NRF905 NORDIC SEMICONDUCTOR, NRF905 Datasheet - Page 25

• Manufacturer Part Number: NRF905
• Description: IC, TRANSCEIVER, 430 928MHZ, SMD
• Manufacturer: NORDIC SEMICONDUCTOR

Specifications of NRF905

• Transmitting Current: 9mA
• Data Rate: 50Kbps
• Frequency Range: 430MHz To 928MHz
• Modulation Type: GFSK
• Sensitivity Dbm: -100dBm
• Rf Ic Case Style: QFN
• No. Of Pins: 32
• Supply Voltage Range: 1.9V To 3.6V
• Output Power: 10dBm
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

PRODUCT SPECIFICATION
nRF905 Single Chip 433/868/915 MHz Radio Transceiver
8.4
The “ANT1 & ANT2” output pins provide a balanced RF output to the antenna. The
pins must have a DC path to VDD_PA, either via a RF choke or via the center point
in a dipole antenna. The load impedance seen between the ANT1/ANT2 outputs
should be in the range 200-700 . The optimum differential load impedance at the
antenna ports is given as:
A low load impedance (for instance 50 ) can be obtained by fitting a simple
matching network or a RF transformer (balun). Further information regarding balun
structures and matching networks may be found in the Application Examples chapter.
8.5
The power amplifier in nRF905 can be programmed to four different output power
settings by the configuration register. By reducing output power, the total TX current
is reduced.
8.6
The modulation of nRF905 is Gaussian Frequency Shift Keying (GFSK) with a data-
rate of 100kbps. Deviation is 50kHz. GFSK modulation results in a more bandwidth
effective transmission-link compared with ordinary FSK modulation.
The data is internally Manchester encoded (TX) and Manchester decoded (RX). That
is, the effective symbol-rate of the link is 50kbps. By using internally Manchester
encoding, no scrambling in the microcontroller is needed.
Main office: Nordic Semiconductor ASA
Revision: 1.4
Antenna Output
Output Power Adjustment
Modulation
Power setting
900MHz
430MHz
Conditions: VDD = 3.0V, VSS = 0V, T
Table 13 RF output power setting for the nRF905.
00
01
10
11
- Vestre Rosten 81, N-7075 Tiller, Norway
225 +j210
300 +j100
RF output power
-10 dBm
10 dBm
-2 dBm
6 dBm
Page 25 of 42
A
= 27ºC, Load impedance = 400 .
DC current consumption
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14.0 mA
20.0 mA
30.0 mA
9.0 mA
June 2006