Product Specs

PRELIMINARY PRODUCT SPECIFICATION
nRF24L01 Single Chip 2.4 GHz Radio Transceiver
Nordic Semiconductor ASA - Vestre Rosten 81, N-7075 Tiller, Norway - Phone [phone] - Fax [phone]
Page 31 of 38
Revision: 1.1
November 2005
PCB layout and de-coupling guidelines
A well-designed PCB is necessary to achieve good RF performance. Keep in mind
that a poor layout may lead to loss of performance, or even functionality, if due care is
not taken. A fully qualified RF-layout for the nRF24L01 and its surrounding
components, including matching networks, can be downloaded from
www.nordicsemi.no.
A PCB with a minimum of two layers including a ground plane is recommended for
optimum performance. The nRF24L01 DC supply voltage should be de-coupled as
close as possible to the VDD pins with high performance RF capacitors, see Table 16.
It is preferable to mount a large surface mount capacitor (e.g. 4.7F tantalum) in
parallel with the smaller value capacitors. The nRF24L01 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
nRF24L01 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 have via holes as close as possible to the VSS pads. At least 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.