THORLABS IP250-BV, Руководство пользователя

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IP250-BV Blue Laser Diode Controller Chapter 4: Output Derating Curves
Rev F, October 24, 2017 Page 11
Chapter 4 Output Derating Curves
Since the IP250 is intended for use with blue or blue – violet laser diodes it is
optimized to operate with lasers that develop >5 V of load voltage (V
OP
). The power
dissipation of the main laser drive transistor is rated at 1.75 W. This rating is
maintained at full output current (250 mA) for any load voltage above 5 V when
powering the unit from a ±12 V power supply.
It is possible to operate with lasers with less than 5 V V
OP
, but the output current
must be derated to maintain a safe operating area for the drive transistor.
To determine the power dissipation of the drive transistor use the following formula:
ܲ ൌ ܫ
௢௨௧௣௨௧
ሺܸ
௜௡
െ ܸ
ை௉
ሻ
Where:
V
in
is the positive input voltage to the driver (typically 10 to 12 V).
V
OP
is the operating voltage of the laser diode.
I
output
is the output current to the laser.
The following curve is provided for quick reference.
Figure 4 Derating Curve
0.00
0.05
0.10
0.15
0.20
0.25
0.30
1 2 3 4 5 6 7 8
Output Curre
nt
Laser V
op
Derating Curve (12 V Input)