Josh Wyatt,
Do you know the answer to this question? I also sent scope plots directly to Colin Callaghan at TI on 11/18/2012 with no answer to date. The email, scope plots and description are pasted below. Does this lab data agree with TI lab data for an initiator signal?
Regards,
Eric Hooker
What is the sensitivity of the TRF7970A to a NFC-A initiator (poller) waveform directly cabled into the RX/TX 50 ohm match point of the TRF7970A using a RF signal generator. See the two scope plots below. This RX sensitivity test is not specified on the TRF7970A data sheet page 12. RX sensitivity is only specified for sub-carrier modulation where the specification is 3 mVpp max for 848 kHz sub-carrier.
First scope plot setup notes (158 mVpp file)
RF Signal generator setup: NFC-A ALL REQ waveform (obtained from R&S) using R&S Vector signal generator, amplitude = 158 mVpp as measured at TRF7970A RX_IN1 pin.
Scope setup: Used R&S RTO scope with NFC-A trigger mode selected. Bottom scope trace is modulated 13.56 MHz carrier (trigger source), top scope plot is TRF7970A data output. A valid data signal is observed.
TRF7970A setup: Direct Mode 0, 450 kHz to 1.5 MHz BPF
Second scope plot setup notes (141 mVpp file)
Signal generator setup: NFC-A ALL REQ waveform (obtained from R&S) using R&S Vector signal generator, amplitude = 141 mVpp as measured at TRF7970A RX_IN1 pin.
Scope setup: Used R&S RTO scope with NFC-A trigger mode selected. Bottom scope trace is modulated 13.56 MHz carrier (trigger source), top scope plot is TRF7970A data output. A valid data signal was not observed.
TRF7970A setup: Direct Mode 0, 450 kHz to 1.5 MHz BPF
