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LMX2491

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6.4-GHz low noise fractional-N PLL with ramp/chirp generation

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Data sheet

LMX2491

ACTIVE
Data sheet Order now

Product details

Integrated VCO No Output frequency (min) (MHz) 500 Output frequency (max) (MHz) 6400 Normalized PLL phase noise (dBc/Hz) -227 Current consumption (mA) 60 Features Flexible ramp generation, Wideband 1/f noise (10-kHz offset at 1-GHz carrier) (dBc/Hz) -120 Rating Catalog Operating temperature range (°C) -40 to 85 Lock time (µs) (typ) Loop BW dependent
Integrated VCO No Output frequency (min) (MHz) 500 Output frequency (max) (MHz) 6400 Normalized PLL phase noise (dBc/Hz) -227 Current consumption (mA) 60 Features Flexible ramp generation, Wideband 1/f noise (10-kHz offset at 1-GHz carrier) (dBc/Hz) -120 Rating Catalog Operating temperature range (°C) -40 to 85 Lock time (µs) (typ) Loop BW dependent
WQFN (RTW) 24 16 mm² 4 x 4
  • –227-dBc/Hz Normalized PLL Noise
  • 500-MHz to 6.4-GHz Wideband PLL
  • 3.15-V to 5.25-V Charge Pump PLL Supply
  • Versatile Ramp / Chirp Generation
  • 200-MHz Maximum Phase Detector Frequency
  • FSK / PSK Modulation Pin
  • Digital Lock Detect
  • Single 3.3-V Supply Capability
  • –227-dBc/Hz Normalized PLL Noise
  • 500-MHz to 6.4-GHz Wideband PLL
  • 3.15-V to 5.25-V Charge Pump PLL Supply
  • Versatile Ramp / Chirp Generation
  • 200-MHz Maximum Phase Detector Frequency
  • FSK / PSK Modulation Pin
  • Digital Lock Detect
  • Single 3.3-V Supply Capability

The LMX2491 device is a low-noise, 6.4-GHz wideband delta-sigma fractional N PLL with ramp and chirp generation. It consists of a phase frequency detector, programmable charge pump, and high frequency input for the external VCO. The LMX2491 supports a broad and flexible class of ramping capabilities, including FSK, PSK, and configurable piecewise linear FM modulation profiles of up to 8 segments. It supports fine PLL resolution and fast ramp with up to a 200-MHz phase detector rate. The LMX2491 allows any of its registers to be read back. The LMX2491 can operate with a single 3.3-V supply. Moreover, supporting up to 5.25-V charge pump can eliminate the need of external amplifier, leading to a simpler solution with improved phase noise performance.

The LMX2491 device is a low-noise, 6.4-GHz wideband delta-sigma fractional N PLL with ramp and chirp generation. It consists of a phase frequency detector, programmable charge pump, and high frequency input for the external VCO. The LMX2491 supports a broad and flexible class of ramping capabilities, including FSK, PSK, and configurable piecewise linear FM modulation profiles of up to 8 segments. It supports fine PLL resolution and fast ramp with up to a 200-MHz phase detector rate. The LMX2491 allows any of its registers to be read back. The LMX2491 can operate with a single 3.3-V supply. Moreover, supporting up to 5.25-V charge pump can eliminate the need of external amplifier, leading to a simpler solution with improved phase noise performance.
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* Data sheet LMX2491 6.4-GHz Low Noise RF PLL With Ramp/Chirp Generation datasheet (Rev. A) PDF | HTML 23 Jan 2017

Design & development

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

Evaluation board

LMX2492EVM — LMX2492 Evaluation Module

The LMX2492EVM supports evaluation of the LMX2492 and LMX2492-Q1 which is an ultra-low noise 14 GHz wideband RF PLL with ramp/chirp generation, consisting of a delta-sigma fractional N PLL, phase detector, programmable 5V charge pump and high frequency divider for the VCO. The LMX2492 supports a (...)

User guide: PDF
Not available on TI.com
Evaluation board

XMICR-3P-LMX2492 — LMX2492 X-MWblock evaluation modules

X-MWblocks consist of RF and Microwave “Drop-In” components that can be used individually for prototyping or in production assemblies. X-MWblocks are easy to test, integrate, align, and configure to 60 GHz and beyond. No messy Sweat Soldering or Silver Epoxy processes are required. X-MWblocks are (...)

From: X-Microwave
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Support software

TICSPRO-SW — TICS Pro v1.7.5.15, 30-Jun-2023

Texas Instruments clocks and synthesizers (TICS) pro software is used to program the evaluation modules (EVMs) for product numbers with these prefixes: CDC, LMK and LMX. These products include phase-locked loops and voltage-controlled oscillators (PLL+VCO), synthesizers and clocking devices.

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Supported products & hardware

Supported products & hardware

Products
Clock generators
CDCE6214-Q1 — Ultra-low power clock generator supporting PCIe gen 1-5 with 2 inputs, 4 outputs and internal EEPROM CDCI6214 — PCIe Gen4 support ultra-low power clock generator with four programmable outputs & EEPROM LMK02000 — 1 to 800-MHz, precision clock distributor with integrated PLL and 3 LVDS / 5 LVPECL outputs LMK02002 — 1 to 800-MHz, precision clock distributor with integrated PLL and 4 LVPECL outputs LMK03200 — Precision 0-delay clock conditioner with integrated VCO LMK03318 — Ultra-low jitter clock generator family with single PLL LMK03328 — Ultra-low jitter clock generator family with two independent PLLs LMK03806 — Ultra-low jitter clock generator with 14 outputs
RF PLLs & synthesizers
LMX1204 — 12.8-GHz RF buffer, multiplier and divider with JESD204B/C SYSREF support and phase synchronization LMX2485 — 500-MHz to 3-GHz delta-sigma low power dual PLL for RF personal communications LMX2485E — 50-MHz to 3-GHz delta-sigma low power dual PLL for RF personal communications LMX2485Q-Q1 — 500MHz to 3GHz automotive delta-sigma low power dual PLL LMX2486 — 1-GHz to 4.5-GHz delta-sigma low power dual PLL for RF personal communications LMX2487 — 1 to 6-GHz delta-sigma low power dual PLLatinum frequency synthesizer with 3.0-GHz integer PLL LMX2487E — 3-GHz to 7.5-GHz delta-sigma low power dual PLL for RF personal communications LMX2491 — 6.4-GHz low noise fractional-N PLL with ramp/chirp generation LMX2492 — 500MHz to 14GHz wideband, low noise fractional-N PLL with ramp/chirp generation LMX2492-Q1 — Automotive grade 500-MHz to 14-GHz wideband, low noise fractional-N PLL with ramp/chirp generation LMX2531 — High performance frequency synthesizer system with integrated VCO LMX2541 — Ultra-low noise PLLatinum frequency synthesizer with integrated VCO LMX2571 — 1.34-GHz, low-power, extreme-temperature RF synthesizer with frequency-shift keying (FSK) modulation LMX2571-EP — Enhanced-product, 1.34-GHz, low-power, extreme-temperature RF synthesizer with FSK modulation LMX2572 — 6.4-GHz low-power wideband RF synthesizer LMX2572LP — 2-GHz low power wideband RF synthesizer with FSK modulation LMX2581 — 3.76-GHz wideband frequency synthesizer with integrated VCO LMX2581E — 3.8-GHz wideband frequency synthesizer with integrated VCO LMX2582 — 5.5-GHz high performance, wideband PLLatinum RF synthesizer LMX2592 — 9.8-GHz wideband frequency synthesizer with integrated VCO LMX2594 — 15-GHz wideband PLLatinum™ RF synthesizer with phase synchronization and JESD204B support LMX2595 — 20-GHz wideband RF synthesizer with phase synchronization & JESD204B support LMX2820 — 22.6-GHz wideband RF synthesizer with phase synchronization, JESD and <5-µs frequency calibration
Clock jitter cleaners & synchronizers
LMK04100 — Precision clock conditioners clock jitter cleaner with cascaded PLLs LMK04101 — Jitter cleaner with integrated 1430 to 1570-MHz VCO:3 outputs for 2VPEC/LVPEC+4 outputs for LVCOMS LMK04102 — Jitter cleaner with integrated 1600 to 1750-MHz VCO:3 outputs for 2VPEC/LVPEC+4 outputs for LVCOMS LMK04110 — Jitter cleaner with integrated 1185 to 1296-MHz VCO:5 outputs for 2VPEC/LVPEC LMK04111 — Jitter cleaner with integrated 1430 to 1570-MHz VCO:5 outputs for 2VPEC/LVPEC LMK04131 — Jitter cleaner with integrated 1430 to 1570-MHz VCO:2 outputs for 2VPEC/LVPEC+LVDS+LVCOMS LMK04133 — Jitter cleaner with integrated 1840 to 2160-MHz VCO:2 outputs for 2VPEC/LVPEC+LVDS+LVCOMS LMK04208 — Ultra low-noise clock jitter cleaner with 6 programmable outputs LMK04228 — Ultra low-noise clock jitter cleaner with dual loop PLLs LMK04610 — Ultra low-noise and low power JESD204B compliant clock jitter cleaner with dual PLLs LMK04616 — Ultra low-noise and low power JESD204B compliant clock jitter cleaner LMK04803 — Low-noise clock jitter cleaner with dual cascaded PLLs and integrated 1.9-GHz VCO LMK04816 — Three input low-noise clock jitter cleaner with dual loop PLLs LMK04821 — Ultra low jitter synthesizer and jitter cleaner with JESD204B support LMK04826 — Ultra low-noise JESD204B compliant clock jitter cleaner with integrated 1840 to1970-MHz VCO0 LMK04828 — Ultra low-noise JESD204B compliant clock jitter cleaner with integrated 2370 to 2630-MHz VCO0. LMK04828-EP — Ultra low-noise JESD204B compliant clock jitter cleaner with temperature range -55 to 105c LMK04832 — Ultra-low-noise, 3.2-GHz, 15-output, JESD204B clock jitter cleaner with dual loop LMK04832-SEP — Radiation-tolerant, 30-krad, ultra-low-noise, 3.2-GHz 15-output JESD204C clock jitter cleaner LMK04832-SP — Radiation-hardened-assured (RHA), ultra-low-noise, 3.2-GHz, 15-output clock jitter cleaner LMK05028 — Low-jitter dual-channel network synchronizer clock LMK05318 — Ultra-low jitter single channel network synchronizer clock with BAW LMK05318B — Ultra-low jitter single channel network synchronizer clock with BAW LMK5B12204 — Ultra-low jitter clock generator with network synchronization and BAW technology LMK5B33216 — 16-output, three DPLL and APLL, network synchronizer with integrated 2.5-GHz bulk-acoustic-wave VCO LMK5B33414 — 14-output, three DPLL and APLL, network synchronizer with integrated 2.5-GHz bulk-acoustic-wave VCO LMK5C33216 — Ultra-low jitter clock synchronizer with JESD204B for wireless communications with BAW
Clock buffers
CDCDB800 — 8-output clock buffer for PCIe® Gen 1 to Gen 6 LMK01000 — 1.6-GHz high performance clock buffer, divider, and distributor with 3 LVDS & 5 LVPECL outputs LMK01010 — 1.6-GHz high performance clock buffer, divider, and distributor with 8 LVDS outputs LMK01020 — 1.6-GHz high performance clock buffer, divider, and distributor with 8 LVPECL outputs LMK01801 — Dual clock distribution LMK1D1208I — 8-channel output, 1.8-V, 2.5-V, and 3.3-V LVDS buffer with I²C
Hardware development
Evaluation board
LMK03806BEVAL — LMK03806B Evaluation Board LMK04208EVM — Two Input, 6+1 Output, Clock Jitter Cleaner With Dual Cascaded PLLs and Integrated 2.9 GHz VCO LMK04616EVM — LMK04616 Evaluation Module LMK04803BEVAL — Clock Jitter Cleaner With Dual Cascaded PLLs and Integrated 1.9 GHz VCO LMK04805BEVAL — Clock Jitter Cleaner With Dual Cascaded PLLs and Integrated 2.2 GHz VCO LMK04806BEVAL — Clock Jitter Cleaner With Dual Cascaded PLLs and Integrated 2.5 GHz VCO LMK04808BEVAL — Clock Jitter Cleaner With Dual Cascaded PLLs and Integrated 2.9 GHz VCO LMK04816BEVAL — Three Input, Thirteen Output, Clock Jitter Cleaner with Dual Cascaded PLLs and Integrated 2.5 GHz VC LMK04826BEVM — LMK04826BEVM Evaluation Module LMK04828BEVM — LMK04828 evaluation module LMK04832EVM — LMK04832 JESD204B Clock Jitter Cleaner/Clock Generator/Distribution Evaluation Module LMK04832SEPEVM — LMK04832-SEP evaluation module for ultra-low-noise, 3.2-GHz 15-output clock jitter clea LMK04906BEVAL — Three Input, Seven Output, Clock Jitter Cleaner with Dual Cascaded PLLs and Integrated 2.5 GHz VCO LMK5B33216EVM — LMK5B33216 evaluation module for 16-output, three DPLL and APLL, network synchronizer with BAW VCO LMX2571EPEVM — LMX2571-EP evaluation module for 1.34-GHz, low-power, extreme-temperature RF synthesizer LMX2582EVM — LMX2582EVM High Performance, Wideband Frequency PLLatinum RF Synthesizer With Integrated VCO LMX2592EVM — LMX2592EVM high-performance, wideband frequency RF synthesizer PLLATINUM™ integrated circuit LMX2594PSEVM — LMX2594 evaluation module for 15-GHz RF synthesizer with multiple-device phase synchronization XMICR-3P-LMX2492 — LMX2492 X-MWblock evaluation modules XMICR-3P-LMX2572 — LMX2572 X-MWblock evaluation modules XMICR-3P-LMX2592 — LMX2592 X-MWblock evaluation modules XMICR-3P-LMX2594 — LMX2594 X-MWblock evaluation modules XMICR-3P-LMX2595 — LMX2595 X-MWblock evaluation modules
Software
Application software & framework
TICSPRO-SW — Texas Instruments Clocks and Synthesizers (TICS) Pro Software
IDE, configuration, compiler or debugger
CODELOADER — CodeLoader Software for device register programming
lock Download
Design tool

CLOCK-TREE-ARCHITECT — Clock tree architect programming software

Clock tree architect is a clock tree synthesis tool that streamlines your design process by generating clock tree solutions based on your system requirements. The tool pulls data from an extensive database of clocking products to generate a system-level multi-chip clocking solution.
Design now
Design tool

PLLATINUMSIM-SW — PLLatinum Sim Tool

PLLATINUMSIM-SW is a simulation tool that allows users to create detailed designs and simulations of our PLLatinum™ integrated circuits, which include the LMX series of phase-locked loops (PLLs) and synthesizers.

lock = Requires export approval (1 minute)
Supported products & hardware

Supported products & hardware

Products
RF PLLs & synthesizers
LMX1204 — 12.8-GHz RF buffer, multiplier and divider with JESD204B/C SYSREF support and phase synchronization LMX2430 — 3.0-GHz/0.8-GHz PLLatinum dual high frequency synthesizer for RF personal communications LMX2433 — 3.6-GHz/1.7-GHz PLLatinum dual high frequency synthesizer for RF personal communications LMX2434 — 5.0-GHz/2.5-GHz PLLatinum low power dual frequency synthesizer for RF personal communications LMX2470 — 2.6-GHz delta-sigma fractional-N PLL with 800-MHz integer-N PLL LMX2485 — 500-MHz to 3-GHz delta-sigma low power dual PLL for RF personal communications LMX2485E — 50-MHz to 3-GHz delta-sigma low power dual PLL for RF personal communications LMX2485Q-Q1 — 500MHz to 3GHz automotive delta-sigma low power dual PLL LMX2486 — 1-GHz to 4.5-GHz delta-sigma low power dual PLL for RF personal communications LMX2487 — 1 to 6-GHz delta-sigma low power dual PLLatinum frequency synthesizer with 3.0-GHz integer PLL LMX2487E — 3-GHz to 7.5-GHz delta-sigma low power dual PLL for RF personal communications LMX2491 — 6.4-GHz low noise fractional-N PLL with ramp/chirp generation LMX2492 — 500MHz to 14GHz wideband, low noise fractional-N PLL with ramp/chirp generation LMX2492-Q1 — Automotive grade 500-MHz to 14-GHz wideband, low noise fractional-N PLL with ramp/chirp generation LMX2531 — High performance frequency synthesizer system with integrated VCO LMX2541 — Ultra-low noise PLLatinum frequency synthesizer with integrated VCO LMX2571 — 1.34-GHz, low-power, extreme-temperature RF synthesizer with frequency-shift keying (FSK) modulation LMX2571-EP — Enhanced-product, 1.34-GHz, low-power, extreme-temperature RF synthesizer with FSK modulation LMX2572 — 6.4-GHz low-power wideband RF synthesizer LMX2572LP — 2-GHz low power wideband RF synthesizer with FSK modulation LMX2581 — 3.76-GHz wideband frequency synthesizer with integrated VCO LMX2581E — 3.8-GHz wideband frequency synthesizer with integrated VCO LMX2582 — 5.5-GHz high performance, wideband PLLatinum RF synthesizer LMX2592 — 9.8-GHz wideband frequency synthesizer with integrated VCO LMX2594 — 15-GHz wideband PLLatinum™ RF synthesizer with phase synchronization and JESD204B support LMX2595 — 20-GHz wideband RF synthesizer with phase synchronization & JESD204B support
Clock jitter cleaners & synchronizers
LMK04828 — Ultra low-noise JESD204B compliant clock jitter cleaner with integrated 2370 to 2630-MHz VCO0. LMK04832 — Ultra-low-noise, 3.2-GHz, 15-output, JESD204B clock jitter cleaner with dual loop LMK04832-SEP — Radiation-tolerant, 30-krad, ultra-low-noise, 3.2-GHz 15-output JESD204C clock jitter cleaner LMK5B33216 — 16-output, three DPLL and APLL, network synchronizer with integrated 2.5-GHz bulk-acoustic-wave VCO LMK5B33414 — 14-output, three DPLL and APLL, network synchronizer with integrated 2.5-GHz bulk-acoustic-wave VCO
Hardware development
Evaluation board
LMK04832EVM — LMK04832 JESD204B Clock Jitter Cleaner/Clock Generator/Distribution Evaluation Module LMX2571EPEVM — LMX2571-EP evaluation module for 1.34-GHz, low-power, extreme-temperature RF synthesizer LMX2594PSEVM — LMX2594 evaluation module for 15-GHz RF synthesizer with multiple-device phase synchronization XMICR-3P-LMX2492 — LMX2492 X-MWblock evaluation modules XMICR-3P-LMX2572 — LMX2572 X-MWblock evaluation modules XMICR-3P-LMX2592 — LMX2592 X-MWblock evaluation modules XMICR-3P-LMX2594 — LMX2594 X-MWblock evaluation modules XMICR-3P-LMX2595 — LMX2595 X-MWblock evaluation modules
Software
Application software & framework
PLLATINUMSIM-SW — Texas Instruments PLLatinum Simulator Tool TICSPRO-SW — Texas Instruments Clocks and Synthesizers (TICS) Pro Software
IDE, configuration, compiler or debugger
CODELOADER — CodeLoader Software for device register programming
lock Download
Package Pins Download
WQFN (RTW) 24 View options
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