SX1781 Datasheet, PDF (1/16 Pages) Semtech Corporation – PLL Frequency Synthesizer with Integrated VCO

SX1781
PLL Frequency Synthesizer with Integrated VCO
ADVANCED COMMUNICATIONS & SENSING
FINAL
DATASHEET
GENERAL DESCRIPTION
The SX1781 is a high-performance low phase noise
integer-N frequency synthesizer for wireless
communications applications. The circuit embeds a
fully integrated PLL (including VCO tank and loop
filter), complementary output buffers The divider and
power-down settings are programmable via an SPI
interface. A Lock Detector pin linked to a squelch
function have been designed to ease the software
development.
PIN DIAGRAM
FEATURES
Frequency range:1200 to 1400 MHz
Frequency step: 250 kHz min.
Phase noise: -85 dBc/Hz @ 10 kHz offset
Reference spurs: -67 dBc
Hopping time: 350 µs max.
Operating voltage: 3.0 - 3.6V
Programmable Output Power: up to +5 dBm
Integrated VCO and loop filter
SPI-bus interface
Lock Detect output and squelch
Ultra-low power sleep mode
Complementary RF outputs
Temperature range: -40 to +85°C
4 x 4 mm MLPQ16 package
Pb-free and RoHS compliant
ORDERING INFORMATION
Part Number Delivery Quantity
SX1781IMLTRT Tape & Reel 3000 pces
BLOCK DIAGRAM
CSB SCK MOSI MISO
VDDA VDDD VDDF
CLK
÷[RDiv+1]
PFD
Loop
Filter
VCO
÷2
SLEEPB
Rev 1 - November 2008
©2008 Semtech Corp.
÷ [N Div+4800]
VSSA VSSD VSSF
Page 1
Out_P
Out_N
LD
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