New 16-V operational amplifiers for industrial, instrumentation and consumer applications from Analog Devices

Analog Devices’ newest precision operational amplifiers , the AD8663 and the AD8638 deliver a combination of industry- best accuracy, power efficiency and versatility with a wide 5-V to 16-V operating range for an assortment of industrial, medical and consumer applications. Manufactured on Analog Devices’ proprietary iCMOS™ high-voltage industrial process technology, the new precision op amps are available in small packages making them ideal for highdensity and portable applications where board space is at a premium.

The AD8663 is a 16-V precision, low noise, rail-to-rail operational amplifier. Incorporated with Analog Devices’ patented DigiTrim® in-circuit trimming technology the AD8663 achieves low offset voltage, 90-dB CMRR and 105-dB PSRR. The new device also features superior performance over varying power supplies and temperatures, with a maximum voltage offset drift of 450 μV at +125 ºC over a wide input range. In addition, the AD8663 consumes only 180 μA while keeping low-frequency voltage noise at 21 nV/√Hz.

The combination of high precision, low power consumption, small size and stability over temperature is particularly suited for pressure, temperature and fiber-optic sensors, portable industrial tools and other applications where accuracy must be maintained over fluctuating environmental conditions. Typical applications for the AD8663 are portable and battery-operated applications, such as patient monitors, defibrillators, remote industrial controls and optical sensors.

The AD8638 is a 16-V zerodrift precision op amp designed for industrial instrumentation, automotive and sensor applications that must accommodate wide variations in temperature, power supply, load and input signal without introducing signal conditioning errors. The new op amp extends the operating voltage and temperature range for both singleand dual-supply applications and is the first to combine the size, power and performance advantages of the iCMOS™ industrial manu-facturing process with Analog Devices’ patented auto-zero and lowdrift technologies. The result is a device with 140-dB CMRR and 140 dB PSRR, making it up to 10-dB more accurate than competitive zero-drift op amps.

For designers requiring the highest precision temperature-, current- or pressure measurement in systems using thermocouples, strain gauges and position sensors, the AD8638 features a 10-microvolt offset voltage over temperature and a maximum offset drift of 80 nV/ºC, alleviating the need for additional circuitry such as temperature correction loops. Featuring a 4 times faster output saturation recovery time than other op amps in its class, the new zero-drift op amp is ideal for applications such as sensors in harsh or ruggedized environments or temperature-sensitive feedback and control circuits that are designed to take frequent measurements where the outputs are driven into the supply rails.

The AD8638 works well with Analog Devices’ low-frequency ADCs (AD7732), multiplying DACs (AD7534, AD667), audio DACs (AD1855), voltage references (ADR02, AD780, REF192, AD766) and bridge sensors.

Costs and Availability

The AD8663 precision op amp, and a dual-channel version, the AD8667, are available in full production. The AD8663 is available in an 8- lead LFCSP (3 x 3 mm) for $0.64 per unit or an 8-pin SOIC package for $0.60 per unit, both in 1,000-piece quantities. The AD8667 is available in an 8-pin MSOP for $0.80 per unit or an 8-pin SOIC for $0.78 per unit, both in 1,000 piece quantities. The AD8638 zero-drift op amp is available in full production quantities. The AD8638 ships in a SOT-23 package and is priced at $1.20 per unit in 1,000-piece quantities.