STP1612PW05QTR STMicroelectronics, STP1612PW05QTR Datasheet - Page 21

• Manufacturer Part Number: STP1612PW05QTR
• Description: 16-channel Led Driver With 16-bit Pwm, 8-bit Gain And Full Led Error Detection
• Manufacturer: STMicroelectronics

STP1612PW05
11
Setting output current
The output current (I
It is calculated from the equation:
V
Whereas R
and V
configuration register. The default value of G is 1. For your information, the output current is
about 20 mA when R
default value 1. The formula and setting for G are described in next section.
Figure 12. Rext vs output current
Table 15.
1. T
R-EXT
A
= 25 °C, V
R-EXT
= 1.24 x G; I
ext
is its voltage. G is the digital current gain, which is set by the bit9 – bit2 of the
Rext vs output current
dd
is the resistance of the external resistor connected to R-EXT terminal
= 3.3 V; 5.0 V, V
Iout (mA)
275
250
225
200
175
150
125
100
OUT
75
50
25
OUT
ext
0
10
20
30
50
60
80
3
5
3
= (V
= 34.70 kΩ and 10 mA when R
) is set by an external resistor, R
R-EXT
Led
Doc ID 15819 Rev 2
5
= 3.0 V, V
/R
ext
(1)
10
) x 15.5
drop
= 1.5 V, HC = 0101011 (default)
20
Iout (mA)
30
ext
ext
= 69.6 kΩ if G is set to
.
50
Rext (kΩ)
238.2
142.2
34.70
22.94
13.72
11.40
69.6
8.63
60
Setting output current
80
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