Analog Devices’ new chip process benefits high-voltage amplifiers

ADI’s i Polar process allows many industrial equipment designs to migrate from older SOIC-packaged ICs to much smaller TSOT-23 packages (lower left). Smaller size allows for simpler board layout or leaves real estate for other functions.

Using a manufacturing process that Analog Devices Inc. (ADI) calls the “most significant re-engineering of 36-V bipolar technology in nearly 20 years,” ADI has recently introduced a suite of amplifiers designed to meet demanding signal conditioning requirements of high-voltage industrial/instrumentation equipment. With operating voltages up to i Polar”—replaces bulky diffusion layers of traditional bipolar processes that have reached their limits, increasing transistor density and performance.

New i Polar process uses a lateral dielectric isolated trench technique, along with re-engineered transistors optimized for speed, noise, matching, linearity, and stability. Bandwidth of NPN- and PNP-type transistors is reportedly at least 750 MHz. i Polar process is a complement to i CMOS semiconductor manufacturing process technology, also introduced by ADI in late-2004, which resulted in 15 new products (see January 2005 Information Control Monthly E-Newsletter ).

i Polar process provides precision linear ICs that enhance analog signal processing, while submicron 30-V i CMOS process is used to manufacture highly integrated mixed-signal devices, says the company. Development of these processes came from recognition of a growing gap between industrial equipment’s continuing need for high-voltage signals (

Eric Nolan, product marketing manager for precision amplifiers at Analog Devices, told Control Engineering that even at 36 V (channels per system, smaller package sizes, reduced electric noise, higher controller precision, and lower power consumption, adds Nolan.

3 initial device families

Initially, three smaller, higher performance, and lower power amplifier models are being introduced:

AD8675 —dubbed the industry’s lowest-noise, 36-V precision amplifier—has voltage noise density under 3 nV/rtHz and rail-to-rail output, while reportedly offering 30% power reduction, 75% lower input bias current, and 65% less temperature drift. The device also has three times the bandwidth and half the cost and size of competing amplifiers. Typical applications are automated test equipment, analytical instruments, and industrial controls.

AD8677 operational amplifier packs improved performance into a tiny package, reducing board space by 75%. The OP07-type device features 75-creasing PSRR (power supply rejection ratio) and CMRR (common mode rejection ratio). High PSRR and CMRR greatly improve immunity to often-noisy industrial environments.

ADA4004-4 , a quad bipolar precision amplifier, claims extremely low noise capability. Reportedly, it achieves voltage noise density of 2 nV/rtHz at just 1.7 mA/amp of supply current. ADA4004-4 also reduces package area up to 70% compared to competitive amplifiers. Reduced power and size allow the device to operate without cooling fans or heat sinks required by competing devices.

All three devices are sampling, with production expected in September 2005 for AD8675 and AD8677 (October 2005 for ADA4004-4). Pricing per unit is $1.17 for AD8675; $0.75 for AD8677; and $3.04 for ADA4004-4—all in 1,000-piece quantities.

—Frank J. Bartos, executive editor, Control Engineering, fbartos@reedbusiness.com

Do you have experience and expertise with the topics mentioned in this content? You should consider contributing to our CFE Media editorial team and getting the recognition you and your company deserve. Click here to start this process.