
Analog Devices
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