The part is a LDO (low-dropout regulator). You can read about these here. See also the section about the quiescent current. One more thing: what made you believe that the given explanation is wrong?
> quiescent current which ensures for the internal circuitry to work properly depends on the ambient temperature.
This statement seems to get the relationship between quiescent current and the operation of internal circuitry backwards.
Quiescent current doesn’t power the internal circuitry. Quiescent current is a measure of current consumed by the internal circuitry while it’s idle.
The temperature relationship exists because the circuitry consumes more power when it hot. But there isn’t some temperature dependent magically quiescent current provider that must work correctly for the rest of circuitry to operate. Just like there isn’t a “standby power provider” inside of a TV to allow it to remain in standby. The standby power is just a measure of the power consumed while in standby.
I really do understand what LDO means, and at least a decent amount of how they work.
I still don't think it makes sense; it's not as if you have the heat the device to be hot enough to draw the quiescent current, it's the other way around. As the internal temperature rises, the efficiency of the components degrade, things start to "leak" more current and the quiescent current draw goes up.
I think it makes sense when you read it carefully. What tripped me up is that quiescent current is usually only seen as a bad thing. It not drawing enough current also seems more like a symptom than the cause.
On my first pass I was also a bit confused whether he is talking about the regulator's internal circuitry or something else: It's not obvious that LDO stands for low-dropout regulator, so at first it felt like he's misusing "quiescent current" to refer to some kind of "standby current" (comparable to an ATX power supply +5V Standby line) that the regulator has to supply to some other circuitry that then powers on the regulator to supply the rest of the device.
This statement seems to get the relationship between quiescent current and the operation of internal circuitry backwards.
Quiescent current doesn’t power the internal circuitry. Quiescent current is a measure of current consumed by the internal circuitry while it’s idle.
The temperature relationship exists because the circuitry consumes more power when it hot. But there isn’t some temperature dependent magically quiescent current provider that must work correctly for the rest of circuitry to operate. Just like there isn’t a “standby power provider” inside of a TV to allow it to remain in standby. The standby power is just a measure of the power consumed while in standby.