Diamond Systems DMM-16R-AT, User Manual, Page: 33 / 39

DMM-16R-AT User Manual V1.31
www.diamondsystems.com
Page 33
10.5 D/A Conversion Formulas and Tables
The formulas below explain how to convert between D/A codes and output voltages.
Conversion Formulas for Unipolar Output Ranges
Output voltage = (D/A code / 4096) * Reference voltage
D/A code = (Output voltage / Reference voltage) * 4096
Example: Reference voltage = 5V
Output range in unipolar mode = 0
– 5V
Full-scale range = 5V
– 0V = 5V
Desired output voltage = 1V; D/A code = 1V / 5V * 4096 = 819.2 => 819
For a unipolar output range, 1 LSB = 1/4096 * Full-scale range, or 1.22mV in this example.
Here is an illustration of the relationship between D/A code and output voltage for a unipolar output range
(V
REF
= Reference voltage):
D/A Code Output voltage symbolic formula Output voltage for 0
– 5V range
0 0V 0.0000V
1 1 LSB (V
REF
/ 4096) 0.0012V
… … …
2047 V
REF
/ 2 - 1 LSB 2.4988V
2048 V
REF
/ 2 2.5000V
2049 V
REF
/ 2 + 1 LSB 2.5012V
… … …
4095 V
REF
- 1 LSB 4.9988V
Conversion Formulas for Bipolar Output Ranges
Output voltage = ((D/A code
– 2048) / 2048) * Output reference
D/A code = (Output voltage / Output reference) * 2048 + 2048
Example: Reference voltage = 5V
Output range in bipolar mode = 5V
Full-scale range = 5V
– (-5V) = 10V
Desired output voltage = 1V; D/A code = 1V / 5V * 2048 + 2048 = 2457.6 => 2458
For a bipolar output range, 1 LSB = 1/4096 * Full-scale range, or 2.44mV in this example.
Here is an illustration of the relationship between D/A code and output voltage for a bipolar output range (V
REF
= Reference voltage):
D/A Code Output voltage symbolic formula Output voltage for 5V range
0 -V
REF
-5.0000V
1 -V
REF
+ 1 LSB -4.9976V
… … …
2047 -1 LSB -0.0024V
2048 0 0.0000V
2049 +1 LSB 0.0024V
… … …
4095 V
REF
- 1 LSB 4.9976V