CC2430 Datasheet, PDF (184/234 Pages) Texas Instruments – A True System-on-Chip solution for 2.4 GHz IEEE 802.15.4 / ZigBee-TM

CC2430
14.29 Input / Output Matching
The RF input / output is differential (RF_N
and RF_P). In addition there is supply
switch output pin (TXRX_SWITCH) that
must have an external DC path to RF_N
and RF_P.
In RX mode the TXRX_SWITCH pin is at
ground and will bias the LNA. In TX mode
the TXRX_SWITCH pin is at supply rail
voltage and will properly bias the internal
PA.
14.30 Transmitter Test Modes
CC2430 can be set into different transmit
test modes for performance evaluation.
The test mode descriptions in the following
sections requires that the chip is first reset,
the crystal oscillator is selected using the
CLKCON register and that the crystal
oscillator has stabilized.
14.30.1 Unmodulated carrier
An unmodulated carrier may be
transmitted
by
setting
MDMCTRL1L.TX_MODE to 2, writing
The RF output and DC bias can be done
using different topologies. Some are
shown in Figure 6 on page 30.
Component values are given in Table 24
on page 31. If a differential antenna is
implemented, no balun is required.
If a single ended output is required (for a
single ended connector or a single ended
antenna), a balun should be used for
optimum performance.
0x1800 to the DACTSTH:DACTSTL
registers and issue a STXON command
strobe. The transmitter is then enabled
while the transmitter I/Q DACs are
overridden to static values. An un-
modulated carrier will then be available on
the RF output pins.
A plot of the single carrier output spectrum
from CC2430 is shown in Figure 54 below.
CC2430 PRELIMINARY Data Sheet (rev. 1.03) SWRS036A
Page 184 of 232