Analog Devices' class H VDSL line driver amplifier incorporates patented signal power tracking technology

NORWOOD, USA: Analog Devices Inc. (ADI), a world leader in semiconductors for mixed-signal processing applications and leading supplier of signal conditioning technology, introduced a dual-port DSL line driver Class H amplifier that reduces power consumption and system cost for designers of high-speed ADSL2+/VDSL2 line cards.

The ADLD8404 is the industry’s first Class H VDSL line driver and reduces power use by more than 20 percent compared to competing Class AB amplifiers. The new driver’s size-efficient package (4x4mm) also allows telecommunications operators to increase the port density of their DSLAM (digital subscriber line access multiplexer) line cards, resulting in further operating cost savings.

The dual-port ADLD8404 consists of two differential, high-output current, low-power operational amplifiers. The driver incorporates Analog Devices’ patented Adaptive Linear Power technology (U.S. Patent No. 6636103), a technique that tracks ADSL2+/VDSL2 input signals on two channels simultaneously, and then dynamically selects the higher peak.

By ensuring the tracking supply is always at the highest level, the new line driver eliminates clipped signals and distortion even when operating at the VDSL2 transmission frequencies of up to 17.6 MHz.

The dual-port ADLD8404 Class H line driver integrates two charge pumps on-chip, allowing line card designers to cost-effectively support higher channel densities in multi-port DSLAM access concentrators that distribute broadband signals to hotels and large, multi-tenant commercial and residential buildings.