Smaller op amp provides bigger performance

Edited by the Electronicstalk editorial team May 19, 2005

The AD8677 is one-quarter the size of competing offerings while providing improved accuracy compared with ADI's industry-standard OP07.

Analog Devices has introduced an operational amplifier (op amp) that is one-quarter the size of competing offerings while providing improved accuracy compared with high-performance, ultra-low-offset-voltage op amps like ADI's industry-standard OP07.

Addressing the needs of applications such as industrial PLCs (programmable logic controllers), ATE (automated test equipment) platforms, and machine monitoring systems, the AD8677 is manufactured on ADI's new iPolar trench isolation process technology to reduce power consumption by 40% while maintaining a 75uV (maximum) voltage offset and 1.3uV/C (maximum) drift.

This outstanding level of performance is packed into a tiny 3 x 3mm TSOT-23 (thin small outline transistor) package.

The increased accuracy, small package size and lower power consumption make the AD8677 ideal for precision thermal and current sensing and precision filtering applications that require the high performance of an op amp like the OP07, but also need a reduction in system size.

"Analog Devices set the standard for ultra-low-offset voltage amplifiers with the OP07".

"Now, with the introduction of the AD8677 - made possible by ADI's new iPolar trench isolation process - we are able to improve OP07 performance in one-quarter the footprint", said Steve Sockolov, Product Line Director, Precision Amplifier Group, at Analog Devices.

"This new amp answers the call from designers of instrumentation and test and measurement equipment, who have been demanding low-noise components with greater precision that don't eat up valuable board space".

In addition to the smaller die size enabled by ADI's new iPolar process, the AD8677 provides greater accuracy than the OP07.

Performance enhancements include higher CMRR (common-mode rejection ratio) of 130dB, an enhanced PSRR (power supply rejection ratio) of 110dB and a wider output swing of +/-14V.

The higher CMRR and PSRR improve system performance by increasing immunity to power supply fluctuations and other environmental signal interference.

The 1.2mA power consumption of the AD8677 lowers thermal output relative to competing devices and reduces the need for additional cooling with heatsinks or fans.

The new amp's low input bias current of +/-2nA and high open-loop gain further reduce system errors.

High open loop gain insures linearity and gain accuracy over the wide input signal range of +/-13V, even at high closed loop gains.

With very high 80 degree phase margin, the AD8677 is extremely tolerant of both parasitic capacitance caused by PCB layout and external load and filtering capacitances, making it supremely easy to use.

The AD8677 is sampling now and will be available in production quantities in September 2005.

Fully specified to operate over an extended industrial temperature range of -40 to +125C, the device is available in a 5-lead TSOT-23, as well as 8-lead narrow SOIC (small outline integrated circuit) package.

The AD8677 is priced at $0.75 per unit in 1000-unit quantities.