NRF9E5 Datasheet, PDF (17/104 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
7 ANALOG INTERFACE
7.1 Crystal Specification
Tolerance includes initially accuracy and tolerance over temperature and aging.
Frequency
4MHz
8MHz
12MHz
16MHz
20MHz
C_L
12pF
12pF
12pF
12pF
12pF
ESR
150Ω
100Ω
100Ω
100Ω
100Ω
C_0max
7.0pF
7.0pF
7.0pF
7.0pF
7.0pF
Tolerance @
868/915 MHz
±30ppm
±30ppm
±30ppm
±30ppm
±30ppm
Tolerance @
433 MHz
±60ppm
±60ppm
±60ppm
±60ppm
±60ppm
Table 13 Crystal specification of nRF9E5.
To achieve a crystal oscillator solution with low power consumption and fast start-up
time, it is recommended to specify the crystal with a low value of crystal load
capacitance. Specifying C_L =12pF is acceptable, but it is possible to use up to 16pF.
Specifying a lower value of crystal parallel equivalent capacitance, Co=1.5pF is also
good, but this can increase the price of the crystal itself. Typically Co=1.5pF at a crystal
specified for Co_max=7.0pF.
7.2 Antenna Output
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 200-700Ω. The optimum differential load impedance at the antenna ports is
given as:
900MHz
430MHz
225Ω+j210
300Ω+j100
A low load impedance (for instance 50Ω) 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.
7.3 ADC Inputs
The Analog to digital converter has four analog input channels and one reference
voltage input. Analog input is selected with CHSEL in the ADC_CONFIG_REG.
7.4 Current Reference
To get accurate internal biasing, an external low tolerance resistor is used. A resistor of
22kΩ and 1% accuracy should be connected between the pin IREF and ground for
proper operation of nRF9E5.
Main office: Nordic Semiconductor ASA - Vestre Rosten 81, N-7075 Tiller, Norway -Phone [phone] - Fax [phone]
Revision: 1.1
Page 17 of 104
June 2004