STP1612PW05
Setting output current
Doc ID 15819 Rev 4
21/35
11
Setting output current
The output current (I
OUT
) is set by an external resistor, R
ext
.
It is calculated from the equation:
V
R-EXT
= 1.24 x G; I
OUT
= (V
R-EXT
/R
ext
) x 560
Whereas R
ext
is the resistance of the external resistor connected to R-EXT terminal
and V
R-EXT
is its voltage. G is the digital current gain, which is set by the bit9 – bit2 of the
configuration register. The default value of G is 1. For your information, the output current is
about 20 mA when R
ext
= 34.70 k
Ω
and 10 mA when R
ext
= 69.6 k
Ω
if G is set to
default value 1. The formula and setting for G are described in next section.
Figure 12.
Rext vs output current
Table 15.
Rext vs output current
(1)
1.
T
A
= 25 °C, V
dd
= 3.3 V; 5.0 V, V
Led
= 3.0 V, V
drop
= 1.5 V, HC = 0101011 (default)
Iout (mA)
Rext (k
Ω
)
3
238.2
5
142.2
10
69.6
20
34.70
30
22.94
50
13.72
60
11.40
80
8.63
0
25
50
75
100
125
150
175
200
225
250
275
3
5
10
20
30
50
60
80
Iout (mA)
Re
xt
(
kO
hm
)
Содержание STP1612PW05
Страница 3: ...STP1612PW05 Contents Doc ID 15819 Rev 4 3 35 16 Package mechanical data 25 17 Revision history 34...
Страница 28: ...Package mechanical data STP1612PW05 28 35 Doc ID 15819 Rev 4 Figure 17 SO 24 package dimensions...
Страница 32: ...Package mechanical data STP1612PW05 32 35 Doc ID 15819 Rev 4 Figure 20 QFN24 4x4 mechanical drawing...
