MLX90620

16x4 IR array

3001090620

Page 3 of 40

Datasheet IR16x4

Rev 4.0

19 September 2012

1 Table of contents

1 Table of contents........................................................................................................................................3

2 Glossary of terms .......................................................................................................................................5

3 Absolute Maximum ratings..........................................................................................................................5

4 Pin definition and description ......................................................................................................................6

5 Electrical characteristics .............................................................................................................................7

6 Block diagram.............................................................................................................................................8

7 Principle of operation..................................................................................................................................9

7.1 Initialization ........................................................................................................................................10

7.1.1 Reading configuration ..................................................................................................................11

7.2 Read measurement data ....................................................................................................................12

7.2.1 PTAT data read ...........................................................................................................................12

7.2.2 IR data read.................................................................................................................................12

7.3 Calculation .........................................................................................................................................14

7.3.1 Calculation of absolute chip temperature Ta (sensor temperature) ...............................................14

7.3.2 Example for Ta calculations .........................................................................................................14

7.3.3 Calculation of To ..........................................................................................................................16

7.3.4 Example for To calculations .........................................................................................................18

8 Detailed description, Block description......................................................................................................20

8.1 Pixel position......................................................................................................................................20

8.2 MLX90620 address map ....................................................................................................................21

8.2.1 RAM ............................................................................................................................................21

8.2.2 Internal registers ..........................................................................................................................22

8.2.2.1 Configuration register (0x92) .....................................................................................................22

8.2.2.2 Trimming register (0x93) ...........................................................................................................22

8.2.3 EEPROM.....................................................................................................................................23

8.3 POR...................................................................................................................................................24

8.4 ESD ...................................................................................................................................................24

9 Communication protocol ...........................................................................................................................25

9.1 Communication pins...........................................................................................................................25

9.2 Low level communication protocol ......................................................................................................26

9.2.1 Start / Stop condition....................................................................................................................26

9.2.2 Device addressing .......................................................................................................................26

9.2.3 Acknowledge ...............................................................................................................................26

9.2.4 Low level communication operation..............................................................................................26

9.3 Device modes ....................................................................................................................................27

9.3.1 Normal mode ...............................................................................................................................27

9.4 Communication to IR array.................................................................................................................28

9.4.1 Read command ...........................................................................................................................28

9.4.2 Write configuration register command ..........................................................................................29

9.4.3 Write trimming command .............................................................................................................29

9.5 Communication to EEPROM ..............................................................................................................30

10 Performance Graphs ..............................................................................................................................31

10.1 Temperature accuracy of the MLX90620 ..........................................................................................31

10.2 Field Of View (FOV) .........................................................................................................................32

11 Applications Information..........................................................................................................................33

11.1 Use of the MLX90620 thermometer in SMBus configuration .............................................................33

12 Application Comments............................................................................................................................33

13 Standard information regarding manufacturability of Melexis products with different soldering processes 35

14 ESD Precautions ....................................................................................................................................35

15 FAQ........................................................................................................................................................36

16 Mechanical specification .........................................................................................................................38

16.1 Package outline................................................................................................................................38