LMX2491RTWR

Clock Generators, PLLs, Frequency Synthesizers Overview

The LMX2491RTWR is a broadband fractional-N phase-locked loop (PLL) frequency synthesizer manufactured by Texas Instruments. It operates with an input frequency range of 500 MHz to 6.4 GHz and provides an output frequency range starting from 200 MHz. The device utilizes Silicon technology and features a single circuit configuration housed in a 24-pin WQFN package with an exposed pad, designed for surface-mount installation. It supports a supply voltage between 3.15 V and 3.45 V and functions within a temperature range of -40°C to +85°C. Key electrical specifications include a maximum input frequency of 6.4 GHz and a minimum input frequency of 500 MHz.

Clock Generators, PLLs, Frequency Synthesizers Feature Summary

• Integrated ramp and chirp generation capabilities for direct control of external voltage-controlled oscillators (VCOs).
• Supports multiple modulation schemes including Frequency Shift Keying (FSK) and Phase Shift Keying (PSK).
• Configurable segmented linear FM modulation profiles allowing up to eight distinct segments.
• High phase detector frequency enabling rapid slew rates and fine frequency resolution.

Clock Generators, PLLs, Frequency Synthesizers Applications

• Frequency Modulated Continuous Wave (FMCW) radar systems and microwave ranging applications.
• Local oscillator synthesis for point-to-point microwave communication links.
• Signal generation for high-precision test and measurement instruments such as spectrum analyzers.
• Base station and VSAT satellite communication infrastructure requiring low phase noise.

Clock Generators, PLLs, Frequency Synthesizers Procurement Notes

Verify the specific suffix 'R' indicates tape-and-reel packaging when sourcing components. Confirm RoHS compliance status through official manufacturer documentation prior to integration. Ensure the operating environment remains within the specified -40°C to +85°C thermal limits. Validate that the 3.15 V to 3.45 V power supply constraints are strictly maintained during system design.

Clock Generators, PLLs, Frequency Synthesizers Selection Notes

Select this component for designs requiring a single PLL with integrated ramp generation up to 6.4 GHz. Consider the LMX2492 if higher output frequencies up to 14 GHz are necessary. Evaluate the LMX2485E if dual PLL functionality or lower frequency ranges better suit the application requirements. Ensure the 24-WQFN footprint aligns with the PCB layout constraints.

Clock Generators, PLLs, Frequency Synthesizers Part Context

This part belongs to the LMX249x series of low-noise fractional-N PLLs from Texas Instruments. It shares architectural similarities with the LMX2492 but offers a reduced maximum output frequency of 6.4 GHz compared to the 14 GHz capability of its sibling. The RTWR designation specifically identifies the commercial grade variant in a reel-packaged WQFN-24 form factor.

Clock Generators, PLLs, Frequency Synthesizers Replacement Considerations

LMX2492RTWR: Offers extended frequency range up to 14 GHz with similar ramp generation features.

Clock Generators, PLLs, Frequency Synthesizers FAQ

Does the ramp function generate a time-varying frequency waveform?

Yes, the internal ramp generator produces a voltage waveform used to control an external VCO, resulting in a linear frequency modulation signal over time.

What is the maximum supported phase detector frequency?

The device supports a phase detector frequency of up to 200 MHz, which facilitates fast settling times and precise frequency steps.

Can the LMX2491RTWR operate without an external VCO?

No, the LMX2491RTWR is a frequency synthesizer controller that requires an external Voltage-Controlled Oscillator (VCO) to generate the final RF output signal.