NTE2054 NTE Electronics, Inc., NTE2054 Datasheet - Page 2

• Manufacturer Part Number: NTE2054
• Description: NTE2054, Integrated Circuit A/D Converter For 3 Digit Display
• Manufacturer: NTE Electronics, Inc.

Electrical Characteristics: (T
Note 1. Apply zero volts across V
Note 2. Linearity is measured as a difference from a straight line drawn through zero and positive
Note 3. For applications where negative Pin10 is not operated at Pin7 potential, a return path of not
Note 4. The common–mode input voltage above ground cannot exceed +0.2V if the full input signal
Circuit Description:
The heart of the NTE2054 is the V/I converter and reference–current generator. The V/I converter
converts the input voltage applied between Pin10 and Pin11 to a current that charges the integrating
capacitor on Pin12 for a predetermined time interval. At the end of the charging interval, the V/I con-
verter is disconnected from the integrated capacitor, and a band–gap reference constant–current
source of opposite polarity is connected. The number of clock counts that elapse before the charge
is restored to its original value is a direct measure of the signal induced current. The restoration is
sensed by the comparator, which in turn latches the counter. The count is then multiplexed to the BCD
outputs.
Operating Supply Voltage Range
Supply Current
Input Impedance
Input Bias Current
Unadjusted Zero Offset
Unadjusted Gain
Linearity
Conversion Rate
Conversion Control Voltage
Common–Mode Input
BCD Sink Current at
Digit Select Sink Current at
Zero Temperature Coefficient
Gain Temperature Coefficient
Fast Mode
Slow Mode
(Hold Mode) at Pin6
Voltage Range
Pin1, Pin2, Pin15, and Pin16
Pin3, Pin4, and Pin5
900mV to input and adjust gain potentiometer to give 900mV reading.
full scale. Limits do not include 0.5 count bit digitizing error.
more than 100k
range of 999mV is required at Pin11. That is, Pin11 may not operate higher than 1.2V posi-
tive with respect to GND or 0.2V negative with respect to GND. If the maximum input signal
is less than 999mV, the common–mode input voltage may be raised accordingly.
Parameter
resistance must be provided for input bias currents.
otherwise specified)
Symbol
A
V
11
V+
= +25 C, V+ = 5V, Zero pot centered, gain pot = 2.4k
I
I+
Z
ICR
IB
i
to V
10
100k
Pin10 and Pin11
V
Read Decoded Output
V
Read Decoded Output
Note 1, Note 2
Pin6 = Open or GND
Pin6 = 5V
Note 3, Note 4
V
V
V
V
11
11
BCD
Digit Select
I
I
. Adjust zero potentiometer to give 000mV reading. Apply
= 0V, Zero Pot Centered
= 900mV, Gain Pot = 2.4k
–V
–V
10
10
to V+ on Pin3, Pin4, Pin5
0.5V, at Logic Zero State
Test Conditions
= 0V,
= 900mV,
= 4V at Logic Zero State
–0.2
Min
–12
846
4.5
0.8
0.4
1.6
–1
–
–
–
–
–
–
–
0.005
Typ
100
–80
5.0
1.2
1.6
2.5
96
10
–
–
–
–
4
–
Max
+0.2
+12
954
5.5
1.6
17
+1
–
–
–
–
–
–
–
–
unless
Count
%/ C
Unit
M
mA
mV
mV
mA
mA
V/ V
nA
Hz
Hz
V
V
V