acquisitionZONE Products for the week of July 26, 2004
Analog Devices, Inc., a global leader in high-performance semiconductors for signal-processing applications and the world leader in amplifiers, announced a new family of precision operational amplifiers that deliver the optimal combination of low noise and low power at the higher speeds required by communications applications, and the higher output drive capability necessary for audio applications. The AD8615/16/18 family of single, dual, and quad operational amplifiers with rail-to-rail inputs and outputs are the latest products to use Analog Devices' patented DigiTrim digital trimming technique, eliminating the need for costly accuracy adjustments. Featuring 24 MHz bandwidth and 0.002% total harmonic distortion (THD), the new amplifier family is twice as fast and has 60% lower THD than the previous generation, easily meeting the performance requirements of optical networking and data acquisition applications. Audio applications benefit from the family's higher output drive, which increases current capacity by up to 50% to drive heavy loads in portable equipment such as cell phone headsets.
"This new generation of operational amplifiers enables us to extend our product portfolio to meet the growing demand for higher accuracy amplifiers in communications and audio applications that benefit from higher speed and output drive capability," said Steve Sockolov, product line director for precision amplifiers at Analog Devices. "By offering a complete range of precision amplifiers that are optimized to deliver maximum performance and value, we are meeting the design specifications of a wide variety of high-volume, cost-sensitive applications, from bar code scanners to GSM phones."
Fully-specified to operate from single 2.7-V to 5-V supplies, the parts feature reduced offset voltage and offset related errors, low input voltage noise, and low input current noise. The combination of 24 MHz bandwidth, 65 µV max offset voltage, 8 nV/vHz noise, and 1 pA max input bias current make these amplifiers suitable for a wide variety of applications, including filters, integrators, photodiode amplifiers, high impedance sensors used in optical communications, GPS receivers, data acquisition, industrial controls and medical instrumentation.
The AD8616 and AD8618 offer 150-mA output drive capability, making them
ideal for audio line drivers and other applications driving heavy loads
in portable and low powered instrumentation, audio amplification for portable
devices, portable phone headsets, bar code scanners, and multipole filters.
The ability to swing rail to rail at both the input and output increases
the available dynamic range. This, combined with low offset errors, enables
designers to buffer CMOS analog-to-digital converters (ADCs), digital-to-analog
converters (DACs), ASICs, and other wide output swing devices in single-supply
systems. The rail-to-rail output and low distortion work particularly well
with the AD5541 16-bit serial input, voltage-output DAC to maintain the
accuracy needed in data acquisition systems and automated test equipment.
analogZONE Says . . .
The press release for this new family tends to over-emphasize the bandwidth capabilities. The gain-bandwidth product is quoted in the preliminary data sheet as 20 MHz so for any useful amplifier operation, with a gain of 2 or higher, we actually have 10 MHz or less to play with. No full-power bandwidth is quoted and neither is there a 0.1-dB flatness, nor is there any indication of the phase response of the devices at different gain levels. There is also no number quoted for inter-channel isolation in the dual and quad devices (the AD8616 and AD8618).
Those things said these devices look like they will be ideal as audio line drivers and filters. The outputs go to within 50 mV of the rail at output high and 20 mV at output low with a 3-V supply, and 25 mV and 15 mV with a 5-V rail. With a very reasonable noise performance of 6 nV/rtHz, at 10 kHz, and the rail-to-rail performance will also allow the devices to be used in data acquisition circuits up to maybe 12 bits.
The output current that can be sourced or sunk is quoted at 150 mA at 3 V and 50 mA (a typo one presumes) at 5 V. The quiescent at 3 V is a typical 1.6 mA per amplifier at 3 V and 1.3 mA at 5 V.
Although the dual and quad are fully released the preliminary data sheet is hardly testament to that fact.
These will be very competitive in the marketplace and have been priced as such. In addition to the audio, data acquisition and filter roles they may also find their way into consumer SDTV applications.
The AD8615 is sampling with production scheduled for September 2004. It is in a SOT-23-5. The AD8616 and AD8618 are in production with the former in both a SO-8 and MSOP-8, and the latter in SO-14 and TSSOP-14. The AD8615 is priced at $0.75, the AD8616 at $1.15, and the AD8618 at $2.05, all in 1000-piece lots.