LMX2531 - High Performance Frequency Synthesizer System with Integrated VCO

The LMX2531 is a low-power, high-performance frequency synthesizer system which includes a fully integrated delta-sigma PLL and VCO with fully integrated tank circuit. The third and fourth poles are also integrated and adjustable. Ultra-low noise and high-precision LDOs are integrated for the PLL and VCO, which yield higher supply-noise immunity and more consistent performance. When combined with a high-quality reference oscillator, the LMX2531 device generates very stable, low-noise local-oscillator signals for up and down conversion in wireless communication devices. The LMX2531 device is a monolithic integrated circuit, fabricated in an advanced BiCMOS process. Several different versions of this product accommodate different frequency bands.

• Multiple Frequency Options Available
  • See Device Information Table
  • Frequencies From: 553 MHz to 3132 MHz
• PLL Features
  • Fractional-N Delta-Sigma Modulator Order
    Programmable up to Fourth Order
  • FastLock/Cycle Slip Reduction with Timeout
    Counter
  • Partially Integrated, Adjustable Loop Filter
  • Very Low Phase Noise and Spurs
• VCO Features
  • Integrated Tank Inductor
  • Low Phase Noise
• Other Features
  • 2.8-V to 3.2-V Operation
  • Low Operating Current
  • Low Power-Down Current
  • 1.8-V MICROWIRE Support
  • 36-Pin 6-mm × 6-mm × 0.8-mm WQFN Package