MRF89XAM9A_12 Datasheet, PDF (7/36 Pages) Microchip Technology – 915 MHz Ultra Low-Power Sub-GHz Transceiver Module

1.3 Operation
The MRF89XAM9A module is based on the
Microchip’s MRF89XA Ultra Low-Power, Integrated
ISM Band Sub-GHz Transceiver IC. Data
communication and module configuration are
documented in the “MRF89XA Ultra Low-Power,
Integrated ISM Band Sub-GHz Transceiver Data
Sheet” (DS70622).
The following section emphasizes operational settings
that are unique to the MRF89XAM9A module design
that must be followed for the operation.
1.3.1 RESET
Pin 2 of the module, Reset, allows an external reset of
the MRF89XA IC. Reset is connected to the TEST8 pin
of the MRF89XA IC. During normal operations of the
MRF89XAM9A, the Reset pin should be held in a high
impedance state. For more information on assertion of
the RESET pin, refer to “Section 3.1.2 Manual Reset”
in the “MRF89XA Data Sheet” (DS70622).
MRF89XAM9A
1.3.2 CRYSTAL FREQUENCY
When calculating frequency deviation, bit rate, receiver
bandwidth, and PLL R, P and S values, use crystal
frequency f_xtal = 12.8 MHz.
1.3.3 CLOCK OUTPUT (CLKOUT)
The CLKOUT pin 19 of the MRF89XA IC is not used on
the module. Ensure that the CLKOUT signal is disabled
to minimize current consumption.
1.3.4 FREQUENCY BAND SELECT
The Frequency Band Select bits (FBS<1:0>) in the
GCONREG<4:3> should be set for target channel
range 902–915 MHz FBS<1:0> = ‘00’ or 915–928 MHz
FBS<1:0> = ‘01’.
1.3.5 VCO TANK TRIM VALUE
The VCO Trim bits (VCOT<1:0>) in the
GCONREG<2:1> should be set for VCOT<1:0> = ‘01’
for the inductor values of the module.
1.3.6 BIT RATE
The maximum bit rate value will be limited to 28 kbps
for OOK modulation due to the crystal frequency of
12.8 MHz.
 2011-2012 Microchip Technology Inc.
Preliminary
DS75017B-page 7