[sdiy] Can google's free* 180nm OSHW foundry be used for synth parts?

[cheater cheater]

Hey Mike, thanks for the email.
"and noise figures in single dBs, not single dBs down from the voltage
rail" - hmm, mistake perhaps?
"high voltage 50V transistors" - why is that necessary? Most synth
chips are more like 15V rail chips, I don't think I've seen synth
chips that run off 50V rails, what am I missing here?

A friend who works at a semiconductor fab told me that the process
might not support bipolar transistors (he just doesn't know if it
does), but I'm not sure how necessary those are for the purpose of
creating audio chips?

Peter,
I'm sure once people have 64 OTAs on a chip they'll find a use for them :)

Best regards


On Fri, Aug 5, 2022 at 8:36 PM Mike Bryant <mbryant at futurehorizons.com> wrote:
>
> It's a digital process with components optimised for digital 'analoguey' applications such as line drivers.  Analogue to the quality levels you are talking about need dielectric isolation, high voltage 50V transistors and much higher gains so you can apply some feedback to get distortion down, and noise figures in single dBs, not single dBs down from the voltage rail.
>
> I think it's also compulsory to include their microprocessor core on the die - it definitely was on early runs
>
>
> -----Original Message-----
> From: Synth-diy [mailto:synth-diy-bounces at synth-diy.org] On Behalf Of cheater cheater via Synth-diy
> Sent: 05 August 2022 19:16
> To: synth-diy
> Subject: [sdiy] Can google's free* 180nm OSHW foundry be used for synth parts?
>
> Google are running a program where if you submit open source chip designs they'll produce them either cheaply or for free on a 180 nm process.
>
> "We sponsored six shuttle runs over the course of two years, allowing the open source community to submit more than 350 unique designs of which around 240 were manufactured at no-cost."
>
> Is this a process that could be used for analog synth parts? We could use new OTA chips, and I think I wouldn't mind a chip with 64 monolithic OTAs on it, or chips with full voices, etc. With this feature size, leaps and bounds beyond the last time synth chips were being miniaturized, we could go wild with designs.
>
> Apparently they already have solutions for on-chip passives, single transistors, and relatively "high" voltages (10V), so the next question is how they would handle something like an OTA, VCA, op amp, etc, since most users seem to be focusing on digital chips.
>
> "The GF 180nm technology platform offers open source silicon designers new capabilities for high volume production, affordability, and more voltage options. This PDK includes the following standard cells:
> - Digital standard cells libraries (7-track and 9-track)
> - Low (3.3V), Medium (5V, 6V) and High (10V) voltage devices
> - SRAM macros (64x8, 128x8, 256x8, 512x8)
> - I/O and primitives (Resistors, Capacitors, Transistors, eFuses) cells libraries"
>
>
> https://www.phoronix.com/news/Google-GloFo-GF180MCU
>
> https://opensource.googleblog.com/2022/08/GlobalFoundries-joins-Googles-open-source-silicon-initiative.html
>
>
> If we can figure out how to take advantage of that, synth chips could become very interesting.
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