User's Manual

38
Atmel AVR2092
8427A-AVR-10/11
9 Table of contents
Features............................................................................................... 1
1 Introduction ...................................................................................... 1
2 Disclaimer......................................................................................... 2
3 Overview........................................................................................... 3
4 Functional description..................................................................... 4
4.1 Interface connector specification......................................................................... 4
4.1.1 Atmel ATmega1281 configuration ............................................................................. 5
4.1.2 Atmel ATmega644 configuration ............................................................................... 5
4.2 ID EEPROM ........................................................................................................ 6
4.3 Supply current sensing........................................................................................ 8
4.4 Radio transceiver reference clock ....................................................................... 8
4.5 RF section ........................................................................................................... 9
5 PCB layout description ................................................................. 10
5.1 PCB detail 1 – balanced RF pin fan out ............................................................ 11
5.2 PCB detail 2 – RF switch................................................................................... 12
5.3 PCB detail 3 – crystal routing ............................................................................ 12
5.4 PCB detail 4 – transceiver analog GND routing................................................ 13
5.5 PCB detail 5 – digital GND routing and shielding.............................................. 14
5.6 PCB detail 6 – transceiver RF tuning ................................................................ 15
5.7 Ceramic antenna ............................................................................................... 16
5.7.1 Antenna design study .............................................................................................. 16
5.7.2 Antenna design-in ................................................................................................... 19
5.7.3 Antenna tuning ........................................................................................................ 20
5.7.4 Final board antenna radiation pattern...................................................................... 24
6 Mechanical description ................................................................. 28
7 Electrical characteristics............................................................... 29
7.1 Absolute maximum ratings ................................................................................ 29
7.2 Recommended operating range........................................................................ 29
7.3 Current consumption ......................................................................................... 29
8 Abbreviations ................................................................................. 31
Appendix A – PCB design data........................................................ 32
A.1 Schematic..................................................................................................... 32
A.2 Assembly drawing ........................................................................................ 33
A.3 Bill of materials ............................................................................................. 34
Appendix B – Radio certification..................................................... 35
B.1 United States (FCC) ..................................................................................... 35