Maker Pro
Maker Pro

Minimum Inductance for NFC

mikebounds

Jan 25, 2017
8
Joined
Jan 25, 2017
Messages
8
I can find recommended inductance for NFC which seems to be 4.7uH which I guess will provide communication up to 5cm with maximum power and maximum data speed, but I cannot find minimum Inductance for NFC for:
  1. Smaller distances, like actual contact to a few mm
  2. Less power requirements (i.e not using NFC for charging)
  3. Lower data speeds (i.e only transmitting a small amount of data or where slow speed is acceptable)
Does anyone know ranges of inductances that work for NFC and how this affects its use (data speed, charging rate). I found a small tag at https://www.adafruit.com/product/2800 which is only 15x6mm and from my calculations I reckon this is about 0.4uH so 10 times less than the recommended inductance and this tag does say:
Note that since the antenna is so small you'll need to put the tag right up against the device that's reading it
So is having to hold this tag close to reader the only downside?
 
Top