Variable gain amplifier takes aim at wireless infrastructure

Analog Devices Inc. (ADI) announced an analog-control variable-gain amplifier (VGA) that is optimized for linearity in wireless infrastructure applications, such as cellular base station radio transceivers. The AD8368 is designed to maintain the dynamic range of base station radio transceivers, ensuring that both weak and strong incoming call signals are effectively handled and maintained. In addition, the AD8368 integrates a root-mean-square (rms) power detector on chip, which enables an automatic gain control (AGC) loop within a 4-by-4mm IC package.

The AD8368 features an output third-order intercept of 34dBm at 70MHz, allowing it to be used in all wireless standards, including 2G and 3G, as well as emerging broadband wireless standards such as 802.16 (WiMAX). The 380MHz frequency range of the AD8368 allows the device to be used in both receive and transmit paths within any wireless infrastructure standard where the use of one or more AGC loops optimizes the base station dynamic range or allows the designer to add additional gain for optimal signal dynamic range and sensitivity.

The AD8368 provides continuous 34dB linear-in-dB gain control from -12dB to 22dB. The AD8368 is well suited for use in GSM, CDMA2000, W-CDMA and TD-SCDMA cellular base stations. Operating from a single supply voltage of 4.5Vdc to 5.5Vdc, the AD8368 consumes 54mA of current.

The AD8368 is sampling now with full production scheduled for April 2006. The device is priced at $4.55 per unit in 1,000-piece quantities, is available in a 24-pin LFCSP, and is specified over an operating temperature range of -400C to 850C.

- Janine Love
eeProductCenter