NRF905 NORDIC SEMICONDUCTOR, NRF905 Datasheet - Page 27

• 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
8.8
PCB Layout and Decoupling Guidelines
nRF905 is an extremely robust RF device due to internal voltage regulators and
requires the minimum of RF layout protocols. However the following design rules
should still be incorporated into the layout design.
A PCB with a minimum of two layers including a ground plane is recommended for
optimum performance. The nRF905 DC supply voltage should be decoupled as close
as possible to the VDD pins with high performance RF capacitors. It is preferable to
mount a large surface mount capacitor (e.g. 4.7 F tantalum) in parallel with the
smaller value capacitors. The nRF905 supply voltage should be filtered and routed
separately from the supply voltages of any digital circuitry.
Long power supply lines on the PCB should be avoided. All device grounds, VDD
connections and VDD bypass capacitors must be connected as close as possible to the
nRF905 IC. For a PCB with a topside RF ground plane, the VSS pins should be
connected directly to the ground plane. For a PCB with a bottom ground plane, the
best technique is to place via holes as close as possible to the VSS pins. A minimum
of one via hole should be used for each VSS pin.
Full swing digital data or control signals should not be routed close to the crystal or
the power supply lines.
A fully qualified RF-layout for the nRF905 and its surrounding components,
including
antennas
and
matching
networks,
can
be
downloaded
from
www.nordicsemi.no.
Main office: Nordic Semiconductor ASA
- Vestre Rosten 81, N-7075 Tiller, Norway
- Phone [phone] -Fax [phone]
Revision: 1.4
Page 27 of 42
June 2006