NTE2054 NTE Electronics, Inc., NTE2054 Datasheet - Page 3

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

Circuit Description (Cont’d):
The timing for the NTE2054 is supplied by a 786Hz ring oscillator, and the input at Pin6 determines
the sampling rate. A 5V input provides a high–speed sampling rate (96Hz), and grounding or floating
Pin6 provides a low–speed (4Hz) sampling rate. When Pin6 is fixed at +1.2V (by placing a 12k resistor
between Pin6 and the +5V supply) a “hold” feature is available. While the NTE2054 is in the hold
mode, sampling continues at 4Hz but the display data are latched to the last reading prior to the ap-
plication of the 1.2V. Removal of the 1.2V restores continuous display changes. Note, however, that
the sampling rate remains at 4Hz.
The “EEE” or “–––” displays indicate that the range of the system has been exceeded in the positive
or negative direction, respectively. Negative voltages to –99mV are displayed with the minus sign in
the MSD. The BCD code is 1010 for a negative overrange (–––) and 1011 for a positive overrange
(EEE).
Digit Select Output MSD
Digit Select Output NSD
Digit Select Output LSD
16
1
BCD Output 2
BCD Output 2
.870 (22.0) Max
.100 (2.54)
Hold/Bypass
.700 (17.78)
Zero Adjust
GND
Pin Connection Diagram
1
0
1
2
3
4
5
6
7
8
9
8
.200 (5.08)
16
15
14
13
12
11
10
9
.099 (2.5) Min
Max
BCD Output 2
BCD Output 2
V (+)
Gain Adjust
Integrating Cap
High Input
Low Input
Zero Adjust
.260 (6.6)
3
2
Max