NRF9E5 Datasheet, PDF (27/104 Pages) List of Unclassifed Manufacturers – 433/868/915MHz RF Transceiver with Embedded 8051 Compatible Microcontroller and 4 Input, 10 Bit ADC

PRODUCT SPECIFICATION
nRF9 E5 Single Chip Transceiver with Embedded Microcontroller and ADC
9.6 Output Frequency
The operating RF-frequency of nRF905 is set in the configuration register by CH_NO
and HFREQ_PLL. The operating frequency is given by:
f_OP = (422.4 + (CH _ NO /10)) ⋅ (1+ HFREQ _ PLL) MHz
When HFREQ_PLL is ‘0’ the frequency resolution is 100kHz and when it is ‘1’ the
resolution is 200kHz.
The application operating frequency has to be chosen to apply with the Short Range
Devise regulation in the area of operation.
Operating frequency
430.0 MHz
433.1 MHz
433.2 MHz
434.7 MHz
HFREQ_PLL
[0]
[0]
[0]
[0]
CH_NO
[001001100]
[001101011]
[001101100]
[001111011]
862.0 MHz
868.2 MHz
868.4 MHz
869.8 MHz
[1]
[001010110]
[1]
[001110101]
[1]
[001110110]
[1]
[001111101]
902.2 MHz
902.4 MHz
927.8 MHz
[1]
[100011111]
[1]
[100100000]
[1]
[110011111]
Table 18 Examples of real operating frequencies.
9.7 Carrier Detect.
When the nRF905 is in ShockBurst ^TM RX, the Carrier Detect (CD) pin is set high if a
RF carrier is present at the channel the device is programmed to. This feature is very
effective to avoid collision of packages from different transmitters operating at the same
frequency. Whenever a device is ready to transmit it could first be set into receive mode
and sense whether or not the wanted channel is available for outgoing data. This forms a
very simple listen before transmit protocol. Operating Carrier Detect (CD) with Reduced
RX Power mode is an extremely power efficient RF system. Typical Carrier Detect level
(CD) is typically 5dB lower than sensitivity, i.e. if sensitivity is –100dBm then the
Carrier Detect function will sense a carrier wave as low as –105dBm. Below –105dBm
the Carrier Detect signal will be low, i.e. 0V. Above –95dBm the Carrier Detect signal
will be high, i.e. Vdd. Between approximately -95 to -105 the Carrier Detect Signal will
toggle.
Main office: Nordic Semiconductor ASA - Vestre Rosten 81, N-7075 Tiller, Norway -Phone [phone] - Fax [phone]
Revision: 1.1
Page 27 of 104
June 2004