MRF49XAT-I-ST Datasheet, PDF (9/102 Pages) Microchip Technology – ISM Band Sub-GHz RF Transceiver

2.0 HARDWARE DESCRIPTION
The MRF49XA is an integrated, single chip ISM Band
Sub-GHz Transceiver. A simplified architectural block
diagram of the MRF49XA is shown in Figure 2-1.
The frequency synthesizer is clocked by an external
10 MHz crystal and generates the 433, 868 and 915
MHz radio frequency. The receiver with a Zero-IF
architecture consists of the following components:
• LNA
• Down Conversion Mixers
• Channel Filters
• Baseband Limiting Amplifiers
• Receiver Signal Strength Indicator
The transmitter with a direct conversion architecture
has a typical output power of +7 dBm. An internal
transmit/receive switch combines the transmitter and
receiver circuits into differential RFP and RFN pins.
These pins are connected to the impedance matching
circuitry (Balun) and to the external antenna connected
to the device.
The device operates in the low-voltage range of 2.2V–
3.8V, and in Sleep mode, it operates at a very low-current
state, typically 0.3 μA.
MRF49XA
The quality of the data is checked or validated using the
RSSI and DQI blocks built into the transceiver. Data is
buffered in transmitter registers and receiver FIFOs.
The AFC feature allows the use of a low-accuracy and
low-cost crystal. The CLKOUT is used to clock the
external controller. The transceiver is controlled through
a 4-wire SPI, interrupt (INT/DIO and IRO),
FSK/DATA/FSEL, RCLKOUT/FCAP/FINT and RESET
pins. See Table 2-1 for pin details.
The MRF49XA supports the following feature blocks:
• Clock Generation
• Data Filtering and Amplification
• Data Pattern Recognition and Timing
• Data Processing and Storage
• Independent Transmit and Receiver FIFO Buffers
• Registers
These features reduce the processing load, and hence,
allows the use of low-cost 8-bit microcontrollers for data
processing.
© 2009-2011 Microchip Technology Inc.
Preliminary
DS70590C-page 9