HFE0605_McCambridgeandWhitakerHigh Frequency DesignPOWER CONTROLFrom June 2005 High Frequency Electronics Copyright 2005 Summit Technical MediaCombination Closed Loop and VCC Power Control for a GSM/GPRS PABy Paul McCambridge, Xindium Technologies, and Brian Whitaker, Maxim Integrated Products ower control is an important performance specification for GSM/GPRS wireless handsets. This article shows how the MAX4002 low-cost, low-power logarithmic amplifier and power detector, and the XIN9133 quad-band GSM/GPRS power amplifier (PA) are combined in a closed loop power control system with the added advantage of PA protection through supply voltage power control. This results in significant advantages over today’s predominant GSM power control solutions on the market.This application note describes the use of two m……