Wavelength Electronics WHS302, Datasheet And Operating Manual

Page: 13 / 28

© 2018 www.teamWavelength.com 13
WLD SERIES LASER DIODE DRIVERS
CONNECTION DIAGRAMS FOR TYPE A/B LASERS
VALUE DETAILS VALUE DETAILS
V
SET
Eq. (9) or (10) on page 15 R
LIM
Eq. (7) on page 11
IMON Eq. (11) on page 15 R
SENSE
Eq. (3) or (4) on page 10
PMON Eq. (13) on page 15 R
PD
Eq. (8) on page 12
Constant Current:
1
2
3
4
5
6
7
14
13
12
11
10
9
8
WLD3343
LASER
DIODE
DRIVER
VDD
R
LIM
1 TIE GROUND CONNECTIONS DIRECTLY TO PIN 7
R
SENSE
ENABLE
DISABLE
IMON
NC
1 k Ω
1
1
1
LD
PD LD PD
OR
VDD
D/A
OR OR
Bandgap
Voltage
Reference
V
SET
1
1
R
PD
I
PD
= V
PD
+
-
V
PD
R
PD
2k
Part # LM4040
www.national.com
1k
LDMAX
SENSE
I
00 . 1
R
With Eval Board (Rev. Level)
Without Evaluation Board
=
V
SET
= (Desired I
LD
) * (2*R
SENSE
)
LD Range R
SENSE
(Rev. C)
2.0 A
200 mA
438 m Ω
5.01
Ω
R
SENSE
(Rev. A&B)
500 m Ω
5.1
Ω
Figure 8. Type A/B laser configured for Constant Current operation.
Constant Power:
1
2
3
4
5
6
7
14
13
12
11
10
9
8
WLD3343
LASER
DIODE
DRIVER
VDD
R
PD
R
LIM
1
TIE GROUND CONNECTIONS DIRECTLY TO PIN 7
R
SENSE
ENABLE
DISABLE
IMON
PMON
0.1 µ F
1
1
1
LD
PD LD PD
OR
VDD
D/A
OR OR
Bandgap
Voltage
Reference
V
SET
1
2k
www.national.com
Part #LM4040
1k
PDMAX
PD
I
1
R
With Evaluation Board
Without Evaluation Board
=
V
SET
= (Desired I
PD
) * (2*R
PD
)
PD Range R
PD
2.0 mA
200 µ A
499
Ω
4.99 k Ω
LDMAX
SENSE
I
25 . 1
R
With Eval Board (Rev. Level)
Without Evaluation Board
=
LD Range R
SENSE
(Rev. C)
2.0 A
200 mA
438 m Ω
5.01 Ω
R
SENSE
(Rev. A&B)
500 m Ω
5.1 Ω
Figure 9. Type A/B laser configured for Constant Power operation.
Use the online WLD Circuit
Calculator to automatically
determine values for external
components.
www.teamwavelength.com/
support/design-tools/wld-
calculator/
Type A Laser Diode
Common
Cathode
Laser Diode Anode &
Photodiode Cathode Common
Type B Laser Diode
Isolated Photodiode
Short the
Laser Diode Anode
to Photodiode Cathode