NTE2055
Integrated Circuit
CMOS, 3
1
/
2
Digit A/D Converter
Description:
The NTE2055 is a high performance, low power, 3
1
/
2
digit A/D converter combining both linear CMOS and
digital CMOS circuits on a single monolithic IC. Available in a 24鈥揕ead DIP type package, this device is de-
signed to minimize use of external components. With two external resistors and two external capacitors, the
system forms a dual slope A/D converter with automatic zero correction and automatic polarity.
The NTE2055 is ratiometric and may be used over a full鈥搒cale range from 1.999V to 199.9mV. Systems using
this device may operate over a wide range of power supply voltages for ease of use with batteries, or with stan-
dard 5V supplies. The output drive conforms with standard B鈥揝eries CMOS specifications and can drive a
low鈥損ower Schottky TTL load.
The high impedance MOS inputs allow applications in current and resistance meters as well as voltmeters.
In addition to DVM/DPM applications, the NTE2055 finds use in digital thermometers, digital scales, remote
A/D, A/D control systems, and in MPU systems.
Features:
D
Accuracy:
鹵0.05%
of Reading
鹵1
Count
D
Two Voltage Ranges: 1.999V and 199.9mV
D
Up to 25 Conversions /s
D
Z
in
> 100M鈩?/div>
D
Auto鈥揚(yáng)olarity and Auto鈥揨ero
D
Single Positive Voltage Reference
D
Standard B鈥揝eries CMOS Outputs: Drives One Low Power Schottky Load
D
Uses On鈥揅hip System Clock, or External Clock
D
Wide Supply Range: e.g.,
鹵4.5V
to
鹵8.0V
D
Overrange and Underrange Signals Available
D
Operates in Auto Ranging Circuits
D
Operates with LED and LCD Displays
D
Low External Component Count
D
Chip Complexity: 1326 FETs
Absolute Maximum Ratings:
DC Supply Voltage, V
DD
to V
EE
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 鈥?.5V to +18V
Voltage, Ant Pin, Referenced to V
EE
, V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 鈥?.5V to V
DD
+0.5V
DC Input Current, Per Pin, I
in
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
鹵10mA
Operating Temperature Range, T
A
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 鈥?0擄 to +85擄C
Storage Temperature Range, T
stg
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 鈥?5擄 to +150擄C
Note 1. This device contains circuitry to protect the inputs against damage due to high static voltages or electric
fields; however, it is advised that normal precautions be taken to avoid applications of any voltage higher
than maximum rated voltages to this high impedance circuit. For proper operation it is recommended that
V
in
and V
out
be constrained to the range V
EE
鈮?/div>
(V
in
or V
out
)
鈮?/div>
V
DD
.
Recommended Operating Conditions:
(V
SS
= 0 or V
EE
)
DC Supply Voltage
V
DD
to Analog GND, V
DD
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +5.0 to 8.0V
V
EE
to Analog GND, V
EE
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 鈥?.8 to 鈥?.0V
Clock Frequency, f
Clk
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 to 400kHz
Zero Offset Correction Capacitor, C
o
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.1
鹵20%碌F
1
2
3
4
