RF65 Datasheet, PDF (66/72 Pages) List of Unclassifed Manufacturers – Low Power Integrated UHF Receiver With -120dBm High Sensitivity

ADVANCED COMMUNICATIONS & SENSING
RF65
DATASHEET
7. Application Information
7.1. Crystal Resonator Specification
Table 26 shows the crystal resonator specification for the crystal reference oscillator circuit of the RF65. This
specification covers the full range of operation of the RF65 and is employed in the reference design.
Table 26 Crystal Specification
Symbol Description
Conditions
Min
Typ
Max Unit
FXOSC XTAL Frequency
26
-
32 MHz
RS
XTAL Serial Resistance
-
30
140 ohms
C0
XTAL Shunt Capacitance
-
2.8
7
pF
CLOAD External Foot Capacitance On each pin XTA and XTB
8
16
22 pF
Notes - the initial frequency tolerance, temperature stability and ageing performance should be chosen in accordance
with the target operating temperature range and the receiver bandwidth selected.
- the loading capacitance should be applied externally, and adapted to the actual Cload specification of the XTAL.
- A minimum XTAL frequency of 28 MHz is required to cover the 863-870 MHz band, 29 MHz for the 902-928 MHz
band
7.2. Reset of the Chip
A power-on reset of the RF65 is triggered at power up. Additionally, a manual reset can be issued by controlling pin 6.
7.2.1. POR
If the application requires the disconnection of VDD from the RF65, despite of the extremely low Sleep Mode current, the
user should wait for 10 ms from of the end of the POR cycle before commencing communications over the SPI bus. Pin 6
(Reset) should be left floating during the POR sequence.
VDD
Pin 6
(output)
Undefined
Wait for Chip is ready from
10 ms this point on
Figure 34. POR Timing Diagram
Please note that any CLKOUT activity can also be used to detect that the chip is ready.
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