MRF89XA-I/MQ Microchip Technology, MRF89XA-I/MQ Datasheet - Page 98

• Manufacturer Part Number: MRF89XA-I/MQ
• Description: TXRX ISM SUB-GHZ ULP 32QFN
• Manufacturer: Microchip Technology

Specifications of MRF89XA-I/MQ

• Package / Case: 32-WFQFN Exposed Pad
• Frequency: 863MHz ~ 870MHz, 902MHz ~ 928MHz, 950MHz ~ 960MHz
• Data Rate - Maximum: 200kbps
• Modulation Or Protocol: FSK, OOK
• Applications: ISM
• Power - Output: 12.5dBm
• Sensitivity: -113dBm
• Voltage - Supply: 2.1 V ~ 3.6 V
• Current - Receiving: 3mA
• Current - Transmitting: 25mA
• Data Interface: PCB, Surface Mount
• Antenna Connector: PCB, Surface Mount
• Operating Temperature: -40°C ~ 85°C
• Number Of Receivers: 1
• Number Of Transmitters: 1
• Wireless Frequency: 863 MHz to 870 MHz, 902 MHz to 928 MHz, 950 MHz to 960 MHz
• Interface Type: SPI
• Noise Figure: - 112 dBc
• Output Power: - 8.5 dBm, + 12.5 dBm
• Operating Supply Voltage: 2.1 V to 3.6 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Maximum Data Rate: 256 Kbps
• Maximum Supply Current: 25 mA
• Minimum Operating Temperature: - 40 C
• Modulation: FSK
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Memory Size: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

4.1
The optimum load for the RF port at a given frequency
band is listed in Table 4-1. These load values in the
table are expected by the RF port pins to have as an
antenna load for maximum power transfer. For all
antenna applications, an RF choke inductor (L2) must
be included during transmission because the RF out-
puts are of open-collector type.
4.2
The MRF89XA is single-ended and has an unbalanced
input/output impedance close to 30-j25. Therefore, it
only requires a matching circuit to the SAW filter and
antenna. C11, C12, and L6, L1, C4, and C5 are tuned
to provide that impedance (30+j25) to the RFIO pin
(pin 31). In this case, the transceiver will be able to
transfer all power toward the antenna. This impedance
is called Optimum Load Impedance. L2 is a RF choke
inductor. L3 and L4 are basically VCO inductors. The
details are shown in Figure 4-1.
TABLE 4-1:
DS70622B-page 98
MRF89XA
868 MHz TA0801A
915 MHz TA0281A
Band
RF Transmitter Matching
Antenna Components
FL1
ANTENNA LOAD VALUES
FOR 868 MHz AND 915 MHz
FREQUENCY BANDS
1.8 pF
1.8 pF
C5
22 pF
30 pF
C4
8.2 nH
10 nH
L1
Preliminary
4.3
FL1 is a SAW filter. While in Transmitting mode, the
SAW filter is used to suppress the harmonics. While in
Receiving mode, the SAW filter is used to reject the
image frequencies and out-of-band interfering signals.
4.3.1
Figure 4-2 and Figure 4-3 illustrates the plots of the
SAW filter used in the application circuit. The plots
shown are representative. For exact specifications,
refer to the SAW Filter manufacturer data sheet.
SAW FILTER
SAW FILTER PLOT
© 2010 Microchip Technology Inc.