The AD844 is a high speed monolithic operational amplifier
fabricated using Analog Devices’ junction isolated complementary
bipolar (CB) process. It combines high bandwidth and very
fast large signal response with excellent dc performance. Although
optimized for use in current-to-voltage applications and as an
inverting mode amplifier, it is also suitable for use in many
noninverting applications.
The AD844 can be used in place of traditional op amps, but its
current feedback architecture results in much better ac performance,
high linearity, and an exceptionally clean pulse response.
This type of op amp provides a closed-loop bandwidth that is
determined primarily by the feedback resistor and is almost independent
of the closed-loop gain. The AD844 is free from the slew
rate limitations inherent in traditional op amps and other
current-feedback op amps. Peak output rate of change can be over
2000 V/μs for a full 20 V output step. Settling time is typically
100 ns to 0.1%, and essentially independent of gain. The AD844
can drive 50 Ω loads to ±2.5 V with low distortion and is short
circuit protected to 80 mA.
The AD844 is available in four performance grades and three
package options. In the 16-lead SOIC (R) package, the AD844J is
specified for the commercial temperature range of 0°C to 70°C.
The AD844A and AD844B are specified for the industrial
temperature range of –40°C to +85°C and are available in the
16-Lead SOIC
(R) Package
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8-Lead PDIP (N) and
CERDIP (Q) Packages
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AD844
CERDIP (Q) package. The AD844A is also available in an
8-lead PDIP (N). The AD844S is specified over the military temperature
range of –55°C to +125°C. It is available in the
8-lead CERDIP (Q) package. A and S grade chips and devices
processed to MIL-STD-883B, REV. C are also available.
PRODUCT HIGHLIGHTS
1. The AD844 is a versatile, low cost component providing an
excellent combination of ac and dc performance.
2. It is essentially free from slew rate limitations. Rise and fall
times are essentially independent of output level.
3. The AD844 can be operated from ± 4.5 V to ±18 V power
supplies and is capable of driving loads down to 50 Ω, as well
as driving very large capacitive loads using an external network.
4. The offset voltage and input bias currents of the AD844 are
laser trimmed to minimize dc errors; VOS drift is typically
1 μV/°C and bias current drift is typically 9 nA/°C.
5. The AD844 exhibits excellent differential gain and differential
phase characteristics, making it suitable for a variety of
video applications with bandwidths up to 60 MHz.
6. The AD844 combines low distortion, low noise, and low
drift with wide bandwidth, making it outstanding as an
input amplifier for flash A/D converters.