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=Electronics Hardware Questions=


A device based on CMOS circuit draws higher current when temperature gets:
- higher?
- lower?
the higher temperature the more consumption current.
A device draws higher current when temperature gets lower. We know from VLSI basics that a current through a MOS transistor depends on 2 parameters:
Vt - threshold voltage ;
K - coefficient of electron mobility and a device geometry aspect.
Both Vt and K are temperature sensitive.
The magnitude of Vt decreases by 2mV for every 1 degree C rise in temperature. This decrease in Vt correspondingly increases drain current. However, K - decreases with temperature and its effect is a dominant one. This may sound strange, since we remember from physics that electron mobility increases with temperature. Yes, the chaotic electron mobility increases while interfering with direct current flow.