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  • MEMS relays are back!

    From John Larkin@21:1/5 to All on Tue May 10 16:10:05 2022
    https://menlomicro.com/

    --

    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 John Walliker@21:1/5 to John Larkin on Wed May 11 02:01:31 2022
    On Wednesday, 11 May 2022 at 00:10:19 UTC+1, John Larkin wrote:
    https://menlomicro.com/

    I looked at the data for the MM1200 – 6 Channel SPST Micro Relay
    There do seem to be a lot of restrictions relating to hot switching and floating nodes. The description "ideal switch" is perhaps going a bit far. John

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  • From Ricky@21:1/5 to John Walliker on Wed May 11 06:59:35 2022
    On Wednesday, May 11, 2022 at 5:01:36 AM UTC-4, John Walliker wrote:
    On Wednesday, 11 May 2022 at 00:10:19 UTC+1, John Larkin wrote:
    https://menlomicro.com/

    I looked at the data for the MM1200 – 6 Channel SPST Micro Relay
    There do seem to be a lot of restrictions relating to hot switching and floating nodes. The description "ideal switch" is perhaps going a bit far.

    One issue I would be concerned about is the fact that it actually consists of many relays connected in parallel. When they are opened, they can not be opened simultaneously, but rather open sequentially, even if very close together in time. This would
    tend to concentrate the current flowing until the last relay contact is opened, with all the current flowing through that one contact. I suppose this is limited by parasitic inductance and the consistency in timing of the contacts opening. If they all
    open at the same time to within a nanosecond, then I don't see much problem.

    I suppose this issue is reflected in the life rating which is pretty good, at 3 billion operations, so not really a problem.

    --

    Rick C.

    - Get 1,000 miles of free Supercharging
    - Tesla referral code - https://ts.la/richard11209

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  • From Piotr Wyderski@21:1/5 to John Larkin on Wed May 11 20:49:50 2022
    John Larkin wrote:

    https://menlomicro.com/

    I would find a lot of applications for those operating in the sub-mA/3V
    range. Purchasable or "I had a dream" Silicon Valley startup vapourware?

    Best regards, Piotr

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  • From John Larkin@21:1/5 to bombald@protonmail.com on Wed May 11 12:07:28 2022
    On Wed, 11 May 2022 20:49:50 +0200, Piotr Wyderski
    <bombald@protonmail.com> wrote:

    John Larkin wrote:

    https://menlomicro.com/

    I would find a lot of applications for those operating in the sub-mA/3V >range. Purchasable or "I had a dream" Silicon Valley startup vapourware?

    Best regards, Piotr


    A lot of MEMS relay companies have arrived with great expectations and
    then quietly died. I'll wait for Digikey to have parts, and try some.

    MEMS seem OK for resonators and accelerometers, but contacts seem to
    have welding/sticking issues.

    Here's another one:

    https://atomica.com/

    Seems like they could make interesting filters, like the old Collins
    mechanical filters.

    --

    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

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Piotr Wyderski@21:1/5 to John Larkin on Wed May 11 21:16:56 2022
    John Larkin wrote:

    A lot of MEMS relay companies have arrived with great expectations and
    then quietly died. I'll wait for Digikey to have parts, and try some.

    So will I. One remark about the 6 SPST BGA: they require +79V external
    supply. Without reading the datasheet, I guess it is an electrostatic
    relay, not magnetic. Quite interesting, but wait... they can make a MEMS
    relay and fail to make a built-in charge pump?

    Best regards, Piotr

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  • From Phil Hobbs@21:1/5 to John Walliker on Wed May 11 16:53:59 2022
    John Walliker wrote:
    On Wednesday, 11 May 2022 at 00:10:19 UTC+1, John Larkin wrote:
    https://menlomicro.com/

    I looked at the data for the MM1200 – 6 Channel SPST Micro Relay
    There do seem to be a lot of restrictions relating to hot switching and floating nodes. The description "ideal switch" is perhaps going a bit far. John


    That website smells of dotcom.

    The main issues with MEMS switches are materials (good materials for
    MEMS fabrication generally aren't great electrically and mechanically)
    and the tendency of the contacts to weld or vaporize under fairly mild
    abuse, because they don't have a lot of mass to take the heat.

    If the Menlo folks have figured out how to fix those things, I'm all for it.

    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 Chris Jones@21:1/5 to Ricky on Thu May 12 22:17:03 2022
    On 11/05/2022 23:59, Ricky wrote:
    On Wednesday, May 11, 2022 at 5:01:36 AM UTC-4, John Walliker wrote:
    On Wednesday, 11 May 2022 at 00:10:19 UTC+1, John Larkin wrote:
    https://menlomicro.com/

    I looked at the data for the MM1200 – 6 Channel SPST Micro Relay
    There do seem to be a lot of restrictions relating to hot switching and
    floating nodes. The description "ideal switch" is perhaps going a bit far.

    One issue I would be concerned about is the fact that it actually consists of many relays connected in parallel. When they are opened, they can not be opened simultaneously, but rather open sequentially, even if very close together in time. This
    would tend to concentrate the current flowing until the last relay contact is opened, with all the current flowing through that one contact. I suppose this is limited by parasitic inductance and the consistency in timing of the contacts opening. If
    they all open at the same time to within a nanosecond, then I don't see much problem.

    Did you miss the part about where you have to turn off the current
    through the contacts before you are allowed to switch the MEMS relay? In
    their power relay they use a parallel MOSFET to do this. Given that the
    MEMS relay has not that great on-resistance, you could probably leave
    that bit out, and just use the MOSFET. In the RF relay, there is no
    MOSFET so you have to turn off the RF power yourself, e.g. set
    modulation of the signal such that the carrier goes away, then you can
    switch it.

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    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Chris Jones@21:1/5 to Piotr Wyderski on Thu May 12 22:21:45 2022
    On 12/05/2022 05:16, Piotr Wyderski wrote:
    John Larkin wrote:

    A lot of MEMS relay companies have arrived with great expectations and
    then quietly died. I'll wait for Digikey to have parts, and try some.

    So will I. One remark about the 6 SPST BGA: they require +79V external supply.

    Amusingly, 79V, not 77V and not 81V. Perhaps they only test it at one
    voltage and so don't know whether the parts work at other voltages.

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  • From jlarkin@highlandsniptechnology.com@21:1/5 to lugnut808@spam.yahoo.com on Thu May 12 06:54:42 2022
    On Thu, 12 May 2022 22:21:45 +1000, Chris Jones
    <lugnut808@spam.yahoo.com> wrote:

    On 12/05/2022 05:16, Piotr Wyderski wrote:
    John Larkin wrote:

    A lot of MEMS relay companies have arrived with great expectations and
    then quietly died. I'll wait for Digikey to have parts, and try some.

    So will I. One remark about the 6 SPST BGA: they require +79V external
    supply.

    Amusingly, 79V, not 77V and not 81V. Perhaps they only test it at one
    voltage and so don't know whether the parts work at other voltages.


    Or worse, maybe it really cares.



    --

    Anybody can count to one.

    - Robert Widlar

    --- SoupGate-Win32 v1.05
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  • From Piotr Wyderski@21:1/5 to jlarkin@highlandsniptechnology.com on Fri May 13 10:40:14 2022
    jlarkin@highlandsniptechnology.com wrote:

    Amusingly, 79V, not 77V and not 81V. Perhaps they only test it at one
    voltage and so don't know whether the parts work at other voltages.


    Or worse, maybe it really cares.

    It likely does:

    https://menlomicro.com/images/general/Menlo_MM1200_Preliminary_Datasheet_Rev1.2.pdf

    78V min, 80V max. This accuracy requirement calls for a built-in boost converter even stronger. It is not exactly trivial (in terms of part
    count and board space) to provide such a power rail.

    Best regards, Piotr

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  • From jlarkin@highlandsniptechnology.com@21:1/5 to bombald@protonmail.com on Fri May 13 09:36:27 2022
    On Fri, 13 May 2022 10:40:14 +0200, Piotr Wyderski
    <bombald@protonmail.com> wrote:

    jlarkin@highlandsniptechnology.com wrote:

    Amusingly, 79V, not 77V and not 81V. Perhaps they only test it at one
    voltage and so don't know whether the parts work at other voltages.


    Or worse, maybe it really cares.

    It likely does:

    https://menlomicro.com/images/general/Menlo_MM1200_Preliminary_Datasheet_Rev1.2.pdf

    78V min, 80V max. This accuracy requirement calls for a built-in boost >converter even stronger. It is not exactly trivial (in terms of part
    count and board space) to provide such a power rail.

    Best regards, Piotr

    That tolerance makes the gadget sound really flakey. As mems relays
    have historically been.





    --

    Anybody can count to one.

    - Robert Widlar

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  • From Piotr Wyderski@21:1/5 to jlarkin@highlandsniptechnology.com on Wed May 18 23:24:06 2022
    jlarkin@highlandsniptechnology.com wrote:

    That tolerance makes the gadget sound really flakey. As mems relays
    have historically been.

    This one appears to exist:

    https://www.analog.com/media/en/technical-documentation/data-sheets/adgm1304.pdf

    And it has the charge pump. But just 7.2 years of continuous on lifetime?!

    Best regards, Piotr

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  • From John Larkin@21:1/5 to bombald@protonmail.com on Wed May 18 15:40:42 2022
    On Wed, 18 May 2022 23:24:06 +0200, Piotr Wyderski
    <bombald@protonmail.com> wrote:

    jlarkin@highlandsniptechnology.com wrote:

    That tolerance makes the gadget sound really flakey. As mems relays
    have historically been.

    This one appears to exist:

    https://www.analog.com/media/en/technical-documentation/data-sheets/adgm1304.pdf

    And it has the charge pump. But just 7.2 years of continuous on lifetime?!

    Best regards, Piotr

    What a horrible part!

    --

    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

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)