ti rfid circuit
I have tried the U2270 but it does not really have good range. The problem is that it requires a sqare wave detect input. The ID2/ID12 series are much better as they are smarter and require an analogue input. The analog input is digitised and processed. Vibration and noise effects are reduced and the range is much more. With an ID2 and an external antenna I have read ISO cards at over 40cms!!! Some geeks report even more but I suspect they are driving the ID2 too hard. Another important aspect is the ID2 will accept a high Q antenna - try that on a U2270, the recommend Q is 10, give it a Q of 100 and it will stop reading completely. The see ID series are advertised at Mannings, Tectus, Adilam and a few other places. Oh yes, and the ID2 only requires an antenna and 5v. The ID12 has a biult in antenna. Makes life easy.