Linear Technology Introduces Broadband 6GHz RMS detector

Linear Technology has introduced the LT5581, a broadband 6GHz RMS detector, featuring 40dB dynamic range and a low operating supply current of 1.4mA. The device is suited for a wide range of power monitor and control applications in portable and battery- powered wireless systems, cellular basestations, picocells and femtocells, fiber optic transmitters and instrumentation. The LT5581 outputs a DC voltage that is linearly proportional to the log input power, mV/dB scaling with exceptional linearity of better than ±1dB across 40dB range. The LT5581's RMS measurement capability provides accurate RF power readings to within ±0.2dB regardless of waveforms that have high crest-factor modulated content, multi-carrier or multitone. The LT5581 offers exceptional accuracy of ±1dB over its operating temperature range of -40°C to 85°C.



Operating over a wide supply voltage range of 2.7V to 5.25V, The LT5581's low power consumption makes it for battery-powered communication and multimedia devices. The LT5581’s wide frequency range extends to applications including WiMAX and wireless systems in the 5GHz ISM bands. The LT5581’s single-ended RF input does not require an external RF transformer, thus simplifying the application design while reducing costs. The LT5581 has a fast response time of 1us rise time to a full power swing, suitable for time-division duplexing systems. The LT5581 also incorporates a shutdown feature. When the LT5581's Enable input pin is pulled low, the chip draws a typical shutdown current of 0.2uA, and a maximum of 6uA. The device is offered in a tiny 8-lead, 3mm x 2mm DFN surface mount package. Pricing starts at $2.29 each in 1,000-piece quantities. The LT5581 is available immediately from stock.