Registers description

STCF05

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Doc ID 15257 Rev 4

9.13

LED_O

during a torch or flash operation. This condition can be caused by an open LED, indicating a

LED failure. The device automatically goes into ready mode to avoid damage. Internal high

frequency filtering avoids false detections. This bit is reset by the STCF05 following a read

operation of the STAT_REG.

9.14

NTC_W

This bit is set HIGH by the STCF05 and the ATN pin is pulled down, when the voltage seen

value at the LED measured by the NTC. The device is still operating, but a warning is sent to

the microprocessor. This bit is reset by the STCF05 following a read operation of the

STAT_REG.

9.15

NTC_H

This bit is set HIGH by the STCF05 and the ATN pin is pulled down, when the voltage seen

value at the LED measured by the NTC. The device is put in ready mode to avoid damaging

the LED. This bit is reset by the STCF05 following a read operation of the STAT_REG.

9.16

OT_F

This bit is set HIGH by the STCF05 and the ATN pin is pulled down, when the chip over-

temperature protection (~140 °C) has put the device in ready mode. This bit is reset by the

STCF05 following a read operation of the STAT_REG.

9.17

OC_F

This bit is set high by the STCF05 when the max peak inductor current threshold is reached

(3 A programmable #). The OC_F bit is not latched into the STATUS reg. and the ATN pin

remains HIGH.

9.18

VOUTOK_N

This bit is set by the STCF05. It is used to protect the device, if the output is shorted. The

VOUTOK_N bit is set to HIGH at the start-up. Then a current generator of 20 mA charges

the output capacitor for 360 µs typ. and it detects when the output capacitor reaches 100

mV. If this threshold is reached the bit is set to LOW. If the output is shorted to ground or the

LED is shorted, this threshold is never reached: the bit stays HIGH, ATN pin is pulled down

and the device will not start. This bit is reset following a read operation of the STAT_REG.