LTC5540IUH#PBF

RF Mixers Overview

The LTC5540IUH#PBF is a high dynamic range passive down-converting mixer from Analog Devices, optimized for RF frequencies between 600MHz and 1.3GHz with LO inputs ranging from 700MHz to 1.2GHz. Designed for 3.3V operation, it delivers a typical conversion gain of 7.9dB at 900MHz, an IIP3 of 25.9dBm, and a noise figure of 9.9dB. The device features an integrated SPDT LO switch, 50Ω single-ended RF and LO inputs, and a shutdown pin. It is housed in a compact 20-lead QFN (5mm x 5mm) package with an exposed pad.

RF Mixers Feature Summary

• Integrated SPDT LO switch accepting two active LO signals for high isolation
• High conversion gain and dynamic range enabling relaxed IF filter specifications
• Optimized for 3.3V supply with separate 5V capability for IF amplifier biasing
• 50Ω matched single-ended inputs for simplified circuit design

RF Mixers Applications

• LTE and GSM receiver front-ends
• Wireless infrastructure receivers
• Point-to-point microwave link systems

RF Mixers Procurement Notes

Verify the specific suffix (#PBF indicates tube packaging) against current distributor availability, as this part number may be subject to restricted availability or limited stock conditions. Confirm that the 20-pin QFN EP package matches your PCB footprint requirements. Ensure the 3.3V core voltage and optional 5V IF supply align with your system power architecture before finalizing procurement.

RF Mixers Selection Notes

Select this component when designing receivers requiring high linearity and low noise within the 600MHz to 1.3GHz band. The integrated LO switch simplifies designs needing dual-source LO switching without external components. Consider the 7.9dB gain for potential LNA reduction. Verify thermal performance due to the exposed pad requirement and ensure the 50Ω input matching network supports the specified frequency ranges for optimal P1dB and IIP3 performance.

RF Mixers Part Context

The LTC5540IUH#PBF belongs to a family of high dynamic range passive mixers covering 600MHz to 4GHz. It is specifically optimized for lower UHF bands compared to siblings like the LTC5541 or LTC5542. The #PBF suffix denotes tube packaging, distinct from the #TRPBF tape-and-reel variant. It serves as a key building block for modern cellular base station and mobile device receiver architectures.

RF Mixers Replacement Considerations

For direct functional replacements within the same Analog Devices portfolio, consider the LTC5540IUH#TRPBF for identical electrical characteristics but different packaging. For broader frequency coverage, evaluate the LTC5541 (1.3GHz–2.3GHz RF) or LTC5542 (1.6GHz–2.7GHz RF). Cross-vendor substitutes require careful re-evaluation of linearity and noise parameters.

RF Mixers FAQ

Can the IF amplifier section operate on a voltage other than 3.3V?

Yes, while the core device operates at 3.3V, the IF amplifier can be powered by a 5V supply to achieve higher P1dB performance.

What is the purpose of the integrated SPDT LO switch?

It allows the mixer to accept two active LO signals simultaneously, providing high isolation between the sources and enabling fast switching operations.