nRF903 Nordic VLSI, nRF903 Datasheet - Page 7

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

PRODUCT SPECIFICATION
Figure 4 shows the user interface of nRF903 which consists of a total of 9 digital
input/output pins.
The interface is divided into two main functions: Configuration and Mode-control. In
addition, a receiver carrier sense signal (C_SENSE) and a microprocessor clock
output signal (CLK_OUT) is available.
C_SENSE is stable low when no carrier is detected in the received channel. As the
power-level increases, the average duty-cycle of the C_SENSE signal increases to the
point where it is stable high for input power levels approx. 10dB above the sensitivity
limit. A positive transition on the C_SENSE-pin may be used to initiate the listening
procedure in the micro-controller used to process data.
CLK_OUT is the full-swing 11.0592MHz reference frequency divided by 1,2,4 or 8.
At high output frequencies the peak-to-peak voltage is reduced in order to keep
switching noise down.
Configuration is performed by clocking a 14-bit configuration word into a shift-
register (see Table 6).
These 14 bits are decoded into the corresponding frequency band, channel, output
power and output clock frequency. The Serial Peripheral Interface (SPI) consists of
the pins CFG_DATA, CFG_CLK and CS. Once configured, these pins are not used
unless one or more of the parameters above need to be changed.
Nordic VLSI ASA
Revision: 3.1
-
PWR_DWN
CFG_DATA
C_SENSE
CFG_CLK
CS
CLK_OUT
DATA
TXEN
STBY
Vestre Rosten 81, N-7075 Tiller, Norway
Figure 4. nRF903 user interface
pin 26
pin 25
pin 19
pin 20
pin 11
pin 10
pin 12
pin 18
pin 16
QhtrÃ&ÂsÃ"!
Mode control
SPI-configuration
-
Q5) 
Phone [phone]
-
Fax [phone]
December 2002