MRF49XA-I/ST Microchip Technology, MRF49XA-I/ST Datasheet - Page 72

• Manufacturer Part Number: MRF49XA-I/ST
• Description: IC RF TXRX 433/868/915 16-TSSOP
• Manufacturer: Microchip Technology

Specifications of MRF49XA-I/ST

• Package / Case: 16-TSSOP
• Frequency: 433MHz, 868MHz, 915MHz
• Data Rate - Maximum: 256kbps
• Modulation Or Protocol: FHSS, FSK
• Applications: Home / Industrial Automation, Remote Access, Security Alarms
• Power - Output: 7dbm
• Sensitivity: -110dBm
• Voltage - Supply: 2.2 V ~ 3.8 V
• Current - Receiving: 11mA
• Current - Transmitting: 15mA
• Data Interface: PCB, Surface Mount
• Antenna Connector: PCB, Surface Mount
• Operating Temperature: -40°C ~ 85°C
• Number Of Receivers: 1
• Number Of Transmitters: 2
• Wireless Frequency: 433 MHz to 915 MHz
• Output Power: + 7 dBm
• Operating Supply Voltage: 2.5 V, 3.3 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: - 40 C
• Modulation: FHSS, FSK
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Memory Size: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 579-MRF49XA-1/ST

3.19
The RX-TX frequency offset occurs due to the differ-
ences in the actual reference frequency. To minimize this
error, the same crystal type and the same PCB layout
should be used for the crystal placement on the RX and
TX PCBs. Also, see Section 3.6 “Crystal Selection
Guidelines”.
To verify the possible RX-TX offset, it is recommended
to measure the CLK output of both transceivers with a
high level of accuracy. Do not measure the output at the
RFXTL pin as the measurement process itself might
change the reference frequency. As the carrier frequen-
cies are derived from the reference frequency, having
identical reference frequencies, and nominal frequency
settings at the TX and RX side, there should be no offset
if the CLK signals have identical frequencies.
DS70590B-page 70
MRF49XA
RX-TX Frequency Alignment
Method
Preliminary
The actual RX-TX offset can be monitored by using the
AFC status data included in the STSREG of the
receiver. By reading out the STSREG, the actual
measured offset frequency can be reported. In order to
get accurate values, the AFC has to be disabled during
the read by clearing the FOFEN bit in AFCCREG.
The registers associated with RX-TX alignment
procedures are:
• STSREG (see Register 2-1)
• AFCCREG (see Register 2-3)
• RXCREG (see Register 2-7)
• PMCREG (see Register 2-13)
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