Hi,
My customer is using TRF7963A with 3.3V VIN.
While they are testing, They found strange behavior of TRF7963A
With exactly same board, when they set Chip Status Control Register (0x00) as a 0x20(VIN voltage range 3-V operation) it's tag recognition range is around 4~9 cm. however, when they set this register as 0x21(VIN voltage range 5-V operation), the recognition distance is increased to 18~37cm. and there is no big difference on current consumption.
Their questions are:
1. is this normal operation?
2. if it's not normal, is it ok to set 5v operation while using 3.3V input voltage?
3. if it's not normal, how can they fix this problem?
and to decrease current consumption, what should they do with hardware?
Here is their schematic.
Best Regards,
Ted
