Readers - RFID: Fundamentals and Applications in Contactless Smart Cards and Identification - page 309

functional modules has become worth pursuing. Because of this, it is now possible to
integrate the whole analogue section of a reader onto a silicon chip, meaning that only
a few external components are required. We will briefly described the U2270B as an
example of such a reader IC.
The reader IC U2270B by TEMIC serves as a fully integrated HF interface between
a transponder and a microcontroller (Figure 11.11).
The IC contains the following modules: on-chip oscillator, driver, received signal
conditioning and an integral power supply (Figure 11.12).

Transponder / TAG Read / write base station

Carrier

Transp.
IC

Osc

enable

RF field
typ. 125 kH z

Unlock
system

MCU

U2270B

e5530
e5550
e5560

Data

NF read channel

output

9300

TK5530-PP
e5530-GT
TK5550-PP
TK5560-PP

Figure 11.11 The low-cost reader IC U2270B represents a highly integrated HF interface.
The control unit is realised in an external microprocessor (MCU) (reproduced by permission of
TEMIC Semiconductor GmbH, Heilbronn)

DVS VEXT VS VBatt

Standby

Power supply

COIL1

= 1

MS

CFE

Frequency
adjustment

COIL2

&

R F

Driver

Oscillator

DGND

Output

Amplifier

&

Input

Lowpass filter Schmitt trigger

9692

HIPASS GND OE

Figure 11.12 Block diagram of the reader IC U2270B. The transmitter arm consists of an
oscillator and driver to supply the antenna coil. The receiver arm consists of filter, amplifier and
a Schmitt trigger (reproduced by permission of TEMIC Semiconductor GmbH, Heilbronn)