MC1320x RF Daughter Card, Rev. 1.2
10
Freescale Semiconductor
RF Circuit
5.1.0.3
Power Connections
J101 Pin 39 (J102 pin 1) provides the supply voltage to the RF Daughter Card. Voltage on this line should
never exceed 16.0 VDC and the nominal voltage supply should not exceed 16.0 VDC. J101 Pin 40 (J102
pin 3) is ground.
NOTE
MCU connection signals are dependent on the on-board voltage regulator.
If R105, D101, and C101 are mounted and R115 is removed, J101 Pin 39
will provide the interface supply voltage which must never exceed 3.6 V.
Nominal supply voltage should never exceed 3.4 V.
5.1.0.4
Non-MCU Connections
Header J105 provides connections to a number of MC1320x contacts for non-MCU connections. As
already stated, the RXTXEN and ATTN lines are available at J105 for external control using switches or
other hardware. The MC1320x GPIO is also available for connection to external hardware.
6
RF Circuit
The MC1320x has an internal TX/RX switch. This feature allows for an external RF circuit that has a very
low component count. The MC1320x requires only a few passive components and a balun to provide an
interface to an antenna or a 50 ohm circuit.
Figure 6-1
shows a schematic for only the RF portion of the
MC1320x Daughter Card.
Figure 6-1. RF Portion of 20x Daughter Card
