STCF04TBR Datasheet, PDF (26/43 Pages) STMicroelectronics – High power white LED SuperCap™ driver with I²C interface

Description of the internal registers
STCF04
Table 16. Auxiliary LED timing table
AUXT (hex) 0 1 2 3 4 5 6 7 8 9 A B C D E F
AUX LED
time [s]
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9
1
1.1 1.2 1.3 1.4 ∞
9.4
Status (STAT_REG) 03(hex)
Table 17. Status register
STAT_REG
(Read mode)
MSB
LSB
SUB ADD=03
N/A F_RUN FL_R NTC_W NTC_H OT_F FL_OVR
LTH
Power-ON, Shutdown
mode RESET value
0
0
0
0
0
0
0
0
F_RUN: this bit is kept HIGH by the STCF04 during Flash mode. By checking this bit, the
microprocessor can verify if the Flash mode is running or has been terminated by the time
counter.
FL_R: (FLASH ready) this bit is set to 0 if the SuperCap voltage is not high enough to make
a flash.
NTC_W: this bit is set HIGH by the STCF04 and the ATN pin is pulled down, when the
voltage seen on the pin R_X exceeds V_REF4 = 0.56 V. This threshold corresponds to a
warning temperature value at the LED measured by the NTC. The device is still operating,
but a warning is sent to the microprocessor. This bit stays high until the temperature goes
below the threshold.
NTC_H: this bit is set HIGH by the STCF04 and the ATN pin is pulled down, when the
voltage seen on the pin R_X exceeds V_REF5 = 1.2 V. This threshold corresponds to an excess
temperature value at the LED measured by the NTC. The device is put into Idle mode to
avoid damaging the LED. This bit is reset by the STCF04 following a read operation of the
STAT_REG.
OT_F: this bit is set HIGH by the STCF04 and the ATN pin is pulled down, when the chip
overtemperature protection (~140 °C) has put the device into Idle mode. This bit is reset by
the STCF04 following a read operation of the STAT_REG.
FL_OVR: this bit is set HIGH, if the flash operation is terminated by the light sensor.
LTH: this bit is set HIGH when the local temperature protection for the SuperCap charging
circuit is activated.
26/43
Doc ID 022927 Rev 3