Hi FormerMember,
We are seeing what looks like inaccuracies in the drive current on the ADPD107. The datasheet says the drive current should be:
LEDPeak = (50.3 + 19.8 * ILED_COARSE) * (0.74 + 0.022 * ILED_FINE) * (0.4 + 0.6 * ILED_SCALE)
We are trying to use these settings create a range of LED drive currents, and we are seeing this behavior:
You can see that the measured response (on a constant material), has some point where an increase would be expected but a decrease occurs. These point also appear to align with changes in the 'scale' setting. Note that the scale variable is multiplied by 10 to make it easier to see in the plot.
Is the equation in the datasheet accurate? I am also attaching a table of the data (PD is response, drive_i is expected drive current):
| PD | coarse | drive_i | fine | scale |
| 935.440677966 | 0 | 16.65936 | 4 | 0 |
| 1057.40229885 | 0 | 18.42992 | 8 | 0 |
| 1118.95454545 | 0 | 19.3152 | 10 | 0 |
| 1181.18823529 | 0 | 20.20048 | 12 | 0 |
| 1241.93023256 | 0 | 21.08576 | 14 | 0 |
| 1426.37647059 | 1 | 21.98336 | 2 | 0 |
| 1387.70114943 | 0 | 23.29896 | 19 | 0 |
| 1614.46987952 | 1 | 24.45088 | 6 | 0 |
| 1701.94047619 | 1 | 25.68464 | 8 | 0 |
| 1794.60465116 | 1 | 26.9184 | 10 | 0 |
| 1936.65116279 | 2 | 28.19264 | 2 | 0 |
| 2058.68965517 | 2 | 29.77488 | 4 | 0 |
| 2100.72619048 | 1 | 31.23656 | 17 | 0 |
| 2291.37647059 | 2 | 32.93936 | 8 | 0 |
| 2419.96470588 | 3 | 34.40192 | 2 | 0 |
| 2523.6741573 | 2 | 36.10384 | 12 | 0 |
| 2566.27380952 | 1 | 38.02224 | 28 | 0 |
| 2690.70786517 | 1 | 39.87288 | 31 | 0 |
| 2964.93975904 | 4 | 41.7508 | 3 | 0 |
| 2169.70114943 | 0 | 43.8616 | 6 | 1 |
| 2306.63855422 | 0 | 46.0748 | 8 | 1 |
| 2448.85416667 | 0 | 48.288 | 10 | 1 |
| 3566.15853659 | 3 | 50.81304 | 19 | 0 |
| 3765.92941176 | 5 | 53.38968 | 7 | 0 |
| 3916.85227273 | 6 | 56.00592 | 4 | 0 |
| 4091.47727273 | 4 | 58.8448 | 18 | 0 |
| 4226.15853659 | 8 | 61.7752 | 0 | 0 |
| 3416.71764706 | 0 | 64.887 | 25 | 1 |
| 4597.01190476 | 4 | 67.9616 | 26 | 0 |
| 3769.11494253 | 0 | 71.5266 | 31 | 1 |
| 4301.30681818 | 1 | 75.007 | 15 | 1 |
| 5148.85365854 | 7 | 79.18688 | 14 | 0 |
| 4650.88235294 | 1 | 82.718 | 20 | 1 |
| 5403.25581395 | 10 | 86.60704 | 6 | 0 |
| 5572.18823529 | 8 | 91.16016 | 16 | 0 |
| 5706.42528736 | 9 | 95.7872 | 14 | 0 |
| 5811.93975904 | 11 | 100.59112 | 9 | 0 |
| 5891.54117647 | 14 | 105.586 | 3 | 0 |
| 6028.63636364 | 10 | 110.64248 | 17 | 0 |
| 6132.56321839 | 8 | 116.872 | 30 | 0 |
| 5825.17647059 | 3 | 122.2058 | 17 | 1 |
| 6255.38372093 | 12 | 128.28824 | 17 | 0 |
| 6314.61111111 | 10 | 134.67792 | 28 | 0 |
| 5995.1547619 | 3 | 141.513 | 25 | 1 |
| 6385.36170213 | 12 | 148.5564 | 25 | 0 |
| 6046.01204819 | 3 | 155.9934 | 31 | 1 |
| 6416.24242424 | 12 | 163.75752 | 31 | 0 |
