Global Sources
EE Times-Asia
Stay in touch with EE Times Asia
EE Times-Asia > Amplifiers/Converters

Variable gain amplifier supports multichannel data access

Posted: 20 Feb 2008 ?? ?Print Version ?Bookmark and Share

Keywords:variable gain amplifier? CMTS channels? ADCs?


Analog Devices Inc. has introduced a general-purpose two-channel, digitally controlled variable gain amplifier (VGA) developed with specific features for today's cable modem termination system (CMTS) upstream receiver applications. The two-channel AD8372 VGA enables designers to incorporate more CMTS channels while simultaneously improving modem performance and the quality of upstream cable signals. The VGA's space-saving design reduces component count and board area by allowing designers to fit more channels into a given space or pack the same number of channels into a smaller area.

For wide-dynamic-range applications, the AD8372 offers a broad 41dB gain range, with 1dB steps and 0.2dB resolution. The gain is programmed through a bidirectional 4-pin, 8bit serial port, which consists of clock, latch, data input and data output lines for each channel. The 41dB control range enables designers to keep input signals above the noise floor, while using the full-scale range of a wider variety of ADCs. The 41dB gain range makes the AD8372 an essential component for multiple cable applications, including CMTS.

The AD8372, which accepts differential inputs and provides differential outputs, requires no baluns. It provides better than 77-dBc second and third harmonic distortion and 55dB common-mode rejection. Compared to competitive products, the AD8372 delivers 35 percent more gain control range and improved second harmonic distortion in roughly 20 percent of the board space.

The AD8372 amplifier is now shipping in production quantities and is available in a compact, thermally enhanced 5mm x 5mm 32-lead LFCSP. The device operates over a temperature range of -40C to 85C. The AD8372 is priced at $6.50 per unit in 1,000-piece quantities.

Article Comments - Variable gain amplifier supports mul...
*? You can enter [0] more charecters.
*Verify code:


Visit Asia Webinars to learn about the latest in technology and get practical design tips.

Back to Top