User's Manual

MPQ Test Radio Z
2005-10-03
LOGITECH CONFIDENTIAL
(Printed on 10/3/2005 ) page 11 of 19
TXD 15 I/O UART Transmit Data: Supports 9.6kbaud, 38.4kbaud, 115.2kbaud.
VCC 11 Power L-ZM2102 supply voltage.
ZEROX 14 I/O
Zero Cross Detection: Zero cross detection signal used on dimmer
modules detecting 120/240V zero crossing.
1. Please note that the SPI interface (MISO, MOSI and SCK) is not available for the Application SW in some Z-Wave protocol
API’s, see [3].
Table 1 L-ZM2102 Signal Description
All signals in Table 1 except RF, VCC and GND are connected directly to the corresponding signals on the
ZW0201 Z-Wave Single Chip on the L-ZM2102 Z-Wave Module. A detailed description of these signals is given
in the ZW0201 Z-Wave Single Chip datasheet [1].
1.3 RF Front-End
1.3.1 RF input/output
The L-ZM2102 Z-Wave Module is equipped with a SAW filter that rejects the unwanted frequencies both
in receive and transmit operations.
Figure 3 L-ZM2102 RF Front-end Circuitry
The RF input/output on the ZW0201 is a single ended input/output that is internally matched to 50 ohm.
1.3.2 Antenna Matching
The L-ZM2102 Z-Wave Module is using an antenna placed on the Application Module, the matching of
the external antenna to 50 ohm (SAW filter impedance) must be made on the Application Module.
As the L-ZM2102 Z-Wave Module is integrated into various products, different types of antennas can be
implemented to get the best RF performance, i.e. range and reliability. In [4], a good overview of the different
antennas is given as well as their pro’s and con’s. In the case the antenna is not 50ohm a matching network must be
implemented between the L-ZM2102 Z-Wave Module and the antenna. The matching network can for example be
a “pi” or a “T” structure as shown in Figure 4.