Hercules III User Manual Rev A.2
www.diamondsystems.com
Page
72
16.2
Resolution
The resolution is the smallest possible change in output voltage. For a 12-bit DAC the resolution is 1/(2
12
), or
1/4096, of the full-scale output range. This smallest change results from an increase or decrease of 1 in the D/A
code, so this change is referred to as 1 least significant bit (1 LSB ). The value of this LSB is calculated as
follows.
1 LSB = Output voltage range / 4096
Example:
For, Output range = 0-10V,
Output voltage range = 10V
– 0V = 10V
Therefore,
1 LSB = 10V / 4096 = 2.44mV
Example:
For, Output range =
10V;
Output voltage range = 10V
– (-10V) = 20V
Therefore,
1 LSB = 20V / 4096 = 4.88mV
16.3
Output Range Selection
The DACs can be configured for 0-10V or
10V.Two parameters are configured:
•
unipolar/bipolar mode
•
power-up/reset clear mode.
In most cases, for unipolar mode configure the board to reset to zero scale, and for bipolar mode configure the
board for reset to mid-scale. In each case, the DACs reset to 0V.