Analog Devices Announces Industry’s First Fully Differential Attenuating Precision Amplifier

The AD8475 amplifier solves a common problem in industrial, instrumentation and medical applications where signals up to ±10 V are interfaced to single-supply ADCs. The AD8475 is capable of driving ADCs (analog-to-digital converters) with up to 18 bits of resolution and 4-MSPS (million sample per second) throughput with high accuracy and low power consumption. This amplifier features selectable attenuating gains of 0.4x and 0.8x and level shifting for differential inputs up to ±12 V. The AD8475 is effective for driving low-voltage, high-precision differential input SAR ADCs in high-voltage applications, while saving board space and lowering power consumption.



In applications where signals up to ±10 V and ±5 V are interfaced to single-supply 5-V or 3-V ADCs, the AD8475 simplifies the design by integrating the two signal levels, eliminating the need for designers to use multiple components to achieve similar results. Strong performance specifications, such as 10-nV/√Hz output noise, 100-MHz bandwidth, and a 50-V/µsec slew rate, allow the AD8475 to drive precision ADCs, including ADI’s AD7986 18-bit 2-MSPS ADC , AD7641 18-bit 2-MSPS SAR ADC, and AD7622 16-bit 2-MSPS differential ADC. With low distortion of 110-dB THD+N, the AD8475 is also suitable for driving high- speed sigma-delta ADCs.



AD8475 Fully Differential Attenuating Precision Amplifier Key Features:



* Two standard attenuating pin-strappable gain options: 0.4x and 0.8x.

* Differential rail-to-rail output drives switched capacitor SAR or sigma-delta ADCs.

* Over-voltage protection from industrial input voltages up to ±15 V, even while operating on a single supply.

* The VOCM pin adjusts the output voltage common mode for level shifting.

* Drive capability and flexible gain options are effective for DAC output line driving.

* Power supply: 3 V to 10 V or (dual) ±1.5 V to ±5 V.