Date: 21/07/2009

New upconverting Mixer from Linear supporting full range of LTE services

The LT5578 upconverting mixer from Linear Technology delivers high dynamic range in the frequency range of 400MHz to 2.7GHz, supporting all of the allocated LTE (Long-Term Evolution) broadband wireless services.

The features of the device are:

At 900MHz, the mixer offers 27dBm Output IP3 linearity and best-in-class noise floor of -160.5dBm/Hz at an output level of -5dBm.
The mixer has 1.4dB conversion gain with integrated RF balun transformers that provide a single-ended RF output and LO (Local Oscillator) input.
LO input is internally buffered, requiring a drive level of only -1dBm. This results in an outstanding LO-to-RF leakage of -43dBm.
The LT5578 operates from a single 3.3V supply.
Typical quiescent supply current is 152mA.

LT5578 is suitable for next generation LTE wireless basestation transmitters and improves the performance of wireless equipment including W-CDMA / UMTS, TD-SCDMA, CDMA2000, CDMA, and GSM/EDGE basestations. The mixer is also suggested for a wide range of communications gear such as cable headend transmitters, microwave broadband transmitters, wireless repeaters, military radios, digital video broadcast systems, 2.4GHz ISM band transmitters, test instrumentation, micro-cell and pico-cell basestation applications.

Linear says the LT5578's active, double-balanced design provides several unique benefits. Compared to alternative passive mixers' more than 8dB of conversion loss, the LT5578's 1.4dB conversion gain produces 9dB higher signal power without the need of an external high power, high linearity RF output amplifier stage. Most passive mixers have poor port-to-port isolation, resulting in undesirable leakage of the LO signal to the RF output, which necessitates a high rejection RF filter for suppression. The LT5578's balanced design inherently suppresses the LO-to-RF leakage to -43dBm typical, thus relaxing and reducing external filtering requirements.

Package: 24-lead 5mm x 5mm plastic QFN surface mount package.

Price: Each $5.25 for 1k pieces.

For more details visit www.linear.com.