AD8021ARZ

The AD8021 is an exceptionally high-performance voltage feedback amplifier optimized for 16-bit resolution systems. It combines the industry’s lowest voltage noise (2.1 nV/sqrtHz) with low current noise (2.1 pA/sqrtHz) at a quiescent supply current of just 7mA on +/-5V rails. The amplifier supports supply voltages from +/-2.25V to +/-12V as well as single 5V operation. A compensation pin allows constant bandwidth from G=-1 to G=-10, and an output disable pin reduces supply current to 1.3mA when the amplifier is not in use.

The AD8021 uses a voltage feedback architecture with a custom compensation node that allows external capacitance to set the frequency response. The input stage employs a low-noise differential pair biased for optimal noise-speed tradeoff. At G=-1, the bandwidth reaches 200MHz with constant bandwidth maintained up to G=-10. The output stage provides low distortion (-93 dBc HD2 at 1MHz) suitable for driving 16-bit ADCs. The disable function opens the output and reduces quiescent current, enabling multiplexed signal chains.

• 16-bit SAR ADC driver with low distortion
• High-speed signal processing front-ends
• Medical imaging and ultrasound systems
• Precision test and measurement equipment
• Active filters requiring low noise and wide bandwidth