ISO/IEC 15693, is an ISO/IEC standard for vicinity cards, i.e. cards which can be read from a greater distance as compared with proximity cards. Such cards can normally be read out by a reader without being powered themselves, as the reader will supply the necessary power to the card over the air (wireless). ISO/IEC 15693 systems operate at the 13.56 MHz frequency, and offer maximum read distance of 1–1.5 meters. As the vicinity cards have to operate at a greater distance, the necessary magnetic field is less (0.15 to 5 A/m) than that for a proximity card (1.5 to 7.5 A/m).

Example applications

Communication to the card

Communication from the reader to the card uses an amplitude-shift keying with 10% or 100% modulation index. The data coding is:

Communication to the reader

The card has two ways to send its data back to the reader. Both use a subcarrier transmitted back to the reader using load modulation.

Amplitude-shift keying

Amplitude-shift keying 100% modulation index on a 423.75 kHz subcarrier. The data rate can be: A logic 0 starts with eight pulses of 423.75 kHz followed by an unmodulated time of 18.88 μs (256/ fc); a logic 1 is the other way round. The data frame delimiters are code violations, a start of frame is: and the end of a frame is: The data are sent using a Manchester code.

Frequency-shift keying

Frequency-shift keying by switching between a 423.75 kHz sub carrier (operating frequency divided by 32) and a 484.25 kHz sub carrier (operating frequency divided by 28). The data rate can be: A logic 0 starts with eight pulses of 423.75 kHz followed by nine pulses of 484.28 kHz; a logic 1 is the other way round. The data frame delimiters are code violations, a start of frame is: and the end of a frame is: The data are sent using a Manchester code.

Manufacturer codes

see ISO/IEC 7816-6

Implementations

The first byte of the UID should always be 0xE0.

Products with ISO/IEC 15693 interface