Multiplying two numbers in an analog circuit requires taking the logarithms and add those, then converting back, or some similar trick. In practice this is don

Multiplying two numbers in an analog circuit requires taking the logarithms and add those, then converting back, or some similar trick. In practice this is done using non-linear effects of transistors[1], however the exact details of those effects are individual to each transistor and is also temperature dependent. Since the multiplication circuit relies on different transistors behaving identically, compensation circuitry and trimming is required, which will never be perfect. [1]: https://www.analog.com/media/en/training-seminars/tutorials/MT-079.pdf https://www.analog.com/media/en/training-seminars/tutorials/...