luancao said:thx, I have been a digital guy for many years. How can I convert digital to analog?
What books or courses shall I learn?
ocarnu said:1 system level (Matlab/Simulink, VerilogA, C, etc).
2 schematic, some hand calculations, simulation, corners, temperature;
3 layout;
4 extract + simukate the extracted (corners, so on);
5a it works, you are happy;
5b it doesn't, see why, back to step 2.
Then what shall you do next?
And BTW, what's the post-layout netlist?
vale said:I'm unhappy now because simulation result of netlist extracted from layout is quite different from the design!
luancao said:thx, I have been a digital guy for many years. How can I convert digital to analog?
What books or courses shall I learn?
ocarnu said:The process has some variation. E.g. if Vth nominal is 0.5V (so called "typical value"), actually when you fabricate it might be anywhere between 0.45 and 0.55 with some distrbution. There are lots of parameters and each of them has some variation or uncertainty. Corners take the extremes, like most unfavorable case and most favorable (which is which depends on design). If you don't simulate the corners you'll have the surprise that only 50% of the chips work. That means double the price for the chip (more actually, you have to test them to find the good ones). That means you go bankrupt .
In some designs corners are not enough. You have to take more samples from the parameters space, with a monte carlo analysis. How to take these parameters to cover efficiently the whole space, without missing the important spot, it's a science in itself.