AN2827

Examples of register setup for each mode

Doc ID 15047 Rev 1

23/30

8

Examples of register setup for each mode

8.1

Example 1: 400 mA flash with 700 ms duration

The value of FDIM (4 bits) must be set to 0x7 to set-up the current source to the chosen

value (Table 11).

The flash duration timer can be set from 100 ms up to 1500 ms in 100 ms steps. If the

desired flash duration is 700 ms the FTIM value (4 bits) must be se to 0x7.

The PWR_ON bit of the command register must be set to 1.

The TRIG_EN bit of the command register must be set to 1.

The TCH_ON bit of the command register must be set to 0.

The NTC_ON bit of the command register can be set to any value because NTC is

automatically ON when the flash mode is active. Setting this bit to 0 will not switch off the

NTC.

Four bytes must be written to the STCF05 to make a flash.

Table 11.

Torch and flash mode dimming register settings

LDIM (hex)

0

1

2

3

4

5

6

7

8

9

A

B

C

TDIM (hex)

0

1

2

3

4

5

6

7

FDIM(hex)

0

1

2

3

4

5

6

7

LED current [mA]

15

20

30

45

60

75

90

120

160

200

240

320

400

Internal step

12

34

56

78

9

10

11

12

13

Table 12.

COMMAND register data to enter flash mode

CMD_REG

PWR_ON

TRIG_EN

TCH_ON

NTC_ON

FTIM_3

FTIM_2

FTIM_1

FTIM_0

11

x

X

0111

MSB

LSB

Table 13.

DIMMING register data for flash mode

DIM_REG

N/A

TDIM_2

TDIM_1

TDIM_0

N/A

FDIM_2

FDIM_1

FDIM_0

0000

0111

MSB

LSB

Table 14.

I²C data packet for activating flash mode

Byte

Hex

Binary

Comment

1

62

01100010

Device address + R/W bit

2

00

00000000

Command register address

3

D7

11010111

Data of the command register

4

07

00000111

Data of the dimming register