AD8047ARZ vs OPA657U vs AD8047ARZ-REEL7 Comparison

The AD8047ARZ is a general purpose voltage feedback Operational Amplifier for use with pin diode receivers. The AD8047 is unity gain stable. The AD8047, which utilize a voltage feedback architecture, meet the requirements of many applications that previously depended on current feedback amplifiers. A proprietary circuit has produced an amplifier that combines many of the best characteristics of both current feedback and voltage feedback amplifiers. For the power (6.6mA maximum), the AD8047 exhibits fast and accurate pulse response (30ns to 0.01%) as well as extremely wide small signal and large signal bandwidth and low distortion. The AD8047 is low distortion and cap load drive make the AD8047 ideal for buffering high speed ADCs. It is suitable for 12-bit/10 MSPS or 8-bit/60 MSPS ADCs.

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Low distortion and low noise

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High speed

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Drives 50pF capacitive load

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Settling 30ns to 0.01%, 2V step

The OPA657U is a high-gain bandwidth low-distortion voltage-feedback Operational Amplifier with a low-voltage noise JFET-input stage to offer a very high dynamic range amplifier for high-precision ADC (analog-to-digital converter) driving or wideband transimpedance applications. Photodiode applications see improved noise and bandwidth using this decompensated, high-gain bandwidth amplifier. Very low level signals can be significantly amplified in a single OPA657 gain stage with exceptional bandwidth and accuracy. Having a high 1.6GHz gain bandwidth product gives greater than 10MHz signal bandwidths up to gains of 160V/V (44dB). The very low input bias current and capacitance supports this performance even for relatively high source impedances. Broadband photodetector applications benefit from the low-voltage noise JFET inputs for the OPA657. The JFET input contributes virtually no current noise while for broadband applications, a low voltage noise is also required.

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Available in high grade with improved DC specifications

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Fast overdrive recovery

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1.6GHz High gain bandwidth

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±250µV Low-input offset voltage

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2pA Low-input bias current

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4.8nV/√Hz Low-input voltage noise

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70mA High-output current

Product Details The AD8047 and AD8048 are very high speed and wide bandwidth amplifiers. The AD8047 is unity gain stable. The AD8048 is stable at gains of two or greater. The AD8047 and AD8048, which utilize a voltage feedback architecture, meet the requirements of many applications that previously depended on current feedback amplifiers. A proprietary circuit has produced an amplifier that combines many of the best characteristics of both current feedback and voltage feedback amplifiers. For the power (6.6 mA max) the AD8047 and AD8048 exhibit fast and accurate pulse response (30 ns to 0.01%) as well as extremely wide small signal and large signal bandwidth and low distortion. The AD8047 achieves -54 dBc distortion at 20 MHz and 250 MHz small signal and 130 MHz large signal bandwidths. The AD8047 and AD8048"s low distortion and cap load drive make the AD8047/AD8048 ideal for buffering high speed ADCs. They are suitable for 12 bit/10 MSPS or 8 bit/60 MSPS ADCs. Additionally, the balanced high impedance inputs of the voltage feedback architecture allow maximum flexibility when designing active filters. The AD8047 and AD8048 are offered in industrial (-40°C to +85°C) temperature ranges and are available in 8-lead PDIP and SOIC packages. An evaluation board is available for this product and may be ordered using the following product number: AD8047-EB and AD8048-EB. Schematic and layout for this evaluation board is contained in the product data sheet. AD8047 (Gain 1 Stable) PDIP and SOIC AD8048 (Gain 2 Stable) PDIP and SOIC ### Features and Benefits

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Wide Bandwidth, G = +1

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5.8 mA Typical Supply Current

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Low Distortion, (SFDR) Low Noise

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5.2 nV/vHz Noise

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Drives 50 pF Capacitive Load

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High Speed