SI4322 Datasheet, PDF (1/22 Pages) Silicon Laboratories – No alignment required in production

Si4322 Universal ISM Band
FSK Receiver
DESCRIPTION
Silicon Labs’s Si4322 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 868 and 915 MHz bands. Used in conjunction with
Silicon Labs’ FSK transmitters, the Si4322 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 is
needed for operation.
The Si4322 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 Si4322 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.
FUNCTIONAL BLOCK DIAGRAM
IN1 13
LNA
IN2 12
MIX
I
AMP OC
MIX
Q
Self cal.
AMP OC
RF Parts
PLL & I/Q VCO
with cal.
RSSI
BB Amp/Filt./Limiter
I/Q
Demod.
clk
Data Filt
CLK Rec ^data
7 DCLK
6 DATA
COMP
DQD
AFC
FIFO
Data processing units
CLK div
8
CLK
Xosc
9
XTL
WTM
with cal.
LBD
Low Power parts
Controller
15
ARSSI
1 2 3 4 5 16 10
SDI SCK nSEL SDO nIRQ VDI nRES
Bias
11 14
VSS VDD
Si4322
PIN ASSIGNMENT
SDI 1
SCK 2
nSEL 3
SDO / FFIT 4
nIRQ 5
DATA / nFFE 6
DCLK / nFFS / CFIL 7
CLK 8
16 VDI
15
11111_I22222_A3333344444₄55555₃66666₂77777₂8888899999
14
13
12
ARSSI
VDD
IN1
IN2
11 VSS
10 nRES
9 XTL / REF
This document refers to Si4322-IC Rev A0.
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
(134 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
• 48 bit RX data FIFO
• Standard 10 MHz crystal reference
• Wake-up timer
• Low battery detector
• 2.2 to 3.8 V supply voltage
• Low power consumption
• Low standby current (typ. 0.3 μA)
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
Si4322-DS rev 1.1r 0308
www.silabs.com