CC2550 Datasheet, PDF (13/50 Pages) Texas Instruments – Single Chip Low Cost Low Power RF-Transmitter

CC2550
Details of each configuration register can be
found in section 33, starting on page 32.
Figure 4 shows a simplified state diagram that
explains the main CC2550 states, together with
typical usage and current consumption. For
detailed information on controlling the CC2550
state machine, and a complete state diagram,
see section 23, starting on page 23.
SIDLE ^{SPWD or wake-on-radio (WOR)}
Sleep
Lowest power mode.
Register values are lost.
Typ. current consumption:
200nA.
Default state when the radio is not
receiving or transmitting. Typ.
current consumption: 1.2mA.
IDLE
CSn=0
Used for calibrating frequency
synthesizer upfront (entering
transmit mode can then be
done quicker). Transitional
state. Typ. current
consumption: 6.8mA.
SCAL
SXOFF
Manual freq.
synth. calibration
CSn=0
SRX or STX or SFSTXON or wake-on-radio (WOR)
Crystal
oscillator off
All register values are
retained. Typ. current
consumption; 0.18mA.
Frequency synthesizer is on,
ready to start transmitting.
Transmission starts very
quickly after receiving the
STX command strobe.Typ.
current consumption: 6.8mA.
SFSTXON
Frequency
synthesizer on
Frequency
synthesizer startup,
optional calibration,
settling
Frequency synthesizer is turned on, can optionally be
calibrated, and then settles to the correct frequency.
Transitional state. Typ. current consumption: 4.7mA.
STX
STX
TXOFF_MODE=01
Typ. current consumption:
12.8mA at -12dBm output,
16.4mA at -6dBm output,
22.8mA at 0dBm output.
Transmit mode
TXOFF_MODE=00
In FIFO-based modes,
transmission is turned off and
this state entered if the TX
FIFO becomes empty in the
middle of a packet. Typ.
current consumption: 1.2mA.
TX FIFO
underflow
Optional transitional state. Typ. _{Optional freq.}
current consumption: 6.8mA. _{synth. calibration}
SFTX
IDLE
Figure 4: Simplified state diagram, with typical usage and current consumption
16 Configuration Software
CC2550 can be configured using the SmartRF^®
Studio software, available for download from
http://www.chipcon.com. The SmartRF^® Studio
software is highly recommended for obtaining
optimum register settings, and for evaluating
performance and functionality. A screenshot of
the SmartRF^® Studio user interface for CC2550
is shown in Figure 5.
Preliminary Data Sheet (rev. 1.1) SWRS039
Page 13 of 51