EM4450
EM4550
Block Diagram
ROM
Modulator
Encoder
EEPROM
+V
Voltage
Regulator
coil2
AC/DC
converter
C
Cs
Pow er
Control
r
coil1
Reset
Write Enable
Clock
Control
Logic
Sequencer
Ex tractor
Data
Command
Decoder
Ex tractor
Fig. 2
System Principle
Transceiver
Transponder
Data to be sent
to transponder
Modulator
Coil 1
Antenna
Driver
Oscillator
EM4450
Data
Filter &
Demodulator
Coil 2
Decoder
Gain
Data received
from
transponder
RECEIVE MODE
READ MODE
Signal on
Transponder coil
Signal on
Transceiver coil
Signal on
Transceiver coil
Signal on
Transponder coil
RF Carrier
Data
RF Carrier
Data
Fig. 3
2
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