/h?rlkey=gjueh508twp483vq20dlkeaq1&dl=0

    In another case, I pulsed the gate positive at a low duty cycle, and
    it just kept conducting harder. I went to +1.2 volts. That is probably long-term bad news, but they sure switched hard.

    The models are based on your models, tweaked a bit per measurements.

    The xray shows the geometry and wire bonds.

    My Colpotts oscillator kept doing weird things, probably GHz
    oscillations, which was fixed with a *500 ohm* gate resisor.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From legg@21:1/5 to john larkin on Fri Oct 27 08:04:35 2023
    On Thu, 26 Oct 2023 10:19:50 -0700, john larkin <jl@650pot.com> wrote:

    https://www.minicircuits.com/WebStore/dashboard.html?model=TAV1-541NM%2B&utm_campaign=Product%20Focus%20Emails%202023%20%26%20Onward&utm_medium=email&_hsmi=279821766&_hsenc=p2ANqtz-9MbcHJHjYg6_2uzVDHSL13EsHrk1Q6ZhSHQEwOQSif6Y1l55GNDwI_
    YEWiJGP8nVJdlmIf1bwj6kW8ZaQVj8XtIGwlLgVa4tPz5ednrtuuRQiRkNY&utm_content=279665588&utm_source=hs_email

    MiniCircuits calls these both MMICs and Transistors, but they sure
    look like bare transistors.

    The 45 MHz lower frequency limit is strange.

    THey do have DC curves, which is refreshing in an RF part.

    Rds-on, seldom specified for an RF part, looks like about 5 ohms.

    I wish they had Spice models.


    Package size and pinout is roughly equivalent to HP 'minipak'
    used for HMPP-3890/92/95.

    RL

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From John Larkin@21:1/5 to legg on Fri Oct 27 05:58:00 2023
    On Fri, 27 Oct 2023 08:04:35 -0400, legg <legg@nospam.magma.ca> wrote:

    On Thu, 26 Oct 2023 10:19:50 -0700, john larkin <jl@650pot.com> wrote:

    https://www.minicircuits.com/WebStore/dashboard.html?model=TAV1-541NM%2B&utm_campaign=Product%20Focus%20Emails%202023%20%26%20Onward&utm_medium=email&_hsmi=279821766&_hsenc=p2ANqtz-9MbcHJHjYg6_2uzVDHSL13EsHrk1Q6ZhSHQEwOQSif6Y1l55GNDwI_
    YEWiJGP8nVJdlmIf1bwj6kW8ZaQVj8XtIGwlLgVa4tPz5ednrtuuRQiRkNY&utm_content=279665588&utm_source=hs_email

    MiniCircuits calls these both MMICs and Transistors, but they sure
    look like bare transistors.

    The 45 MHz lower frequency limit is strange.

    THey do have DC curves, which is refreshing in an RF part.

    Rds-on, seldom specified for an RF part, looks like about 5 ohms.

    I wish they had Spice models.


    Package size and pinout is roughly equivalent to HP 'minipak'
    used for HMPP-3890/92/95.

    RL

    PIN diodes. Interestingly also specified to 6 GHz max. The phemt has a
    funny round 5th pin of unknown function.

    I've tried using PIN diodes in time domain with expensively bad
    results. Some RF parts are usable in time domain, some aren't. The RF
    boys just ignore that market.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Phil Hobbs@21:1/5 to john larkin on Sun Oct 29 09:19:28 2023
    On 2023-10-26 13:19, john larkin wrote:
    https://www.minicircuits.com/WebStore/dashboard.html?model=TAV1-541NM%2B&utm_campaign=Product%20Focus%20Emails%202023%20%26%20Onward&utm_medium=email&_hsmi=279821766&_hsenc=p2ANqtz-9MbcHJHjYg6_2uzVDHSL13EsHrk1Q6ZhSHQEwOQSif6Y1l55GNDwI_
    YEWiJGP8nVJdlmIf1bwj6kW8ZaQVj8XtIGwlLgVa4tPz5ednrtuuRQiRkNY&utm_content=279665588&utm_source=hs_email

    MiniCircuits calls these both MMICs and Transistors, but they sure
    look like bare transistors.

    The 45 MHz lower frequency limit is strange.

    THey do have DC curves, which is refreshing in an RF part.

    Rds-on, seldom specified for an RF part, looks like about 5 ohms.

    I wish they had Spice models.


    Those are the same as the SAV series, but in a different package. The
    $70 sample kit has both kinds.

    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
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Phil Hobbs@21:1/5 to Joe Gwinn on Sun Oct 29 09:32:01 2023
    On 2023-10-26 18:54, Joe Gwinn wrote:
    On Fri, 27 Oct 2023 01:19:18 +0300, Dimiter_Popoff <dp@tgi-sci.com>
    wrote:

    On 10/26/2023 23:13, john larkin wrote:
    On 26 Oct 2023 19:54:19 GMT, Uwe Bonnes
    <bon@hertz.ikp.physik.tu-darmstadt.de> wrote:

    john larkin <jl@650pot.com> wrote:
    https://www.minicircuits.com/WebStore/dashboard.html?model=TAV1-541NM%2B&utm_campaign=Product%20Focus%20Emails%202023%20%26%20Onward&utm_medium=email&_hsmi=279821766&_hsenc=p2ANqtz-9MbcHJHjYg6_2uzVDHSL13EsHrk1Q6ZhSHQEwOQSif6Y1l55GNDwI_
    YEWiJGP8nVJdlmIf1bwj6kW8ZaQVj8XtIGwlLgVa4tPz5ednrtuuRQiRkNY&utm_content=279665588&utm_source=hs_email

    MiniCircuits calls these both MMICs and Transistors, but they sure
    look like bare transistors.

    The 45 MHz lower frequency limit is strange.

    THey do have DC curves, which is refreshing in an RF part.

    Rds-on, seldom specified for an RF part, looks like about 5 ohms.

    I wish they had Spice models.


    I do not find the DC curves in the datasheet. Can you give a hint?

    Data sheet page 3. That suggets operation down to DC.

    The 45 MHz might be caused by coupling caps on the eval board or
    something. I want to use parts like these as switches.

    Some MMICs have internal bias circuits that indeed wreck the low
    frequency response.


    They do look interesting as switches indeed.
    Are they JFET-s? That gate-source +0.7V max and the max gate
    current suggest sort of that, although 0.7 looks too high.
    I have biased (during wrestling this or that, not in an end
    product IIRC) JFETS slightly above 0 G-S to get even less
    channel resistance but they must have brought that to a
    new level somehow.

    They are not JFETS. MiniCircuits has a good summary.

    .<https://blog.minicircuits.com/mmic-technologies-pseudomorphic-high-electron-mobility-transistor-phemt/>

    People have observed that pHEMTs seem to have relatively low flicker
    noise for a GHz amplifier. My guess is that this is because very
    clean materials and processes are needed to make a pHEMT.

    Joe Gwinn


    The ones I've measured have 1/f corners of 10-50 MHz. With a flatband
    noise of 0.3 nV in 1 Hz, that gets you about 1-nV noise at 1 MHz, not
    awful at all.

    They're great for bootstraps, as long as you bootstrap their drains as well--otherwise they make very disappointing followers.

    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 John Larkin@21:1/5 to pcdhSpamMeSenseless@electrooptical. on Sun Oct 29 10:44:44 2023
    On Sun, 29 Oct 2023 09:19:28 -0400, Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:

    On 2023-10-26 13:19, john larkin wrote:
    https://www.minicircuits.com/WebStore/dashboard.html?model=TAV1-541NM%2B&utm_campaign=Product%20Focus%20Emails%202023%20%26%20Onward&utm_medium=email&_hsmi=279821766&_hsenc=p2ANqtz-9MbcHJHjYg6_2uzVDHSL13EsHrk1Q6ZhSHQEwOQSif6Y1l55GNDwI_
    YEWiJGP8nVJdlmIf1bwj6kW8ZaQVj8XtIGwlLgVa4tPz5ednrtuuRQiRkNY&utm_content=279665588&utm_source=hs_email

    MiniCircuits calls these both MMICs and Transistors, but they sure
    look like bare transistors.

    The 45 MHz lower frequency limit is strange.

    THey do have DC curves, which is refreshing in an RF part.

    Rds-on, seldom specified for an RF part, looks like about 5 ohms.

    I wish they had Spice models.


    Those are the same as the SAV series, but in a different package. The
    $70 sample kit has both kinds.

    Cheers

    Phil Hobbs

    Good news. It sounds like these parts are popular enough to add new
    packages, which suggests they may be available for a while. Several
    other sources of phemts have discontinued them.

    Less inductance is good.

    https://www.dropbox.com/s/qttp09vpw3kcee3/SAV541_Xray.jpg?raw=1

    We have a new xray machine that can resolve wirebonds. I'll get some
    pics of the new versions, the entire sample kit.

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  • From Gerhard Hoffmann@21:1/5 to All on Mon Nov 13 01:39:10 2023
    Am 27.10.23 um 14:58 schrieb John Larkin:

    PIN diodes. Interestingly also specified to 6 GHz max. The phemt has a
    funny round 5th pin of unknown function.

    Probably they have the old standard 8753A VNA.

    The 8720C started at ~50 MHz, for the Mini circuits thread above.

    cheers, Gerhard

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