a 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/s Good DC Performance 800 V Max Input Offset Voltage 2 V/؇C Offset Voltage Drift 25 pA Max 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
Dual, 16 MHz, Rail-to-Rail FET Input Amplifier AD823 CONNECTION DIAGRAM 8-Pin Plastic Mini-DIP and 8-Lead SOIC OUT1
The AD823 is available over the industrial temperature range of –40°C to +85°C and is offered in both 8-pin plastic DIP and SOIC packages.
RL = 100kΩ CL = 50pF VS = +3V
APPLICATIONS Battery Powered Precision Instrumentation Photodiode Preamps Active Filters 12- to 16-Bit Data Acquisition Systems Medical Instrumentation GND
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 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.
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.
Figure 1. Output Swing, VS = +3 V, G = +1 2 1 0 –1
OUTPUT – dB
Offset voltage of 800 µV max, 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 Gigohm. 16 MHz, –3 dB bandwidth, –108 dB THD @ 20 kHz and 22 V/µs slew rate are provided 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.
–2 –3 –4 –5
VS = +5V G = +1
–6 –7 –8 1k
100k 1M FREQUENCY – Hz
Figure 2. Small Signal Bandwidth, G = +1
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