MLX90109

125kHz RFID Transceiver

3901090109

Page 2 of 15

Data Sheet

Rev 008

Jun/06

Table of Contents

1 Functional diagram .................................................................................................................................... 1

2 Description................................................................................................................................................. 1

3 Maximum ratings........................................................................................................................................ 3

4 Pad definitions and descriptions ................................................................................................................. 3

5 MLX90109 Electrical Specifications............................................................................................................ 4

6 Block Diagram ........................................................................................................................................... 5

7 General Description ................................................................................................................................... 5

7.1 Loop Gain Oscillator ............................................................................................................................ 5

7.2 Peak Detector...................................................................................................................................... 5

7.3 Band-Pass Filter .................................................................................................................................. 5

7.4 Digital demodulator.............................................................................................................................. 6

7.5 Antenna voltage definition.................................................................................................................... 6

7.6 Power Down mode .............................................................................................................................. 6

7.7 Write operation .................................................................................................................................... 6

8 System design parameters......................................................................................................................... 7

8.1 Auto start-up condition......................................................................................................................... 7

8.2 Antenna current ................................................................................................................................... 7

8.3 Antenna Impedance............................................................................................................................. 8

9 Typical configuration: READ ONLY ............................................................................................................ 9

9.1 Application diagram ............................................................................................................................. 9

9.2 Absolute minimum schematic .............................................................................................................. 9

9.3 Power consumption ........................................................................................................................... 10

9.4 Noise cancellation ............................................................................................................................. 10

9.5 Integrated decoding........................................................................................................................... 10

9.6 Close coupling................................................................................................................................... 10

10 Typical configuration: READ/WRITE ON/OFF keying (FDX-B100) .......................................................... 11

10.1 Application diagram ......................................................................................................................... 11

11 Standard information regarding manufacturability of Melexis products with different soldering processes 12

12 ESD Precautions.................................................................................................................................... 12

13 FAQ....................................................................................................................................................... 13

13.1 Is it possible to make proportional modulation (depth less than 100%) with the MLX90109?............. 13

13.2 How should I read data information from a transponder up to 15cm? ............................................... 13

13.3 Is it possible to increase the output power of the MLX90109 transceiver?......................................... 13

13.4 Are there any specific coils available for the MLX90109 transceiver? ............................................... 13

13.5 What are the recommended pull-up values on DATA and CLOCK pins? .......................................... 13

14 Package Information .............................................................................................................................. 14

14.1 Plastic SO8...................................................................................................................................... 14

15 Disclaimer.............................................................................................................................................. 15