Design is not all. There is a reason IC design houses are vanishing, it is too expensive to design custom chips. Only large companies can afford the tapeouts, testing, Packaging, and large volume production.
Any idea what parts are too expensive, and why? One would think that over time tapeout would have more and more processes automated, as with some testing. Packaging could be made standardize as much as possible. Thanks.
Purely analog circuits, including those with digital functions as an ancillary feature, are never on the latest process node. Analog functions don’t scale down well, high drive currents or voltage support require minimum feature sizes. The notable increase per node in terms of frequency support would be wasted even on parts operating up to the gigahertz range. Even the most aggressive analog circuits, like current RF-CMOS designs, are only released when the node is a few generations old. The process control required to get them functional within usable tolerances for analog circuits like current mirrors and differential pairs is greater than what digital designs demand
My experience is that ASICs are used for a variety of scenarios, such as consolidating components used in circuit design. Current limiters for LEDs or signal processing are two examples. They are also useful for replacing processes that were previously done in software or on FPGAs in such a way that they perform with more efficiency. None of these scenarios necessitate performance, and the latest node size. Hell in the open source community an open architecture without proprietary device drivers(blob free) is often quite desirable.