Analog Devices Launches RF/IF Variable-Gain Amplifier

San Diego -- MTT Wireless Week -- Analog Devices, Inc. extended its portfolio of radio frequency integrated circuits with a new analog-control variable-gain amplifier (VGA) that offers high linearity over a broad frequency range for wireless infrastructure applications, such as cellular base station radio transceivers. The AD8368 is optimized to maintain a range of base station radio transceivers. In addition, the AD8368 reduces the number of external components required by integrating an accurate root-mean-square (rms) power detector on chip, which enables a complete automatic gain control (AGC) loop within a small 4 mm × 4 mm IC package.

The AD8368 is capable of sustaining high linearity (OIP3 of 34 dBm at 70 MHz) at the highest intermediate frequencies (IFs), 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 380-MHz 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 signal dynamic range and sensitivity.

"The AD8368 further solidifies ADI's portfolio of high-performance, highly integrated RF ICs for almost all wireless infrastructure standards and architectures," said Peter Real, product line director, RF and Networking Components, Analog Devices. "Providing high linearity up to 380 MHz, single-ended operation, and an on-board detector for AGC loops allows the AD8368 to be used across all the common intermediate frequencies, while simplifying design and reducing component cost. As a result, this solution can be used within multiple sockets in both receive and transmit applications."

The AD8368 provides continuous 34-dB linear-in-dB gain control from –12 dB to + 22 dB. With a 3-dB bandwidth of 800 MHz independent of gain setting, a single-ended input and output drive, and high linearity over the full operating range, the AD8368 is suitable for use in GSM, CDMA2000, W-CDMA, and TD SCDMA cellular base stations. Operating from a single supply voltage of 4.5 V to 5.5 V, the AD8368 consumes 54 mA of current.

The AD8368 is sampling now with full production scheduled for April 2006. The device is available in a 24-pin LFCSP (lead frame chip scale package), and is specified over an operating temperature range of –40°C to +85°C.

SOURCE: Analog Devices, Inc.