RMS detector features accurate RF power readings

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 suitable for power monitor and control applications in portable and battery-powered wireless systems, cellular base stations, picocells and femtocells, plus fibre optic transmitters and instrumentation.

The LT5581 has a DC voltage output that is linearly proportional to the log input power, providing mV/dB scaling with linearity of better than +/-1dB across a 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 multi-tone.

The LT5581 offers an accuracy of +/-1dB over its operating temperature range of -40C to 85C.

Operating over a supply voltage range of 2.7V to 5.25V, the LT5581's low power consumption makes it suitable for battery-powered communication and multimedia devices.

The instrument'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.

The LT5581 has a response time of 1us rise time to a full power swing, suitable for time-division duplexing systems.

It 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 eight-lead, 3mm x 2mm DFN surface-mount package.

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