Fast, Precision
Comparator
a
AD790
CO NNECTIO N D IAGRAMS
FEATURES
8-P in P lastic Mini-D IP (N)
and Cerdip (Q) P ackages
45 ns m ax Propagation Delay
Single +5 V or Dual ؎15 V Supply Operation
CMOS or TTL Com patible Output
250 V m ax Input Offset Voltage
500 V m ax Input Hysteresis Voltage
15 V m ax Differential Input Voltage
Onboard Latch
60 m W Pow er Dissipation
Available in 8-Pin Plastic and Herm etic Cerdip
Packages
+V
S
1
2
8
7
V
LOGIC
AD790
+IN
–IN
OUTPUT
+
–
3
4
6
5
GROUND
LATCH
–V
S
MIL-STD-883B Processing Available
Available in Tape and Reel in Accordance w ith
EIA-481A Standard
8-P in SO IC (R) P ackage
APPLICATIONS
GROUND
LATCH
1
2
3
4
OUTPUT
8
7
Zero-Crossing Detectors
Overvoltage Detectors
Pulse-Width Modulators
Precision Rectifiers
Discrete A/ D Converters
Delta-Sigm a Modulator A/ Ds
AD790
–
V
LOGIC
–V
S
6
5
+V
S
–IN
+IN
P RO D UCT D ESCRIP TIO N
P RO D UCT H IGH LIGH TS
1. T he AD790’s combination of speed, precision, versatility
and low cost makes it suitable as a general purpose compara-
tor in analog signal processing and data acquisition systems.
T he AD790 is a fast (45 ns), precise voltage comparator, with a
number of features that make it exceptionally versatile and easy
to use. T he AD790 may operate from either a single +5 V sup-
ply or a dual ±15 V supply. In the single-supply mode, the
AD790’s inputs may be referred to ground, a feature not found
in other comparators. In the dual-supply mode it has the unique
ability of handling a maximum differential voltage of 15 V across
its input terminals, easing their interfacing to large amplitude
and dynamic signals.
2. Built-in hysteresis and a low-glitch output stage minimize the
chance of unwanted oscillations, making the AD790 easier to
use than standard open-loop comparators.
3. T he hysteresis combined with a wide input voltage range
enables the AD790 to respond to both slow, low level (e.g.,
10 mV) signals and fast, large amplitude (e.g., 10 V) signals.
T his device is fabricated using Analog Devices’ Complementary
Bipolar (CB) process–which gives the AD790’s combination of
fast response time and outstanding input voltage resolution
(1 mV max). T o preserve its speed and accuracy, the AD790
incorporates a “low glitch” output stage that does not exhibit
the large current spikes normally found in T T L or CMOS out-
put stages. Its controlled switching reduces power supply distur-
bances that can feed back to the input and cause undesired
oscillations. The AD790 also has a latching function which makes
it suitable for applications requiring synchronous operation.
4. A wide variety of supply voltages are acceptable for operation
of the AD790, ranging from single +5 V to dual +5 V/–12 V,
±5 V, or +5 V/±15 V supplies.
5. T he AD790’s power dissipation is the lowest of any compara-
tor in its speed range.
6. T he AD790’s output swing is symmetric between VLOGIC
and ground, thus providing a predictable output under a
wide range of input and output conditions.
T he AD790 is available in five performance grades. The AD790J
and the AD790K are rated over the commercial temperature
range of 0°C to +70°C. T he AD790A and AD790B are rated
over the industrial temperature range of –40°C to +85°C. T he
AD790S is rated over the military temperature range of –55°C to
+125°C and is available processed to MIL-ST D-883B, Rev. C.
REV. B
Inform ation furnished by Analog Devices is believed to be accurate and
reliable. However, no responsibility is assum ed by Analog Devices for its
use, nor for any infringem ents of patents or other rights of third parties
which m ay result from its use. No license is granted by im plication or
otherwise under any patent or patent rights of Analog Devices.
One Technology Way, P.O. Box 9106, Norw ood, MA 02062-9106, U.S.A.
Tel: 617/ 329-4700
Fax: 617/ 326-8703