Datasheet

21
MSL2021 [DATASHEET]
42062A–LED–02/2013
The MSL2021 modifies the color-adjust string duty cycle using a look-up table. Default values are presented in Table 11-
1; each location in the table corresponds to one temperature. The modification value is stored in the table as an 8-bit
color-adjust duty cycle ratio (SDCR). The SDCR, a number from 0 to 255, is divided by 255, and multiplied by the duty
cycle of the incoming PWM signal. The result is the duty cycle of the color-adjust string. The table is programmable
through the serial interface when values different from the defaults are desired.
Table 11-1. Temperature based duty cycle modification of the color-adjust string
Table 11-2. Temperature Look-Up Table Defaults
(1)
Part
COLOR-ADJUST DUTY CYCL
TEMPERATURE ADJUSTMENT
Limits
MSL2021
SDCRxx = VALUE IN LOOK-UP TABLE 0x00 THRU 0x1F
SDCRxx = 0xFF RETURNS 100% OF THE PWM DUTY CYCLE
SDCRxx = 0x00 RETURNS 0% OF THE PWM DUTY CYCLE
Temperature (°C)
Register Multiplication factor
Address Name Default Value
18 0x00 SDCR18 0x4C 0.300
20 0x01 SDCR20 0x4D 0.303
22 0x02 SDCR22 0x4E 0.307
24 0x03 SDCR24 0x4F 0.311
26 0x04 SDCR26 0x50 0.314
28 0x05 SDCR28 0x51 0.318
30 0x06 SDCR30 0x52 0.322
32 0x07 SDCR32 0x53 0.327
34 0x08 SDCR34 0x54 0.331
36 0x09 SDCR36 0x55 0.336
38 0x0A SDCR38 0x56 0.340
40 0x0B SDCR40 0x58 0.345
42 0x0C SDCR42 0x59 0.350
44 0x0D SDCR44 0x5A 0.355
46 0x0E SDCR46 0x5C 0.361
48 0x0F SDCR48 0x5D 0.367
50 0x10 SDCR50 0x5E 0.373
52 0x11 SDCR52 0x60 0.379
54 0x12 SDCR54 0x62 0.385
56 0x13 SDCR56 0x63 0.392
58 0x14 SDCR58 0x65 0.399
DC
CA
SDCRxx
255
--------------------- -
DC
PWM
=
SDCRxx
255
--------------------- -