STCF03I_08 Datasheet, PDF (14/33 Pages) STMicroelectronics – High power white LED driver with I²C interface

Introduction
STCF03I
7.2.4
ADD pin
With this pin it is possible to select one of the 4 possible I²C slave addresses. No internal
pull-up nor pull-down is provided. The pin has to be connected to either GND, V_I, SCL or
SDA to select the desired I²C slave address (see Table 7)
Table 7. Address table
ADD pin
A7
A6
A5
A4
A3
A2
A1
A0
GND
0
1
1
0
0
0
0
R/W
VBAT
0
1
1
0
0
0
1
R/W
SDAL
0
1
1
0
0
1
0
R/W
SCL
0
1
1
0
0
1
1
R/W
Figure 4.
When ADD is connected to GND the I²C address is assigned automatically while in the
other three configurations in which ADD pin is connected to VBAT or SDA or SCL, the
following procedure must be activated in order that the right address is assigned.
After applying VBAT to the chip, the VBAT voltage must be pulled down to GND for a time
longer than 100 ms. After that time the right I²C address is assigned to the chip. This
procedure must be repeated every time the VBAT voltage is disconnected (see Figure 4
below).
Procedure for assigning a non-default I²C address
100ms
VBAT
Address is assigned.
The new I²C address
can be used for SCL
and SDA
….
SCL LINE
S
T
A
R
T
DEVICE
ADDRESS
7 bits
W
R
I
T
E
ADDRESS OF
REGISTER
DATA
M
L R AM
L AM
S
LA
S
S / CS
SCS
T
SC
B
BWK B
BKB
O
BK
SDA LINE
P
7.2.5
14/33
TMSK pin
This pin can be used to implement the T_X masking function. This function has effect only for
flash current settings higher than 200 mA (bit FDIM_3=1). Under this condition, when this
pin is pulled high by the µP, the current flowing in the LED is forced at 200 mA typ. No
internal pull-up nor pull-down is provided; to be externally wired to GND if T_X masking
function is not used.