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
Page 10 of 45
Pad number Function Description
9 VDD_3.3V Module power supply
8 VDD_PA RF power amplifier power supply
1, 16, 26, 45,
48, 50
GND
Ground, connected together internally but should all be connected directly to a solid ground plane
51 GNDPAD
Thermal ground pad, should be connected to a solid ground plane with multiple vias for improved
thermal conductance
40 Not Connected
49 ANT Antenna connection pad in N variant of the module, in other variants not connected
25 VBUS USB VBUS input
13 MCLR
Module reset, also used for programming using a Microchip tool. Internal pull-up, can be left
floating or connected to ground through a 100nF capacitor for delayed power-up reset (note:
Microchip ICSP programming tools will not work with a capacitor)
Table 1: Single function pad descriptions