Upconverting Mixers integrate RF transformer.

Press Release Summary:




Model LT5519 operates over 0.7-1.4 GHz range, while Model LT5520 covers 1.3-2.3 GHz frequency bands without external matching components. On-chip RF transformer enables single-ended output operation for both units. RF port is internally 50 Ohm-matched over full operating frequency range. Built-in LO amplifiers eliminate need for external LO buffers. Operating from 5 V supply, mixers typically draw 60 mA. They come in 4 x 4 mm, 16-lead plastic QFN surface-mount package.



Original Press Release:



High Linearity Active Upconverting Mixers Integrate RF Transformer to Ease RF Design



MILPITAS, CA - April 13, 2004 - Two new high linearity upconverting RF active mixers with integrated RF transformers from Linear Technology deliver superior performance, linearity and low power consumption. The LT5519 and LT5520 active mixers provide the ideal combination of low distortion, low LO (Local Oscillator) drive requirement, high port-to-port isolation, low conversion loss, and ease of use. The LT5519 operates over the 0.7GHz to 1.4GHz range, while the LT5520 covers the 1.3GHz to 2.3GHz frequency bands without requiring external matching components. Moreover, their single-ended operation makes the design task easier. These devices respond to the performance demands of the wireless infrastructure market, and have applications in cellular basestations, cable modem and video-on-demand headend equipment and high performance satellite transceivers.

An RF output transformer is integrated on-chip to enable single-ended output operation for both the LT5519 and LT5520. The RF port is internally 50-Ohm matched over the devices' full operating frequency range, so that no external frequency matching components are typically required. This makes the system designer's task easier, and enhances the repeatable performance and manufacturability of the end products.

The LT5519 and LT5520 have built-in LO amplifiers, eliminating the need for external LO buffers. The LO port is also designed for single-ended drive, and is internally 50-Ohm matched, requiring no external matching components. When used in a radio transmitter, the devices' exceptionally high LO to RF port-to-port isolation greatly reduces the LO leakage to the RF output, which can cause severe interference to radio equipment in other frequency bands and non-compliance with regulatory emission requirements. As a result, the total solution minimizes costly RF filtering, reduces external components, and significantly lowers the overall cost.

The LT5519 and LT5520 operate from a single 5V supply. They typically draw 60mA of current when operating, while consuming only one microampere when in shutdown mode. The LT5519 and LT5520 are offered in a small 4mm x 4mm 16-lead plastic QFN surface mount package. Pricing starts at $4.15 each in 1,000-piece quantities.

Summary of features: LT5519 & LT5520
LT5519 LT5520
Operating Frequency Range 700MHz to 1.4GHz 1.3GHz to 2.3GHz
Input IP3 + 17.1 dBm + 15.9 dBm
LO Drive Level -5 dBm -5dBm
LO-to-RF Leakage -44 dBm -41dBm
Conversion Gain -0.6 dB -1 dB


Company Background
Linear Technology Corporation was founded in 1981 as a manufacturer of high performance linear integrated circuits. Linear Technology products include operational, instrumentation and audio amplifiers; voltage regulators,power management devices, DC-DC converters and voltage references; comparators; monolithic filters; communications interface circuits; one-chip data acquisition sub-systems; pulse-width modulators and sample-and-hold devices; and high frequencydevices. Applications for Linear Technology's high performance circuits include wireless and broadband telecommunications infrastructure, cellular telephones, networking products and satellite systems, notebook and desk top computers, computer peripherals, video/multimedia, industrial and medical instrumentation, automotive electronics, factory automation, process control, military and space systems, and high-end consumer products including digital cameras, MP3 players and other electronic products.

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