STCF06 Datasheet, PDF (24/33 Pages) STMicroelectronics – 1.5 A white LED driver with I²C interface

Description of internal registers
STCF06
Table 12. Auxiliary register
AUX_REG
(write mode)
MSB
SUB ADD=02
AUXI_3
Power-ON,
0
SHUTDOWN MODE
RESET Value
AUXI_2
0
AUXI_1
0
LSB
AUXI_0 AUXT_3 AUXT_2 AUXT_1 AUXT_0
0
0
0
0
0
9.8
AUXI_0~3
This 4 bits register defines the AUX LED current from 0 to 20 mA. See AUX LED Dimming
Table for reference. Loading any value between 1 and 15 also starts the AUX LED current
source timer, if enabled. The AUX LED current source is active only in Ready mode, and is
deactivated in any other mode.
9.9
AUXT_0~3
This 4 bit register controls the timer that defines the ON-time of the AUX LED current
source. ON-time starts when the AUXI register is loaded with any value other than zero, and
stops after the time defined in the AUXT register. Values from 1 to 14 of the AUXT register
correspond to an ON-time of the AUX LED ranging from 100 to 1400 ms in 100 ms steps.
The value 15 puts the AUX LED to the continuous light mode. The activation/deactivation of
the AUX LED current source is controlled using only the AUXI register.
Table 13. Auxiliary LED dimming table ⁽¹⁾
AUXI (hex) 0 1 2 3 4 5 6 7 8 9 A B C D E F
AUX LED 0.0 1.3 2.6 4.0 5.3 6.6 8.0 9.3 10.6 12.0 13.3 14.6 16.0 17.3 18.6 20.0
current [mA]
1. 20 mA output current is achievable only if the supply voltage is higher than 3.3 V.
Table 14. Torch mode and flash mode dimming registers settings
T_DIM 0 1 2 3 4 5 6 7 8 9 A B C D E F
(hex)
F_DIM
(hex)
0 1 2 3 4 5 6 7 8 9ABC D
E
F
LED 28 34 40 48 58 69 83 98 116 139 165 197 220 266 313 373 446 526 633 753 893 1066 1266 1513
current
[mA]
Internal 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
step
V_REF1 33 40 47 56 67 80 95 113 134 160 190 227 33 40 47 56 67 79 95 113 134 160 190 227
[mV]
Sense R_FL R_FL R_FL R_FL R_FL R_FL R_FL R_FL R_FL R_FL R_FL R_FL R_FL R_FL R_FL R_FL R_FL R_FL R_FL R_FL R_FL R_FL R_FL R_FL
Resist. _{+ + + + + + + + + + + +}
R_TR R_TR R_TR R_TR R_TR R_TR R_TR R_TR R_TR R_TR R_TR R_TR
Note:
LED current values refer to R_FL = 0.15 Ω, R_TR = 1 Ω.
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