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 31 of 45
Consumption type
Curre
nt
Unit Description
Transmit consumption 143 mA
Typical average module consumption during
full rate data
transfer, system does not enter deep sleep due to constant data
traffic (Ethernet MAC enabled for testing)
Receive consumption 127 mA
Typical average module consumption during
full rate data
transfer, system does not enter deep sleep due to constant data
traffic
Access point mode 108 mA
Typical average idle current when configured as an AP, does
not enter deep sleep due to AP mode requirements
Idle, associated 1.7-10 mA
Typical average with DTIM=1, beacon interval=100ms,
including keep-alive traffic
and CPU timed wakeups, power
saving enabled (typically 1.7mA when no broadcast traffic is
present)
Idle, associated 35 mA
Typical average with DTIM=1, beacon interval=100ms,
including keep-
alive traffic and CPU timed wakeups, power
saving disabled
Idle, unassociated 166 µA
Typical sleep current with Wi-
Fi chip on and initialized but
unassociated. Associating to an access point from this state
usually happens in less than a second, depending on
DHCP/static IP settings and security opti
ons. Peripherals
disabled.
Deep Sleep 55 µA
Deep sleep (Wi-Fi power
supply disabled internally, CPU
sleeping, all peripherals except watchdog and GPIO interrupts
off). Waking the Wi-Fi from this state requires reinitialization of
the Wi-Fi core and the ti
me from wakeup to access point
association can take up to 10 seconds
Table 18: Typical power consumption, module total
All average readings are made with a 3.3V power supply, using the DKWF121 board and comparing Fluke
289 True RMS multimeter average readings with oscilloscope derived mode-specific consumption profiles.
Measuring currents varying several orders of magnitude within microseconds may give varying results with
different instruments and the measurement method should be considered carefully.
Associated idle consumption is heavily dependent on the access point used, the local broadcast traffic, power
save timeouts set by the user and enabled peripherals. Transmit and receive consumptions are heavily
dependent on the RF field strength and thus the over-air bitrate, which determines the time taken to transfer
the required data. WF121 automatically enters power saving modes when not actively transferring data, and
the shorter the time taken to transfer data over the Wi-Fi, the more time it can spend in power saving modes.