Am 09.05.2016 um 23:30 schrieb Orchid Win7 v1:

> I have to admit, I have frequently wondered why this *digital* device
> has hundreds of *analog* components on it (mostly capacitors and
> inductors). I mean, I get why they're on the motherboard rather than on
> the silicon die, but why do you need them at all?

To keep the primary components (mostly transistors) firmly within the
range of operating parameters where they behave "digitally".

Most of the capacitors are there to keep the supply voltages stable. You
wouldn't believe how much noise a digital circuit feeds back into its
power supply, and you don't want that noise to feed forward into other
parts of the circuitry.

> Is there a simple relationship between circuit design and heat output? I
> mean, is it something as simple as number of switching elements and how
> fast they switch per second? Or is it something more complicated?

Power consumption (and hence heat output) of modern (i.e. FET-based)
digital electronic circuitry mainly depends on the total number of
transistors changing state every second, because that's when currents flow.

However, the relationship between per-transistor switching frequency and
power consumption is non-linear (presuming the circuitry is operated at
its limits), since higher switching frequencies require faster charge
transfers, which means shorter pulses of higher currents, which in turn
also require higher voltages to drive them.

In addition to this inevitable "payload" power consumption there will be
various parasitic losses, such as from inevitable signal line
inductivities and capacitances, as well as plain old leakage currents,
all of which obviously get worse with increased operating voltages, chip
area and complexity, but in /very/ non-linear ways.

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