36V precision JFET-input operational amplifier from ADI

30th August 2009

Analog Devices

ES Admin

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Analog Devices has introduced a compact, 36-volt precision JFET-input (junction field-effect transistor input) operational amplifier (op amp) with the industry’s lowest noise and distortion over the widest temperature range. The 19-MHz ADA4627 JFET-input op amp specifies 5 pA (picoamp) maximum bias current at 25 degrees C and 500 pA maximum over the industrial temperature range of –40 degrees C to 85 degrees C, which is ten times lower than competing JFET-input amplifiers. The ADA4627 JFET-input op amp also offers best-in-class dc precision with very low offset drift of 2µV//C maximum over the -40 degrees C to +125 degrees C extended industrial temperature range, which is three times better than competitive offerings.

Designed for applications that require accurate signal acquisition and fast settling times, such as optical, broadband and microwave communications systems; high-speed data acquisition systems; professional audio equipment; medical and electronic instrumentation; and automated test equipment—the ADA4627 JFET-input op amp is the first product created with ADI’s dielectrically-isolated iPolar® 36-V precision process technology. This proprietary process is optimised for linear circuits and enables both higher performance and extended signal chain integration in industrial and instrumentation applications.

The ADA4627 JFET-input op amp reduces signal distortion by a factor of two featuring an 82V/µS (micro second) slew rate, 120-dB (typical) open-loop gain, and high output current capacity. The exceptional combination of high drive, high slew rate and high open-loop gain also allows the ADA4627 to achieve the low-distortion levels required by precision instrumentation and professional audio equipment while driving impedances as low as 600 ohms.

The ADA4627 has 6.1-nV/rt-Hz voltage noise and 120-µV (microvolt) typical offset voltage (200 µV/300µV max for the A/B grades). The ±18-V ADA4627 JFET-input op amp operates from standard ±12-V and ±15-V industrial power supplies. It has a wide ±5-V to ±18-V operating-voltage range and is well-suited to functions that require accurate reproduction over a wide frequency range with minimal loading, including ADC (analogue-to-digital converter) drivers and buffers, DAC (digital-to-analogue converter) output buffers, high-source-impedance sensors and photo diodes.