AD846

This preamp for RIAA phone use uses two op amps by Analog Devices. A switch selects compensation for moving magnet or rrtoving coil pickups.

The AD846 is a monolithic, very high speed operational ampli- fier offering high performance. Although technically classed as acurrent-feedback or transimpedance amplifier, it may be used in much the same way as traditional op amps while providing significant performance benefits. Employing Analog Devices'junction isolated complementary bipolar (CB) process, the AD846 achieves true "12-bit" (0.01%) precision on critical ac and dc parameters, a level of performance unmatched by amplifiersfabricated using either the dielectrically isolated (DI) or other bipolar processes. The AD846 offers significant advantages over conventional high speed operational amplifiers. It maintains a nearly con- stant bandwidth and settling time to 0.01% over a wide range of closed-loop gains. This makes the AD846 ideal for amplifying the residue in multiple-pass analog-to-digital converters. Other advantages include: low input errors and high open-loop transresistance (200 MΩ) into a 500 Ω load, ensuring true12-bit dc accuracy for closed-loop gains from 1 to gainsgreater than 100. This combination of ac and dc perfor-mance makes the AD846 an excellent choice for bufferingprecision high speed DACs and flash ADCs.

The AD846 is available in three performance grades. The AD846Aand AD846B are rated over the industrial temperature rangeof 40°C to +85°C. The AD846S is rated over the full mili-tary temperature range of 55°C to +125°C and is available processed to MIL-STD-883B, Rev C. The AD846 is available in two types of 8-lead packages: plasticmini-DIP and hermetic cerdip. The AD846AR-16 is available in the 16-lead SOIC package. "A" and "S" grade chips are also available.