VIN limits - are they even accurate?

Are the VIN limits specified for the Arduino remotely accurate?

I just burned out my Arduno Nano's voltage regulator by applying 11.9VDC to GND and VIN (appropriate polarity). In accordance with the Nano's documentation which reads:

Operating Voltage (logic level) 5 V Input Voltage (recommended) 7-12 V Input Voltage (limits) 6-20 V

So I assume 11.9V on VIN should be fine., but apparently not because my voltage regulator was glowing red hot.

Does anybody have any insight on this?

Are you sure you got the polarity right?

Did you have any other devices connected? Like, something that might put a heavy load on it?

That absolutely should not happen.... but most (all?) of the Nano's now available online are clones from china, of widely varying quality (that's why they're only like $3 a piece) - could be that some of the clones use particularly awful regulators or something.

You need to be careful with power supplies. It can say 12V but that could be AC or DC. Normally if AC the output voltage is at full load, it can go up a lot depending on the transformer impedance. DC can be regulated which will give you 12VDC however if it is unregulated you can get a wide voltage range and ripple voltage. If you check the power supply label then check it with an appropriate volt meter you will find your problem.

I think DrAzzy may be correct.

The power supply I am using is laboratory grade and does not achieve higher voltages when under lower loads.

Have you checked the voltage on the supplies with nothing connected to them?

Accentrix: So I assume 11.9V on VIN should be fine., but apparently not because my voltage regulator was glowing red hot.

So what else was connected? The onboard LEDs can make the regulator warm but hot...