CC2400 Chipcon AS, CC2400 Datasheet - Page 48

• Manufacturer Part Number: CC2400
• Description: 2.4 GHz RF Transceiver
• Manufacturer: Chipcon AS

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 done
using
circuits are shown in Figure 3 and Figure
4. Component values are given in Table 2.
Chipcon AS
different
SmartRF
topologies.
®
CC2400 PRELIMINARY Datasheet (rev. 1.1), 2003-10-02
Application
SmartRF
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. The balun can be
realized using discrete inductors and
capacitors.
Using a differential antenna, no balun is
required.
If the power amplifier is configured for
single ended use, then a simpler matching
network can be used. The output power
and sensitivity will however be reduced.
The RF_N pin should then be terminated
in a grounded capacitor and the RF_P pin
should
TXRX_SWITCH pin.
have
a
®
DC
CC2400
path
Page 48 of 73
to
the