Cirrus Logic AN374 - Manual (Page 32)

AN374
32 AN374REV2
Step 2) Red Gain setting
The entry procedure that is required to preform a curve fit for the Color Gain polynomial is detailed in Figure 28.
1. Enter the color LED currents (in Amperes) for different dims. Repeat for different ambient temperatures.
Right click to see options to load data from CSV file.
2. Select “Use Mask” to mask the interpolated NTC code regions not present in the NTC data in the surface
to be fit. Set Mask Low Level to a value relative to 1 to use as weights for the interpolated NTC code
regions on the surface.
3. Enter Weight Factor. Values > 1 favor high dim levels in the fit and values < 1 favors low dim levels.
4. Click the Calculate Coefficients button.
5. Adjust Results. Polynomial coefficients can be modified over and above the fit results.
6. Click the UPDATE REGISTERS button to update the Color System tab under REGISTERS with Q3, Q2,
Q1, and Q0. Values are not written to the chip; only the tab is populated.
Step 1:
Enter the color LED
currents for different dims.
Select graph to view to
check quality of fit. Select 3D view
perspective.
Click Expand to display
the graph in a larger
window
Step 2:
Select “Use Mask”.
Step 3:
Enter the Weight Factor.
Step 5:
Adjust Results.
Step 6:
Click the UPDATE
REGISTERS button.
Step 4:
Click the Calculate
Coefficients button.
Figure 28. SYSTEM DESIGN - Color Gain Tab