AT88SC3216CRF-MVB1G Atmel, AT88SC3216CRF-MVB1G Datasheet - Page 142

• Manufacturer Part Number: AT88SC3216CRF-MVB1G
• Description: CRYPTOMEMORY 32KBIT 16ZONE MVB
• Manufacturer: Atmel
• Series: CryptoMemory®, CryptoRF®r

Specifications of AT88SC3216CRF-MVB1G

• Rf Type: Read / Write
• Frequency: 13.56MHz
• Features: ISO1444-2, 1444-3, 32-kbits
• Package / Case: MVB Module
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

P.4.
P.5.
142
Specifications for Other Antenna Sizes
The specifications in Table 114 cannot be applied directly to PICCs with larger or smaller antennas. The characteristics
in Table 112 and Table 113 are applicable to a PICC with any antenna dimensions.
Load Modulation Amplitude measurements on larger or smaller PICCs would require the design and characterization of
a new test apparatus. These measurement results would be dependent on the apparatus and cannot be extrapolated
from the existing ISO/IEC 14443 specifications.
A reasonable estimate of the Operating Magnetic Field range for a PICC can be made for any PICC antenna size as
follows: Determine the area of the PICC antenna by measuring the outside dimensions of the loop antenna. The
Magnetic Field strength operating range is inversely proportional to the PICC antenna area (use 3000 mm2 as the ID-1
antenna area). Note however that PCD magnetic field strength must be evaluated with a calibration coil similar in area
to the PICC antenna, or the measurement result will not be accurate.
Example 1
Guidelines for operation of a 6000 mm
(Hmin) is 1.5 x 0.5 = 0.75 A/m rms. The maximum Operating Magnetic Field (Hmax) is 7.5 x 0.5 = 3.75 A/m rms. This
PICC can be expected to survive exposure to a Non-Operating Magnetic Field of 10 x 0.5 = 5.0 A/m rms.
Example 2
Guidelines for operation of a 1000 mm
(Hmin) is 1.5 x 3.0 = 4.5 A/m rms. The maximum Operating Magnetic Field (Hmax) is 7.5 x 3.0 = 22.5 A/m rms. This
PICC can be expected to survive exposure to a Non-Operating Magnetic Field of 10 x 3.0 = 30.0 A/m rms.
Warning: Exposure to magnetic field strengths in excess of 30 A/m rms may be hazardous to your health.
Modulation Index
The Modulation Index of the PCD generated magnetic field is measured by placing a calibration coil or wire loop near
the PCD antenna. Connect this loop to a high impedance oscilloscope probe and measure the amplitude modulation
(ASK) waveform as shown in Figure 52. The PCD amplitude Modulation Index is defined in ISO/IEC 14443 part 2 as
the M.I. = (A - B) / (A + B). For Type B operation the PCD modulation index is required to be between 8 % and 14 %.
If the PCD modulation is insufficient then the PICC receiver will not successfully decode the transmissions. Excessive
modulation reduces the power available to the PICC and may cause it to reset.
Figure 52.
AT88SC0808/1616/3216/6416CRF, AT88RF04C
Measurement of the PCD Amplitude Modulation Index
Modulation Depth =
Modulation Index =
2
2
PICC Antenna. 3000/6000 = 0.5 The minimum Operating Magnetic Field
PICC Antenna. 3000/1000 = 3.0 The minimum Operating Magnetic Field
( A + B )
( A - B )
B
A
where:
A = Unmodulated Signal Amplitude
B = Modulated Signal Amplitude
5276C–RFID–3/09
B
A