Si4320 Universal ISM
Band FSK Receiver
Si4320
PIN ASSIGNMENT
DESCRIPTION
Silicon Labs’ Si4320 is a single chip, low power, multi-channel FSK
receiver designed for use in applications requiring FCC or ETSI
conformance for unlicensed use in the 315, 433, 868, and 915 MHz
bands. Used in conjunction with Si4220/21, Silicon Labs’ FSK
transmitters, the Si4320 is a flexible, low cost, and highly integrated
solution that does not require production alignments. All required RF
functions are integrated. Only an external crystal and bypass filtering are
needed for operation.
The Si4320 has a completely integrated PLL for easy RF design, and its
rapid settling time allows for fast frequency hopping, bypassing multipath
fading, and interference to achieve robust wireless links. The PLL’s high
resolution allows the usage of multiple channels in any of the bands. The
baseband bandwidth (BW) is programmable to accommodate various
deviation, data rate, and crystal tolerance requirements. The receiver
employs the Zero-IF approach with I/Q demodulation, therefore no external
components (except crystal and decoupling) are needed in a typical
application. The Si4320 is a complete analog RF and baseband receiver
including a multi-band PLL synthesizer with an LNA, I/Q down converter
mixers, baseband filters and amplifiers, and I/Q demodulator.
The chip dramatically reduces the load on the microcontroller with
integrated digital data processing: data filtering, clock recovery, data
pattern recognition and integrated FIFO. The automatic frequency control
(AFC) feature allows using a low accuracy (low cost) crystal. To minimize
the system cost, the chip can provide a clock signal for the microcontroller,
avoiding the need for two crystals.
For simple applications, the receiver supports a standalone operation
mode. This allows complete data receiver operation and control of four
digital outputs based on the incoming data pattern without a
microcontroller. In this mode, 12 or more predefined frequency channels
can be used in any of the four bands. For low power applications, the
device supports low duty-cycle operation based on the internal wake-up
timer.
FUNCTIONAL BLOCK DIAGRAM
Standalone Mode
Microcontroller Mode
This document refers to Si4320-IC Rev J1.
See www.silabs.com/integration for any applicable
errata. See back page for ordering information.
FEATURES
Fully integrated (low BOM, easy design-in)
No alignment required in production
Fast settling, programmable, high-resolution PLL
Fast frequency hopping capability
High bit rate (up to 115.2 kbps in digital mode and 256 kbps
in analog mode)
Direct differential antenna input
Programmable baseband bandwidth (67 to 400 kHz)
Analog and digital RSSI outputs
Automatic frequency control (AFC)
Data quality detection (DQD)
Internal data filtering and clock recovery
RX pattern recognition
SPI compatible serial control interface
Clock and reset signals for microcontroller
16 bit RX data FIFO
Standalone operation mode without microcontroller
Low power duty-cycle mode (less than 0.5 mA average
supply current)
Standard 10 MHz crystal reference with in circuit calibration
Alternative OOK support
Wake-up timer
Low battery detector
2.2 to 5.4 V supply voltage
Low power consumption (~9 mA in low bands)
Low standby current (0.3 µA)
Compact 16-pin TSSOP package
TYPICAL APPLICATIONS
Remote control
Home security and alarm
Wireless keyboard/mouse and other PC peripherals
Toy control
Remote keyless entry
Tire pressure monitoring
Telemetry
Personal/patient data logging
Remote automatic meter reading
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Si4320-DS Rev 1.5r 0308
www.silabs.com