SX1231 SEMTECH [Semtech Corporation], SX1231 Datasheet - Page 73

• Manufacturer Part Number: SX1231
• Description: Low Power Integrated UHF Transceiver
• Manufacturer: SEMTECH [Semtech Corporation]

7. Application Information
7.1. Crystal Resonator Specification
Table 29 shows the crystal resonator specification for the crystal reference oscillator circuit of the SX1231. This
specification covers the full range of operation of the SX1231 and is employed in the reference design.
Table 29 Crystal Specification
Notes - the initial frequency tolerance, temperature stability and ageing performance should be chosen in accordance
7.2. Reset of the Chip
A power-on reset of the SX1231 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 SX1231, 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.
Please note that any CLKOUT activity can also be used to detect that the chip is ready.
Rev 2 - Nov 2009
ADVANCED COMMUNICATIONS & SENSING
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
Symbol
FXOSC
RS
C0
CLOAD
Description
XTAL Frequency
XTAL Serial Resistance
XTAL Shunt Capacitance
External Foot Capacitance
VDD
Pin 6
(output)
Undefined
Figure 36. POR Timing Diagram
Conditions
On each pin XTA and XTB
Wait for
10 ms
Page 73
Chip is ready from
this point on
Min
26
8
-
-
Typ
2.8
30
16
-
Max
140
32
22
7
DATASHEET
www.semtech.com
SX1231
MHz
ohms
pF
pF
Unit