AD823

Dual, 16 MHz, Rail-to-Rail FET Input Amplifier

Courtesy/Thanks to: Analog Devices

Description: The AD823 is a dual precision, 16 MHz, JFET input op amp that can operate from a single supply of 3.0 V to 36 V or from dual supplies of ±1.5 V to ±18 V. It has true single-supply capability with an input voltage range extending below ground in single-supply mode. Output voltage swing extends to within 50 mV of each rail for IOUT ≤ 100 μA, providing outstanding output dynamic range.

An offset voltage of 800 μV maximum, an offset voltage drift of 2 μV/°C, input bias currents below 25 pA, and low input voltage noise provide dc precision with source impedances up to a Gigaohm. It provides 16 MHz, −3 dB bandwidth, −108 dB THD @ 20 kHz, and a 22 V/μs slew rate with a low supply current of 2.6 mA per amplifier. The AD823 drives up to 500 pF of direct capacitive load as a follower and provides an output current of 15 mA, 0.5 V from the supply rails. This allows the amplifier to handle a wide range of load conditions.

This combination of ac and dc performance, plus the outstanding load drive capability, results in an exceptionally versatile amplifier for applications such as A/D drivers, high speed active filters, and other low voltage, high dynamic range systems. The AD823 is available over the industrial temperature range of −40°C to +85°C and is offered in both 8-lead PDIP and 8-lead SOIC packages.

FEATURES
Single-supply operation
Output swings rail-to-rail
Input voltage range extends below ground
Single-supply capability from 3 V to 36 V
High load drive
Capacitive load drive of 500 pF, G = +1
Output current of 15 mA, 0.5 V from supplies
Excellent ac performance on 2.6 mA/amplifier
−3 dB bandwidth of 16 MHz, G = +1
350 ns settling time to 0.01% (2 V step)
Slew rate of 22 V/μs
Good dc performance
800 μV maximum input offset voltage
2 μV/°C offset voltage drift
25 pA maximum input bias current
Low distortion: −108 dBc worst harmonic @ 20 kHz
Low noise: 16 nV/√Hz @ 10 kHz
No phase inversion with inputs to the supply rails
APPLICATIONS
Battery-powered precision instrumentation
Photodiode preamps
Active filters
12-bit to 16-bit data acquisition systems
Medical instrumentation