The transistors are the hard part to integrate here. From the manufacturing side, why waste the die space on your MCU production line when you can use a much ol

The transistors are the hard part to integrate here. From the manufacturing side, why waste the die space on your MCU production line when you can use a much older process to build transistors for pennies. For mixed signal design in general, the Cypress PSoC 4 series is pretty good. Renesas is also doing a lot of work in the low BOM cost configurable analog/digital space, with Greenpak and ForgeFPGA: https://www.renesas.com/tw/en/products/programmable-mixed-signal-asic-ip-products/forgefpga-low-density-fpgas https://www.renesas.com/tw/en/products/programmable-mixed-si... https://www.renesas.com/tw/en/products/programmable-mixed-signal-asic-ip-products/greenpak-programmable-mixed-signal-products https://www.renesas.com/tw/en/products/programmable-mixed-si...