RFM92 Datasheet, PDF (112/126 Pages) List of Unclassifed Manufacturers – Low Power Long Range Transceiver Module

RFM92W/93W V3.0
7. Application Information
7.1. Crystal Resonator Specification
Table 42 shows the crystal resonator specification for the crystal reference oscillator circuit of the RFM92W/93W.
This specification covers the full range of operation of the RFM92W/93W and is employed in the reference design.
Table 42 Crystal Specification
Symbol Description
Conditions
Min
Typ
Max Unit
FXOSC XTAL Frequency
-
RS
XTAL Serial Resistance
-
C0
XTAL Shunt Capacitance
-
CFOOT External Foot Capacitance On each pin XTA and XTB
8
32
-
MHz
15
40
Ohms
1.5
3
pF
15
22
pF
CLOAD Crystal Load Capacitance
6
-
12
pF
Notes - the initial frequency tolerance, temperature stability and aging 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.
7.2. Reset of the Chip
A power-on reset of the RFM92W/93W 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 RFM92W/93W, 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 45. POR Timing Diagram
Please note that any CLKOUT activity can also be used to detect that the chip is ready.
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