STCF03I_08 Datasheet, PDF (20/33 Pages) STMicroelectronics – High power white LED driver with I²C interface

Description of internal registers
8
Description of internal registers
STCF03I
Table 9. I²C register mapping function
Register name
SUB ADDRESS (hex)
CMD_REG
00
DIM_REG
01
AUX_REG
02
STAT_REG
03
Operation
R/W
R/W
R/W
R only
Table 10. Command register
CMD_REG
(write mode)
MSB
SUB ADD=00 PWR_ON TRIG_EN TCH_ON NTC_ON FTIM_3
Power ON
RESET Value
0
0
0
0
0
FTIM_2
0
FTIM_1
0
LSB
FTIM_0
0
8.1
PWR_ON
When set, it activates all analog and power internal blocks including the NTC supporting
circuit, and the device is ready to operate (ready mode). As long as PWR_ON=0, only the
I²C interface is active, minimizing Stand-by Mode power consumption.
8.2
TRIG_EN
This bit is AND-ed with the TRIG pin to generate the internal signal FL_ON that activates
flash mode. By this way, both soft-triggering and hard-triggering of the flash are made
possible. If soft-triggering (through I²C) is chosen, the TRIG pin is not used and must be
kept HIGH (VI). If hard-triggering is chosen, then the TRIG pin has to be connected to a µP
I/O devoted to flash timing control, and the TRIG_EN bit must be set in advance. Both
triggering modes can benefit of the internal flash time counter, that uses the TRIG_EN bit
and can work either as a safety shut-down timer or as a flash duration timer. Flash mode
can start only if PWR_ON=1. LED current is controlled by the value set by the FDIM_0~3 of
the DIM_REG.
8.3
TCH_ON
When set from ready mode, the STCF03I enters torch mode. The LED current is controlled
by the value set by the TDIM_0~3 of the DIM_REG.
8.4
20/33
NTC_ON
When the NTC_ON bit is set to HIGH and the device is in ready mode, then the comparators
that monitor the LED temperature are activated. NTC-related blocks are always active
regardless of this bit in torch mode and flash mode.