News and New Products

Analog Devices rolls out iPolar signal-conditioning amplifiers

By Jeff Berman, News Editor -- EDN, 5/17/2005

Analog Devices has introduced a new amplifier family, targeting industrial and instrumentation applications, that is based on a trench-isolation process technology the company calls iPolar.

iPolar is a 36V bipolar process that replaces the bulky diffusion layers used in traditional processes with deep trenches, allowing greater transistor density and performance, said Steve Sockolov, product line manager for Analog's precision amplifiers group. "We were learning from our customers that they wanted improvements in higher-voltage processes to get signals into different types of equipment," Sockolov said.

The amplifiers support operating voltages up to ±18V while reducing package size by up to 75% and power consumption by up to 50%, according to the company.

The new amplifiers include:

• the AD8675, a 36V precision amplifier with less than 3nV/rtHz, rail-to-rail output, a 30% power reduction, and 75% lower bias input current
• the AD8677, an operational amplifier that offers 75-µV (max) offset voltage and 1.3-µ/°C (max) temperature drift, while reducing bias current by 50%, lowering power consumption by 40%, and offerings increased PSRR (power supply rejection ratio) and CMRR (common mode rejection ratio)
• the AD4004-4, a low-noise quad bipolar precision amplifier that achieves voltage noise of 2nV/rtHz at 1.7 mA/A of supply current and reduces package area up to 70%.

These amplifiers can easily replace existing parts, increase performance, decrease power consumption, and offer up to 3× the bandwidth of existing parts within the same cooling budget, Sockolov said. Higher open-loop gain, CMRR, and PSRR are important because they isolate products from noise in industrial environments, he added.

"The main benefit [of the iPolar process] is the ability to produce high-performance products using a high-voltage process, with results comparable to CMOS," said Susie Inouye, research director and principal analyst with Databeans, in an e-mail. "This is important for engineers in the industrial market, who are faced with many of the same design issues that are shared in the consumer and communications space, but were never really addressed until now."

The devices are sampling now and will go into full production later this year at prices ranging from $0.75 to $3.04 (1000).