EM4450
EM4550
Block Diagram
Modulator
Encoder
ROM
EEPROM
+V
coil2
coil1
C
r
AC/DC
converter
Voltage
Regulator
C
s
Pow er
Control
Reset
Write Enable
Clock
Extractor
Data
Extractor
Sequencer
Command
Decoder
Control
Logic
Fig. 2
System Principle
Transceiver
Data to be sent
to transponder
Modulator
Transponder
Oscillator
Antenna
Driver
Coil 1
EM4450
Data
Decoder
Filter &
Gain
Demodulator
Coil 2
Data received
from
transponder
RECEIVE M ODE
Signal on
Transponder coil
READ M ODE
Signal on
Transceiver coil
Signal on
Transceiver coil
Signal on
Transponder coil
RF Carrier
Data
RF Carrier
Data
Fig. 3
Copyright
2003, EM Microelectronic-Marin SA
2
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