CC2400 Datasheet, PDF (50/84 Pages) Texas Instruments – 2.4 GHz Low-Power RF Transceiver

CC2400
Table 20. 16MHz crystal oscillator component values for C_L=16pF
44 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.
The RF output and DC bias can be
achieved using different topologies.
Application circuits are shown in Figure 3
and Figure 4. Component values are given
in Table 11.
If a single ended output is required (for a
single ended connector or a single ended
antenna), a balun should be used. The
balun can be realized using discrete
inductors and capacitors.
Using a differential antenna, no balun is
required.
45 Typical performance graphs
The following graphs show how some
important parameters vary with
temperature. These graphs show typical
performance as a function of temperature,
and should be used as design guidance
only.
25
24
23
22
21
20
19
18
17
16
15
-40
-20
0
20
40
60
80
Temp (deg C)
Figure 24 Typical RX and TX current vs. temperature
RX Current
TX Current
SWRS042A
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