4 ms·
As someone who has designed many chips, amperage absolutely matters because it is not DC, it has very rapid transients based on workloads and that, combined wit
by throwaway9870 5y ago
As someone who has designed many chips, amperage absolutely matters because it is not DC, it has very rapid transients based on workloads and that, combined with inductance, can make power delivery very difficult. Additionally, the high current requires careful design of the package and routing because of resistance and electromigration even in the DC case.
- uberswe 5y agoI think the point is that the text makes it seem like you have something consuming the same amount of power as 3 refrigerators in your pocket.
- awesomeusername 5y agoCan you comment on why is there always a drive towards lower voltage? And how this impacts design. A nieve take would have thought higher voltage would equate to less loss to heat. But then with a higher voltage I guess those transients become relatively bigger?
- throwaway9870 5y agoA large part of modern chip design is accomplishing what you are trying to do inside a given power budget. Thus, anything that lowers power is usually a huge win. Switching power in CMOS is roughly proportional to V^2 (basic textbook, real design includes a vastly larger number of issues), so lowering V is a huge win. Also, reducing the parasitic cap with a better process is a big win for a multitude of reasons. But shrinking the process generally would require the voltage to scale also because the gate oxide was getting thinner. That is not really true any more as we reach supply voltages that are so close the Von of the devices, but used to be a clear trend. High voltages are good when you want to deliver power because that is what you need (motor HP, space heater, etc.). But we don't use an IC for power, we use it to do logic, and in that case, logic is just much more efficient at low voltages.