GENERAL DESCRIPTION

The AD8311 is a complete low cost subsystem for the precise control of RF power amplifiers operating in the frequency range 0.1 GHz to 2.5 GHz and over a typical dynamic range of 50 dB. It is intended for use in cellular handsets and other batteryoperated wireless devices. The log amp technique provides a much wider measurement range and better accuracy than controllers using diode detectors. In particular, its temperature stability is excellent over a specified range of −40°C to +85°C.

FEATURES

Complete RF detector/controller function

>50 dB range at 0.9 GHz (−48 dBm to +3 dBm re 50 Ω)

Accurate scaling from 0.1 GHz to 2.5 GHz

Temperature-stable linear-in-dB response

Log slope of 23 mV/dB, intercept at −60 dBm at 0.9 GHz

True integration function in control loop

Low power: 20 mW at 2.7 V

APPLICATIONS

Single, dual, and triple band mobile handset (GSM, DCS, EDGE)

Transmitter power control