STCF06TBR Datasheet STCF06TBR | P25-P27

STCF06 Description of internal registers

Doc ID 14549 Rev 3 25/35

Note: LED current values refer to R

= 0.15 Ω, R

= 1.0 Ω

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.

Figure 12. Flash and torch current vs. dimming value

200

400

600

800

1000

1200

1400

1600

024681012141618

dimming value

ILED [mA]

Torch current Flash current

200

400

600

800

1000

1200

1400

1600

024681012141618

dimming value

ILED [mA]

Torch current Flash current

Table 12. Auxiliary register

AUX_REG

(write mode)

MSB LSB

SUB ADD=02 AUXI_3 AUXI_2 AUXI_1 AUXI_0 AUXT_3 AUXT_2 AUXT_1 AUXT_0

Power-ON,

SHUTDOWN MODE

RESET Value

00 000 000

Obsolete Product(s) - Obsolete Product(s)

Description of internal registers STCF06

26/35 Doc ID 14549 Rev 3

Note: LED current values refer to R

= 0.15 Ω, R

= 1 Ω.

9.10 F_RUN

This bit is kept HIGH by the STCF06 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.

9.11 LED_F

This bit is set by the STCF06 when the voltage seen on the VOUT pin is V

REF2

> 5.3 V

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 STCF06 following a read

operation of the STAT_REG.

Table 13. Auxiliary LED dimming table

(1)

AUXI (hex) 0123456789ABCDEF

AUX LED

current [mA]

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

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

(hex)

0 1 2 3 4 5 6 7 8 9 A B C D E F

F_DIM

(hex)

0 1 2 3 4 5 6 7 8 9 A B C D E F

LED

current

[mA]

28 34 40 48 58 69 83 98 116 139 165 197 220 266 313 373 446 526 633 753 893 1066 1266 1513

Internal

step

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

REF1

[mV]

33 40 47 56 67 80 95 113 134 160 190 227 33 40 47 56 67 79 95 113 134 160 190 227

Sense

Resist.

Table 15. Status register

STAT_REG

(read mode)

MSB LSB

SUB ADD=03 N/A F_RUN LED_F NTC_W NTC_H OT_F N/A VOUTOK_N

Power-ON,

SHUTDOWN MODE

RESET Value

0000000 0

Obsolete Product(s) - Obsolete Product(s)

STCF06 Description of internal registers

Doc ID 14549 Rev 3 27/35

9.12 NTC_W

This bit is set HIGH by the STCF06 and the ATN pin is pulled down, when the voltage seen

on the pin R

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 is reset by the STCF06 following a read operation of the

STAT_REG.

9.13 NTC_H

This bit is set HIGH by the STCF06 and the ATN pin is pulled down, when the voltage seen

on the pin R

exceeds V

REF5

. This threshold (1.2 V) corresponds to an excess temperature

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 STCF06 following a read operation of the STAT_REG.

9.14 OT_F

This bit is set HIGH by the STCF06 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

STCF06 following a read operation of the STAT_REG.

9.15 VOUTOK_N

This bit is set by the STCF06. 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.

Figure 13. VOUTOK_N behavior

Obsolete Product(s) - Obsolete Product(s)

P1-P3 P4-P6 P7-P9 P10-P12 P13-P15 P16-P18 P19-P21 P22-P24 P25-P27 P28-P30 P31-P33 P34-P35

STCF06TBR

Mfr. #:

Buy STCF06TBR

Manufacturer:

STMicroelectronics

Description:

LED Lighting Drivers 1.5A WHITE LED DRVR

Lifecycle:

New from this manufacturer.

Delivery:

DHL FedEx Ups TNT EMS

Payment:

T/T Paypal Visa MoneyGram Western Union

Products related to this Datasheet

STCF06TBR