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Product details

Parameters

Integrated VCO No Output frequency (Min) (MHz) 500 Output frequency (Max) (MHz) 3100 Normalized PLL phase noise (dBc/Hz) -210 Current consumption (mA) 5 1/f noise (10-kHz offset at 1-GHz carrier) (dBc/Hz) -104 open-in-new Find other RF PLLs & synthesizers

Package | Pins | Size

WQFN (RTW) 24 16 mm² 4 x 4 open-in-new Find other RF PLLs & synthesizers

Features

  • Quadruple Modulus Prescaler for Lower Divides
    • RF PLL: 8/9/12/13 or 16/17/20/21
    • IF PLL: 8/9 or 16/17
  • Advanced Delta Sigma Fractional Compensation
    • 12-Bit or 22-Bit Selectable Fractional Modulus
    • Up to 4th Order Programmable Delta-Sigma
      Modulator
  • Improved Lock Times and Programming
    • Fastlock / Cycle Slip Reduction Requiring Only
      a Single-Word Write
    • Integrated Time-Out Counter
  • Wide Operating Range
    • LMX2485Q-Q1 RF PLL: 500 MHz to 3.1 GHz
  • Useful Features
    • Digital Lock Detect Output
    • Hardware and Software Power-Down Control
    • On-Chip Input Frequency Doubler
    • RF Phase Detector Frequency Up to 50 MHz
    • 2.5-V to 3.6-V Operation With ICC = 5.0 mA
    • LMX2485Q-Q1 is AEC-Q100 Grade 2
      Qualified and is Manufactured on an
      Automotive Grade Flow
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Description

The LMX2485Q-Q1 is a low power, high performance delta-sigma fractional-N PLL with an auxiliary integer-N PLL. The device is fabricated using TI’s advanced process.

With delta-sigma architecture, fractional spurs at lower offset frequencies are pushed to higher frequencies outside the loop bandwidth. The ability to push close in spur and phase noise energy to higher frequencies is a direct function of the modulator order. Unlike analog compensation, the digital feedback technique used in the LMX2485Q-Q1 is highly resistant to changes in temperature and variations in wafer processing. The LMX2485Q-Q1 delta-sigma modulator is programmable up to fourth order, which allows the designer to select the optimum modulator order to fit the phase noise, spur, and lock time requirements of the system.

Serial data for programming the LMX2485Q-Q1 is transferred through a three-line, high-speed (20-MHz) MICROWIRE interface. The LMX2485Q-Q1 offers fine frequency resolution, low spurs, fast programming speed, and a single word write to change the frequency. This makes it ideal for direct digital modulation applications, where the N-counter is directly modulated with information. The LMX2485Q-Q1 is available in a 24-lead 4.0 × 4.0 × 0.8 mm WQFN package.

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Technical documentation

= Top documentation for this product selected by TI
No results found. Please clear your search and try again. View all 3
Type Title Date
* Datasheet LMX2485Q-Q1 500 MHz - 3.1 GHz High Performance Delta-Sigma Low Power Dual PLLatinum Frequency Synthesizers With 800-MHz Integer PLL datasheet (Rev. A) Jan. 13, 2016
User guides LMX248x Evaluation Board User's Guide (Rev. B) Jul. 27, 2018
Application notes AN-1879 Fractional N Frequency Synthesis (Rev. A) Apr. 26, 2013

Design & development

For additional terms or required resources, click any title below to view the detail page where available.

Software development

APPLICATION SOFTWARE & FRAMEWORKS Download
Clock Design Tool - Loop Filter & Device Configuration + Simulation
CLOCKDESIGNTOOL The Clock Design Tool software helps with part selection, loop filter design and simulation of timing device solutions. When you enter desired output frequencies and a reference frequency (optional), the tool provides TI devices to meet the specified requirements, divider values and a recommended (...)
APPLICATION SOFTWARE & FRAMEWORKS Download
Texas Instruments PLLatinum Simulator Tool
PLLATINUMSIM-SW The PLLATINUMSIM-SW simulator tool lets you create detailed designs and simulations of our PLLATINUM™ integrated circuits which include the LMX series of PLLs and synthesizers.
Features
  • Part selection based on current, cost, phase noise and package
  • Filter design up for passive and active filters up to 4th-order
  • Simulation of phase noise including PLL, fractional engine, voltage-controlled oscillator (VCO), input, dividers, and loop filter
  • Simulation of spurs including phase detector (...)
APPLICATION SOFTWARE & FRAMEWORKS Download
Texas Instruments Clocks and Synthesizers (TICS) Pro Software
TICSPRO-SW The TICS Pro software is used to program the evaluation modules (EVMs) for device numbers with these prefixes: CDC, LMK and LMX. These devices include PLLs and voltage-controlled oscillators (PLL+VCO), synthesizers and clocking devices.
Features
  • Program EVMs through the USB2ANY Interface Adaptor or onboard USB interface.
  • Export programming configurations for use in end application.
IDES, CONFIGURATION, COMPILERS & DEBUGGERS Download
CodeLoader Software for device register programming
CODELOADER The CodeLoader 4 software is used to program the LMX PLLs and LMK timing devices through either the USB or line print terminal (LPT) port of a computer. This software also provides information on how to program the device by showing the bits that are actually sent.


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Package Pins Download
WQFN (RTW) 24 View options

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