Re:What’s harder to find than microchips? The equipment that...
by userbinator on Saturday November 06, 2021 @10:53PM
(#29136115)
First, you are very likely "pad limited", the pads to connect the chip to the package are much larger than the actual active chip area.
I remember doing the maths for this a while ago, and I believe on a 22nm process you could fit an entire 486 (1.2M transistors) in the area of a single bond pad needed for the later CPUs.
Re:What’s harder to find than microchips? The equipment that...
by squarefoot on Saturday November 06, 2021 @11:30PM
(#29136312)
> If you have the tools, you'd be better off doing a guitar pedal in a very old technology.
The parent poster probably refers to BBD delay lines such as the MN3007 and similar devices, whose awful fidelity and noise characteristics made them famous and very recognizable in old music, especially from the 70s. Emulating them in digital is doable, but that requires more complex circuitry. If one could fit a BBD delay line and its clock generator, plus a LFO and a few low noise opamps on the same die, it would be possible to create delay based (echo/flanger/phaser/chorus etc.) pedals at extremely low costs.
First, you are very likely "pad limited", the pads to connect the chip to the package are much larger than the actual active chip area.
Second, newer processes are rarely better at analog-type things. Leakage is worse, noise is worse, etc. Generally, you have to add to the transistor "length" (minimum dimension) in order to get back analog performance parameters.
Third, newer processes have to run at really small power supply voltages. Old-school metal gate CMOS in 0.5um or larger was good to 18V+--really good for things like guitar pedals.
If you have the tools, you'd be better off doing a guitar pedal in a very old technology.