nRF903 Nordic VLSI, nRF903 Datasheet - Page 25

• Manufacturer Part Number: nRF903
• Description: Multichannel RF Transceiver 433/868/915MHz
• Manufacturer: Nordic VLSI

PRODUCT SPECIFICATION
Nordic VLSI ASA
Revision: 3.1
868.0
A 868MHz system module is to be designed. The operating channel of the unit
is channel #5. The transceiver units are operating within a small confined area.
System channel organisation and ETSI frequency allocations are shown in
Figure 18.
The same crystal is shared by the micro-controller and transceiver. When
applying power, nRF903 is set to Standby-mode (STBY = ’1’, PWR_DWN =
’0’), a 11.0592MHz system clock is then available to the micro-controller at the
CLK_OUT-pin after 0.8 ms (see Table 10).
The micro-controller then sets the transceiver to normal operation, receive
mode (STBY = ’0’, PWR_DWN = ’0’, TXEN = ’0’) for configuration (Receive
mode is chosen during configuration in order to avoid unintentional
transmission at an unwanted frequency).
The configuration word is calculated as follows (refer to Table 6);
1. Setting frequency band:
2. Calculating channel frequency location:
3. Setting output power
868.1
Channel #0
Low Duty-Cycle Band (<1%)
The system operates in the 868MHz LPRD-band, and FB is thus set to
01
The center frequency of Channel #5 is 868.9536MHz.
CH is found by solving for CH in the equation given in Table 6;
CH=5 (00000101
The operational range is limited, and the output power is therefore
reduced to a minimum in order to minimise current consumption in
transmit mode. P
8dBm.
868.2
-
Figure 18. 868MHz LPRD-band, channel organisation
b
.
Vestre Rosten 81, N-7075 Tiller, Norway
868.3
Channel #1
868.4
out
b
)
Channel #2
is set to 0 (00
868.5
QhtrÃ!$ÂsÃ"!
25KHz channel
868.6
spacing band
Channel #3
b
), resulting in an output power of -
868.7
-
Phone [phone]
Channel #4
868.8
Very Low Duty-Cycle Band (<0.1%)
868.9
Channel #5
869.0
-
Fax [phone]
December 2002
869.1
Channel #6
869.2
f [MHz]