DELAYED / SLOW START
Once power is applied, current at the attenuated level will flow
(~10 µA when configured for 250 mA max). After 100 msec,
current will rise to the level dictated by the setpoint voltage
at the rate of about 15 mA / msec. This delay ensures that
all control electronics are functioning before significant
current flows to the laser diode. The delay time is set with
internal components. [It can be increased - please request a
modification through Sales.] Refer to
for a typical
sequence.
CURRENT LIMIT
To set current limits, use the circuit below from the FL591
schematic. To set two current limits (one for each individual
driver), use the same circuit to also connect to VSET2.
CONSTANT POWER MODE
To operate in Constant Power mode with photodiode
feedback, use the circuit below from the FL591 schematic.
PDA1
PDR1
R10
1.0K
1.0K
R7
1.0K
R2
R3
1.0K
1.0K
1.0K
U1A
VS-U1
VEE-U1
AD8032
PMON1
PSET1
R4
R6
1.0K
1.0K
100K
0.012µF
VCC-U3
VEE-U3
PDFB1
AD8032
R9
C4
0.022µF
2
3
4
8
1
C1
R1
2
3
4
8
1
Figure 10. Typical Delayed / Slow Start Response
D8
LM4040-2.5
5
4
3
Q4A
2
1
6
Q4B
MMDT3946
R84
249
2
3
1
W
CW
CCW
R82
2.0K
C46
10uF
C47
10uF
R81
182
VCC
2
3
1
8
4
U4A
AD8032
2
3
1
8
4
U6A
AD8032
VCC-U4
VCC-U6
VEE-U6
R78
1.05K
VCC
R61
10.0
VCC
1
GND
2
RST
3
VSET1
4
GND
5
VSET2
6
LDC2
LDC2
PGND
PGND
LDC1
LDC1
U5
FL500
C26
10uF
C48
10uF
D7
1N4148
VSET1
R77
1.0K
R76
1.0K
R85
1.0K
R75
1.0K
R83
1.0K
R86
2.0K
TP2
LIM1
© 2020
10
FL500 LASER DIODE DRIVER
