Hi, are you talking about low power card detection or communication?Putting metallic objects in close proximity to the antenna will cause losses, which affect both operation modes.You could also take a look at more advanced products like the ST25R391...
Hi, The chip is biasing the input signal (sinus) coming from the antenna using AGD voltage.It means that the sinus is DC biased by ~1.5V. Therefore the Antenna needs to be DC de-coupled from the antenna.All the internal filters are designed in a way ...
Hi sshafer, During production we ensure/test that several parameters are within specification and guarantee device operation as specified in the datasheet. Unfortunately the imaginary part of the driver impedance is not part of those production tests...
Hello Luigi, could you share the part of the layout related to the NFC IC? Especially related to VSP_RF and VDD decoupling and supply filtering.Another question is, how the device performs without the tag being placed on the antenna. Do you still see...
Hello Luigi, Getting one step back, I try to summarize:Initially you wanted to reduce the output power of the ST25R3911B. Measuring the field strength with a SA you have seen that the higher harmonics are quite high.The explanation for this is, that ...