R

EM4150

EM4350

Communication from the Transceiver to the Transponder (RECEIVE MODE)

(cont.)

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 EM4150 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.

Transceiver

Coil

Transponder

Coil

"1"

"1"

"1"

"0"

"0"

"0"

16

16

Periods of RF field (Opt 32):

Bit

Period

DATA

:

Modulation induced by the Transceiver

Modulation induced by the Transponder

16

*

Minimum

: 7/4 periods (Opt64/Opt32)

16

Periods of RF field (Opt 64):

32

32

32

32

: 1 period

Fig. 23

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