Chip Duo Eases Base Station Design

The dual-channel AD8376 variable gain amplifier (VGA) and AD6655 IF diversity receiver team up to form a two-chip IF receiver that promises to dramatically improve data bandwidths and capacities for next-generation, multi-carrier wireless base stations compatible with emerging 3G cellular transmission standards. Together, they replace 48 discrete components, and each radio channel can handle up to six carriers. Crowned as the first digitally controlled VGA that enables 1-dB gain-step resolution at the highest IFs, the AD8376 specifies a linearity of OIP3 50 dBm at 140 MHz. The device features a bandwidth of 600 MHz, 5-pin digital interface, and a 24-dB gain range. Operating from a 5V supply at a 50-dBm output, quiescent current is 130 mA. The AD6655 integrates a low-latency peak detector, RMS signal-power monitor, and 14-bit a/d converter delivering up to 150 Msamples/s. A 12-bit version, the AD6653, is also available. The AD6653/5 IF diversity receivers are sampling now with full production set for June. Prices are $57.97 and $97.50 each/1,000, respectively. Sampling now and also slated for production in June, price for the AD8376 VGA is $6.49 each/1,000, while a single-channel version, the AD8375, is priced at $4.49. ANALOG DEVICES INC., Norwood, MA. (800) 262-5643.