Data Sheet
Table Of Contents
- 1 Design guidelines
- 2 Ordering Information
- 3 Pinout and Terminal Descriptions
- 4 Packaging
- 5 Power control
- 6 Interfaces
- 7 Block diagram
- 8 Example schematics
- 9 802.11 Radio
- 10 Firmware
- 11 Host interfaces
- 12 Electrical characteristics
- 13 RF Characteristics
- 14 Physical dimensions
- 15 Layout guidelines
- 16 Soldering recommendations
- 17 Certifications
- 18 Qualified Antenna Types for WF121-E
Silicon Labs
TABLE OF CONTENTS
1 Design guidelines ..........................................................................................................................................7
2 Ordering Information......................................................................................................................................8
3 Pinout and Terminal Descriptions .................................................................................................................9
4 Packaging ................................................................................................................................................... 12
5 Power control .............................................................................................................................................. 15
5.1 Power supply requirements ............................................................................................................... 15
5.2 Power saving functionality ................................................................................................................. 15
5.3 Reset .................................................................................................................................................. 16
6 Interfaces .................................................................................................................................................... 17
6.1 General Purpose I/O pins .................................................................................................................. 17
6.2 Serial ports ......................................................................................................................................... 17
6.3 I
2
C/SPI ............................................................................................................................................... 18
6.4 USB .................................................................................................................................................... 18
6.5 Ethernet ............................................................................................................................................. 19
6.6 Analog inputs ..................................................................................................................................... 20
6.7 Microcontroller programming interface .............................................................................................. 20
6.8 RF Debug Interface ........................................................................................................................... 21
6.9 CPU Clock ......................................................................................................................................... 21
6.10 32.768 kHz External Reference Clock ............................................................................................... 22
7 Block diagram ............................................................................................................................................. 23
8 Example schematics................................................................................................................................... 24
9 802.11 Radio .............................................................................................................................................. 25
9.1 Wi-Fi Receiver ................................................................................................................................... 25
9.2 Wi-Fi Transmitter ............................................................................................................................... 25
9.3 Regulatory domains ........................................................................................................................... 25
10 Firmware ................................................................................................................................................ 26
11 Host interfaces ....................................................................................................................................... 27
11.1 UART ................................................................................................................................................. 27
11.2 USB .................................................................................................................................................... 27
11.3 SPI ..................................................................................................................................................... 27
12 Electrical characteristics ........................................................................................................................ 28
12.1 Absolute maximum ratings ................................................................................................................ 28
12.2 Recommended operating conditions ................................................................................................. 28
12.3 Input/output terminal characteristics .................................................................................................. 29
12.4 Digital ................................................................................................................................................. 29
12.5 Reset .................................................................................................................................................. 29
12.6 Power consumption ........................................................................................................................... 30