D-31M Datasheet, PDF (3/7 Pages) Roithner LaserTechnik GmbH – Driver for MID-IR LEDs

6. Mode Description
Driver provides two modes of operation: Quasi Continuous Wave (quasi steady-state) mode and
Pulse mode.
6.1. Quasi continuous wave (QCW) mode
The oscillating mode of symmetrical unipolar meander (fig.2.)
Such mode provides maximum average optical power from the LED. The LED current in this mode
can be changed in the range from 20 to 250 mA by using the multiposition switch for adjusting the
LED current (12). Using the button 5 one of four frequencies (512 Hz, 2 kHz, 8 kHz and 16 kHz)
can be selected. The pulse duration will be respectively equal 1000 µs, 250 µs, 62 µs and 31 µs.
Fehler!
f=0,5-16 kHz
31-1000 µs
20-250 mА
31-1000 µs
Fig.2. Current-time relation in case of continuous wave mode.
6.2. Pulse mode
The oscillating mode of pulse sequence (fig.3)
Such mode provides maximum peak optical power from the LED. Similarly to the quasi continuous
wave mode, by adjusting the switch 12 the LED current can be changed, but in the wider range:
from 0,1 to 2,0 A. Using the button 5 one of four frequencies (512 Hz, 2 kHz, 8 kHz and 16 kHz)
can be selected. Pulse duration can be also selected in the range from 0.6 to 20 µs with the help of
switch 3.
f=0,5-16 kHz
0,6 -20 µs
0-2 А
62-2000 µs
Fig.2. Current-time relation in case of pulse mode.
Note! Please, don’t use the combination of frequency and pulse duration that gives a duty cycle
more than 10 percents (table 1).
Note! We recommend to use the pulse current amount to 2 A only at pulse duration less than 1
µs. Otherwise used LED can be broken.
09.07.2012
D-31M
3 of 7