Demodulators suit high linearity applications.

Press Release Summary:

Models LT5515 and LT5516 Direct Conversion Quadrature Demodulators integrate signal splitter, 2 high linearity down-converting mixers, local oscillator quadrature generator, and 260 MHz bandwidth output buffers with single-pole, low pass filters on each output. Model LT5515 operates over input frequency of 1.5-2.5 GHz, and Model LT5516 operates with RF input from 0.8-1.5 GHz. Units simplify design for cellular basestations and microwave satellite links.

Original Press Release:

High Linearity Direct Conversion Quadrature Demodulators Simplify Design and Reduce Costs for High Performance RF Receivers

MILPITAS, CA - September 15, 2003 - Two new direct conversion quadrature demodulators from Linear Technology Corporation simplify radio design for cellular basestations and microwave and satellite links. Linear Technology's LT5515 and LT5516 Direct Conversion Quadrature Demodulators deliver exceptionally high linearity, providing more flexible system design and wide spur-free dynamic range. These devices significantly reduce costs compared to discrete solutions by integrating on a single chip the functionality of a signal splitter, two high linearity down-converting mixers, a precision local oscillator quadrature generator (0°/90°), and 260 MHz bandwidth output buffers with single-pole, low pass filters on each of the outputs.

The LT5515 and LT5516 have applications in cellular infrastructure and in microwave and satellite links, where they directly convert an RF signal to baseband In-phase (I) and Quadrature-phase (Q) components. The devices' matched I and Q channels ensure precise gain and phase matching, so that significantly less calibration is required. These direct conversion receiver ICs eliminate the need for additional Intermediate Frequency (IF) stages, local oscillators, and associated filtering.

The LT5515 operates over an input frequency range of 1.5GHz to 2.5GHz, and the LT5516 operates with RF input from 0.8GHz to 1.5GHz. Both devices are designed for high linearity applications. These include wireless infrastructure of all types, such as basestations for GSM, CDMA, W-CDMA and fixed wireless communications, as well as for satellite and microwave receivers, high-performance radios, and instrumentation.

The LT5515 and LT5516 are offered in 4mm x 4mm QFN packages. Pricing starts at $ 6.75 each for the LT5515 and $ 7.40 each for the LT5516 in 1,000 piece quantities.

Summary of Features: LT5515/LT5516
1.5GHz - 2.5GHz (LT5515)
800MHz - 1.5GHz (LT5516)
High Input IIP3: >20dBm
High Input IIP2: >50 dBm
DC-Coupled Baseband Outputs
I/Q Output Gain Mismatch: <0.3dB
I/Q Output Phase Mismatch: typical 1°
LO Drive Level: - 5dBm
4.5V to 5.25V Supply Voltage Range with Shutdown Mode (2µA Typical Supply)
4mm x 4mm QFN Package

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 frequency devices. 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.

Note: LT, AND LTC are registered trademarks of Linear Technology Corp.

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