Output wiring example: LED Driving
LED can be driven directly by camera digital output. A series resistor must be used to limit LED current.
Figure 24: LED driving
LED series resistor can be calculated by the following equation:
R
=
V
PSU
−
V
output
−
V
LED
I
LED
,
where:
V
PSU
is power supply voltage (5 V to 24 V),
V
output
is voltage across digital output pins (see.
Optically isolated digital output
V
LED
is LED forward voltage (see table below),
I
LED
is LED current.
Remember to use the appropriate resistor power rating:
P
(
RES
) =
I
2
LED
×
R
= (
V
PSU
−
V
LED
)
×
I
LED
Typical LED forward voltage:
LED Colour
V
LED
(typ.)
V
LED
(max.)
Note
Standard Red
1.7 V
2.1 V
-
Super Bright Red
1.85 V
2.5 V
-
Low power Red
1.7 V
2.0 V
-
Orange
2.0 V
2.1 V
-
Yellow
2.1 V
2.2 V
-
Green
1.9 V
2.5 V
-
Emerald Green
2.1 V
2.7 V
-
Blue
2.5 V
3.7 V
-
White
2.8 V
3.8 V
-
Infra-Red
1.3 V
1.8 V
Opto coupler
Table 23: digital output, LED driving
XIMEA Technical Manual, Version: v230927
35
