ADC-208A Datel, Inc., ADC-208A Datasheet - Page 3

• Manufacturer Part Number: ADC-208A
• Description: Sampling A/D Converters
• Manufacturer: Datel, Inc.

5. The process that is used to fabricate the ADC-208A
6. For clock rates less than 100kHz, there may be
7. Connect the converter appropriately; a typical
8. Zero Adjustment - Adjusting the voltage at
9. Full Scale Adjustment - Adjusting the voltage at
DATEL, Inc., Mansfi eld, MA 02048 (USA)
eliminates the latchup phenomena that has plagued
CMOS devices in the past. These converters do not
require external protection diodes.
some degradation in offset and differential nonlinearity.
Performance may be improved by increasing the clock
duty cycle (decreasing the time spent in the sample
mode).
connection circuit is shown in Figure 2. Then apply an
appropriate clock input.The reference input should be
held to ±0.1% accuracy or better. Do not use the +5V
power supply as a reference without precision regulation
and high-frequency decoupling capacitors.
–REFERENCE (pin 3) adjusts the offset or zero of the
device. Pin 3 can be tied to GROUND for operation
without adjustments
+REFERENCE (pin 9) adjusts the gain of the device. Pin
9 can be tied directly to a +5V reference for operation
without adjustment.
®
0.1µF
0.1µF
4.7µF
4.7µF
+
5
HA-5033
+
12
+15
10
–15
11
10
®
+5V
HP2811
+15V
Tel: [phone] Fax: [phone]
REF. D2
2
4
Figure 2. ADC-208A Typical Connection Diagram
6
5
10k
1.5k
1.5k
1k
1k
1k
2k
2k
2
3
LM324
1-N
1+N
+15V
0.1µF
0.1µF
0.1µF
3
20MHz CLOCK
1
10.Integral Nonlinearity Adjustments - Provision is made
4.7µF
+0.02V
+1.28V
+2.54V
+2.56V
+2.58V
+3.84V
+5.10V
ANALOG
INPUT
for optional adjustment of Integral Nonlinearity through
access of the reference's ¼, ½, and ¾ full scale points.
For example, the REF. MIDPOINT (pin 6) can be tied to
a precision voltage halfway between +REFERENCE and
–REFERENCE. Pins 6, 18 and 20 should be bypassed
to GROUND through 0.1µF capacitors for operation
without INL adjustments
0.00V
Note:
Values shown here are for a +5.12Vdc reference. Scale other refereces
proportionally. (+REF=+5.12V, –REF=GND, ¼, ½, and ¾ References
FS=No Connection)
+
CLOCK 2
VIN 5,7
0.1µF
+½ FS+ILSB
+½ FS-ILSB
Table 1. ADC-208A Output Code
Zero 0000
0.01µF
4.7µF
+1 LSB
+¼ FS
+½ FS
+¾ FS
CODE
E–mail: [e-mail]
+
+FS
+5V
R¾
R¼
B8
B7
B6
B5
B4
B3
B2
B1
6
5
10
LM324
9
1-N
1+N
24 (LSB)
23
22
21
17
16
15
14 (MSB)
20
18
LM324
12
13
1-N
1+N
DATA
1234
LM324
0000
0000
0100
0111
1000
1000
1100
1111
1-N
1+N
7
8
14
4.7µF
DATA
5678
0000
0001
0000
1111
0000
0001
0000
1111
4.7µF
+
4.7µF
+
Internet: www.datel.com
ADC-208A
0.1µF
+
0.1µF
DECIMAL HEX
0.1µF
127
128
129
192
255
64
0
1
C0
FF
00
01
40
7F
80
81