PLL Frequency Synthesizer
Semtech SX1781

Semtech SX1781

PLL Frequency Synthesizer with Integrated VCO

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Not Recommended for New Designs. Please contact your local Semtech sales representative.


  • 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 ms 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


  • Wireless Communications Applications
  • Wireless Industrial Applications
  • Automatic Meter Reading
  • Good replacement for discrete PLL Designs


MLPQ16 (4mm x 4mm)

Order Codes

  • SX1781IMLTRT: Lead-Free and RoHS Compliant, 3000 pcs Tape and Reel
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