MLX90109

125kHz RFID Transceiver

3901090109

Page 7 of 16

Data Sheet

Rev 011

Jun/12

7.4 Digital demodulator

The MODE pin defines whether the MLX90109 will issue directly the filtered data stream on the DATA pin

In these two

decoding modes, the MLX90109 issues the tag data on the DATA pin at the rising edge of the clock, which is

issued on the CLOCK pin. Both CLOCK and DATA are open drain outputs and require external pull-up

resistors.

FLOAT (*)

SPEED

4kBaud

-

2kBaud

MODE

Biphase

No decoding

Manchester

7.5 Antenna voltage definition

The MLX90109 is a reader IC working in a frequency range of 100 to 150kHz, and designed for use with a

parallel L-C antenna. This concept requires significantly less current than traditional serial antennas, for

building up the same magnetic field strength.

(1)

OS

MODU

DD

ant

V

V

V

V

+

−

=

Note: In order to use the internal driver FET as an ideal current source, the voltage on the coil pin should

7.6 Power Down mode

7.7 Write operation

A sequence of power up / power down periods sets the antenna voltage ON and OFF. This feature allows to

simply make an ON/OFF-keying modulated signal to the transponder.

Refer to the section “Typical operating configurations” further in this document for more detailed information

and practical hints.