3 ms·

Some years back there was talk of an atomic clock that came in a very small package (matchbox / cigarette pack size?). Iirc, saw a price indication of $1500 som

Some years back there was talk of an atomic clock that came in a very small package (matchbox / cigarette pack size?). Iirc, saw a price indication of $1500 somewhere. Something like that still around, and/or available? Any updated designs? Personally I have no need for ultra-accurate timekeeping. But hey... an atomic clock is way cooler than a Nixie clock or oven-controlled Xtal oscillator. And no... huge 2nd hand atomic clock found on eBay etc doesn't cut it. Too big /heavy / power-hungry.

philipkglass 1y ago
You're thinking of the Chip Scale Atomic Clock, first demonstrated by NIST in 2003 and commercialized in 2011: https://www.nist.gov/noac/technology/time-and-frequency/chip-scale-clocks https://www.nist.gov/noac/technology/time-and-frequency/chip... https://spectrum.ieee.org/chipscale-atomic-clock https://spectrum.ieee.org/chipscale-atomic-clock Microchip launched their latest version earlier this year: https://www.electronicspecifier.com/products/frequency-control/microchip-releases-next-gen-atomic-clock https://www.electronicspecifier.com/products/frequency-contr...
- Palomides 1y ago
  I've heard they're struggling to get good consistent perfomance on them compared to other alternatives in similar sizes
- WarOnPrivacy 1y ago
  > Microchip launched their latest version earlier this year: Spectratime's version (mRO-50) went into a $2M piece of eye-candy that mechanically syncs a watch. https://www.urwerk.com/collections/ur-chronometry/amc https://www.urwerk.com/sites/default/files/press/docs/urwerk_amc_eng.pdf
ooterness 1y ago
You're probably thinking of chip-scale atomic clocks (CSAC). There's at least two companies that make them [1][2]. [1] https://www.microchip.com/en-us/products/clock-and-timing/components/atomic-clocks/embedded-atomic-oscillators/csac https://www.microchip.com/en-us/products/clock-and-timing/co... [2] https://www.teledyne-si.com/en-us/Products-and-Services_/Pages/Teledyne-Chip-Scale-Atomic-Clock.aspx https://www.teledyne-si.com/en-us/Products-and-Services_/Pag...
- ginko 1y ago
  Any idea what one of those would cost? (and where to buy them?)
  - nullc 1y ago
    SA.45s (and the eval board) has been on mouser in the past, I'm not sure if they carry it now because mouser continually blocks me these days. It was previously around $1500. If you're interested in a small atomic clock and don't absolutely require the very low power consumption of the SA.45s and the very small package size you can get better performance, reliability, and cost in something a big larger and quite a bit higher power consumption. The CSAC improved atomic oscillators a lot more in power than size... but its timekeeping performance is so/so as far as atomic clocks go. In particular, the surplus market has a lot of telecom rubidium that can be had quite inexpensively. I'm personally a fan of the PRS-10 (which also exists in a benchtop form, the SRS725). They seem to regularly sell on ebay for about $300 with a little breakout board for power. And unlike many small rubidiums they have very good phase noise. You can sync them to GPS time using a 1pps input (though I believe on the bare modules the 1pps sync is optional so if you want to use it be sure to get one that has it).
    - RetroTechie 1y ago
      >The CSAC improved atomic oscillators a lot more in power than size... but its timekeeping performance is so/so as far as atomic clocks go. Timekeeping of atomic clocks is still waaaayy better than next-best technologies (like temp-compensated Xtal oscillators). And size/power/$ constraints matter. So CSACs for the win imho.
      - fsh 1y ago
        A $5 GPS receiver runs circles around a CSAC, so the range of useful applications is quite limited.
        nullc 1y ago
alnwlsn 1y ago
How big is big? You can still get used FE-5680A rubidiums on Ebay for a few hundred. They are about the size of a small book and need ~20 watts. Not sure how good/useful/not broken they are since I've never had one, but over the last 10 years I've seen them in a good number of hobbyist projects. Or you could just go for GPS. That's technically still atomic clocks, but in space!

philipkglass 1y ago

You're thinking of the Chip Scale Atomic Clock, first demonstrated by NIST in 2003 and commercialized in 2011: https://www.nist.gov/noac/technology/time-and-frequency/chip-scale-clocks https://www.nist.gov/noac/technology/time-and-frequency/chip... https://spectrum.ieee.org/chipscale-atomic-clock https://spectrum.ieee.org/chipscale-atomic-clock Microchip launched their latest version earlier this year: https://www.electronicspecifier.com/products/frequency-control/microchip-releases-next-gen-atomic-clock https://www.electronicspecifier.com/products/frequency-contr...

Palomides 1y ago
I've heard they're struggling to get good consistent perfomance on them compared to other alternatives in similar sizes
WarOnPrivacy 1y ago
> Microchip launched their latest version earlier this year: Spectratime's version (mRO-50) went into a $2M piece of eye-candy that mechanically syncs a watch. https://www.urwerk.com/collections/ur-chronometry/amc https://www.urwerk.com/sites/default/files/press/docs/urwerk_amc_eng.pdf

ooterness 1y ago

You're probably thinking of chip-scale atomic clocks (CSAC). There's at least two companies that make them [1][2]. [1] https://www.microchip.com/en-us/products/clock-and-timing/components/atomic-clocks/embedded-atomic-oscillators/csac https://www.microchip.com/en-us/products/clock-and-timing/co... [2] https://www.teledyne-si.com/en-us/Products-and-Services_/Pages/Teledyne-Chip-Scale-Atomic-Clock.aspx https://www.teledyne-si.com/en-us/Products-and-Services_/Pag...

ginko 1y ago
Any idea what one of those would cost? (and where to buy them?)
- nullc 1y ago
  SA.45s (and the eval board) has been on mouser in the past, I'm not sure if they carry it now because mouser continually blocks me these days. It was previously around $1500. If you're interested in a small atomic clock and don't absolutely require the very low power consumption of the SA.45s and the very small package size you can get better performance, reliability, and cost in something a big larger and quite a bit higher power consumption. The CSAC improved atomic oscillators a lot more in power than size... but its timekeeping performance is so/so as far as atomic clocks go. In particular, the surplus market has a lot of telecom rubidium that can be had quite inexpensively. I'm personally a fan of the PRS-10 (which also exists in a benchtop form, the SRS725). They seem to regularly sell on ebay for about $300 with a little breakout board for power. And unlike many small rubidiums they have very good phase noise. You can sync them to GPS time using a 1pps input (though I believe on the bare modules the 1pps sync is optional so if you want to use it be sure to get one that has it).
  - RetroTechie 1y ago
    >The CSAC improved atomic oscillators a lot more in power than size... but its timekeeping performance is so/so as far as atomic clocks go. Timekeeping of atomic clocks is still waaaayy better than next-best technologies (like temp-compensated Xtal oscillators). And size/power/$ constraints matter. So CSACs for the win imho.
    - fsh 1y ago
      A $5 GPS receiver runs circles around a CSAC, so the range of useful applications is quite limited.
      - nullc 1y ago

alnwlsn 1y ago

How big is big? You can still get used FE-5680A rubidiums on Ebay for a few hundred. They are about the size of a small book and need ~20 watts. Not sure how good/useful/not broken they are since I've never had one, but over the last 10 years I've seen them in a good number of hobbyist projects. Or you could just go for GPS. That's technically still atomic clocks, but in space!