ST25DV64K datasheet(74/200 Pages) STMICROELECTRONICS

74 / 200 page

RF operations

Contactless exchanges are performed in RF mode as specified by ISO/IEC 15693 or NFC Forum Type 5.

The ST25DVxxx communicates via the 13.56 MHz carrier electromagnetic wave on which incoming data are

demodulated from the received signal amplitude modulation (ASK: amplitude shift keying). The received ASK

wave is 10% or 100% modulated with a data rate of 1.6 Kbit/s using the 1/256 pulse coding mode or a data rate of

26 Kbit/s using the 1/4 pulse coding mode.

Outgoing data are generated by the ST25DVxxx load variation using Manchester coding with one or two

subcarrier frequencies at 423 kHz and 484 kHz. Data are transferred from the ST25DVxxx at 6.6 Kbit/s in low

data rate mode and 26 Kbit/s in high data rate mode. The ST25DVxxx supports the 53 Kbit/s in high data rate

mode in one subcarrier frequency at 423 kHz.

The ST25DVxxx follows ISO/IEC 15693 or NFC Forum Type 5 recommendation for radio-frequency power and

signal interface and for anticollision and transmission protocol.

7.1

RF communication

7.1.1

Access to a ISO/IEC 15693 device

The dialog between the “RF reader” and the ST25DVxxx takes place as follows:

These operations use the RF power transfer and communication signal interface described below (see Power

transfer, Frequency and Operating field). This technique is called RTF (Reader talk first).

•

activation of the ST25DVxxx by the RF operating field of the reader,

•

transmission of a command by the reader (ST25DVxxx detects carrier amplitude modulation)

•

transmission of a response by the ST25DVxxx(ST25DVxxx modulates is load clocked at subcarrier rate)

Operating field

The ST25DVxxx operates continuously between the minimum and maximum values of the electromagnetic field H

defined in Table 253. RF characteristics. The Reader has to generate a field within these limits.

Power transfer

Power is transferred to the ST25DVxxx by radio frequency at 13.56 MHz via coupling antennas in the ST25DVxxx

and the Reader. The RF operating field of the reader is transformed on the ST25DVxxx antenna to an AC voltage

which is rectified, filtered and internally regulated. During communications, the amplitude modulation (ASK) on

this received signal is demodulated by the ASK demodulator

Frequency

The ISO 15693 standard defines the carrier frequency (fC) of the operating field as 13.56 MHz ±7 kHz.

7.2

RF communication and energy harvesting

As the current consumption can affect the AC signal delivered by the antenna, RF communications with

ST25DVxxx are not guaranteed during voltage delivery on the energy harvesting analog output V_EH.

RF communication can disturb and possibly stop Energy Harvesting mode.

7.3

Fast transfer mode mailbox access in RF

Thanks to dedicated commands, the RF interface has the possibility to check Mailbox availability, and the

capability to access it directly to put or get a message from it (see Section 5.1 Fast transfer mode (FTM) for

specific features).

ST25DV04K ST25DV16K ST25DV64K

RF operations

DS10925 - Rev 9

page 74/200

ST25DV64K 数据表(PDF) 74 Page - STMicroelectronics

ST25DV64K 数据表(HTML) 74 Page - STMicroelectronics

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

数据表下载