# Electronic – Why is it so problematic to have close to zero standby power consumption

energypowerpower supply

Each electronic device consumes electric power when it is "idle" unless it has a mechanical switch. I can understand that for example a TV with a remote control needs to "be ready" to receive a command from the remote control. But even a cell phone charger consumes power when it is connected to the outlet and not connected to the phone.

For example, Nokia claims that one of its new chargers consume less that 30 milliwatts when not connected to the phone and they say it is very cool. I don't understand – the charger is a very simple device, what does it do with those 30 milliwatts?

Why can't this standby consumption me made lower when we already have microprocessors with gazillions of transistors fitting onto a plate size of fingernail? What's the fundamental problem here?

Regarding the actual 30mW figure: if instead of mW you consider the currents involved you arrive at around 300μA (30mW at 100V). This also means a resistance of \$330\,\mathrm{k\Omega}\$. It is quite difficult to work using resistances higher than and currents lower than this while still having to sense the moment when somebody plugs the actual load.