Contact interface
The pad assignment and the electrical characteristics are fully compliant with ISO/IEC 7816 (part 2 and part 3). The MIFARE SAM AV2 operates with Class A and
Class B interface devices. An internal charge pump provides the EEPROM programming voltage. Note that pad C6 is not a programming voltage input but is an output line for the clock signal for I2C communication to the RC222 reader chip. Pad C8 is used as data line to the reader chip. These two pads for connection to the RC222 are the only ones deviating from the ISO standard pin assignment.

External clock frequency and bit rates
The basic operation frequency of the MIFARE SAM AV2 is 3.5712 MHz. With this frequency the following standard bit rates can be reached using ISO/IEC 7816
transmission factors F and D. The MIFARE SAM AV2 supports significantly higher transmission speeds. The maximum specified bit rate in any case is 1.5 Mbit/s.

Answer To Reset (ATR)
The MIFARE SAM AV2 offers two modes of operation identified by different ATRs. A negotiable mode where the bit rate has to be adjusted via a PPS request and a specific mode where the MIFARE SAM AV2 switches automatically to F = 128 and D = 32 (highest possible speed) after sending the ATR. Starting with the negotiable mode, the mode of operation is switched after every warm reset.
After a cold reset, the card sends the following ATR to the terminal.