EM4450
EM4550
While the transceiver is sending data to the transponder, two different modulations will be observed on both coils. During
the first half of the bit period, the EM4450/4550 is switching "ON" its modulation device causing a modulation of the RF field.
This modulation can also be observed on the transceiver's coil. The transceiver sending a bit "0" will switch "OFF" the field,
causing a 100% modulation being observed on the transponder coil.
Bit Period
DATA :
"1"
"0"
"0"
"1"
"0"
"1"
Transceiver
Coil
Transponder
Coil
Periods of RF field (Opt 64):
Periods of RF field (Opt 32):
32
16
32
16
32
16
32
16
*
Modulation induced by the Transceiver
Recommended : 7/4 periods (Opt64/Opt32)
*
Minimum
: 1 period
Modulation induced by the Transponder
Opt64 is the chip option with a bit period corresponding to 64 priods of the RF field
Opt32 is the chip option with a bit period corresponding to 32 priods of the RF field
Fig. 21
12
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