ADSD-1420S-EX DELTA [Delta Electronics, Inc.], ADSD-1420S-EX Datasheet - Page 3

• Manufacturer Part Number: ADSD-1420S-EX
• Description: Dual 14-Bit, 20MSPS Sampling A/D Converter
• Manufacturer: DELTA [Delta Electronics, Inc.]

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TECHNICAL NOTES
1. Rated performance requires using good high-frequency cir-
CALIBRATION PROCEDURE
1. Connect the converter per Figure 3. Apply a pulse of 50
2. Zero (Offset) Adjustments
3. Repeat above step for Analog Input B (Pin 40). Use trimpot
Apply a precision voltage reference source between
cuit board layout techniques. Connect the digital and
analog grounds to one point, the analog ground plane
beneath the converter. Due to the inductance and resis-
tance of the power supply return paths, return the analog
and digital ground separately to the power supplies.
nanoseconds typical to START CONVERT (pin 11) at a rate
of 2MHz. This rate is chosen to reduce flicker if LED's are
used on the outputs for calibration purposes.
ANALOG INPUT A (pin 1) and SIGNAL GROUND (pin 3),
then adjust the reference source output per Table 2. Adjust
trimpot R1 until the code flickers equally between 10 0000
0000 0000 and 10 0000 0000 0001.
R2 for the zero (Offset) adjustment .
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Figure 2. ADSD-1420S Timing Diagram
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4. To confirm proper operation of the device, vary the precision
MSB
11 1111 1111 1111
11 1000 0000 0000
11 0000 0000 0000
10 0000 0000 0000
01 0000 0000 0000
00 1000 0000 0000
00 0000 0000 0001
00 0000 0000 0000
reference voltage source to obtain the output coding listed
in Table 3.
OUTPUT CODING
Range
±2.5V
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Input
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Table 2. Offset Adjustment
LSB
Table 3. Output Coding
INPUT RANGE
+2.499695
+1.875000
+1.250000
±0.000000
–1.250000
–1.875000
–2.499695
–2.500000
±2.5V
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ADSD-1420S
Offset Adjust
+0.000153V
+1/2 LSB
+FS – 1LSB
+3/4FS
+1/2FS
0
–1/2FS
–3/4FS
–FS+1LSB
–FS
BIPOLAR
SCALE
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