iC-WKN
15V CW LASER DIODE DRIVER
Rev A1, Page 1/7
SO8tp
FEATURES
APPLICATIONS
CW operation up to 300 mA from 2.4..15 V supply voltage
Rapid soft start after power-on typical within 70 s
Optimised for N-type laser diodes
Simple power adjustment via the external resistor
Control loop accuracy better than 1.5 % with changes in
temperature, supply voltage and load current
Integrated reverse polarity protection for the iC and laser
diode
Strong suppression of transients with very small external
capacitors; integrated flyback path
Permanent shutdown with excessive temperature and
overcurrent (i.e. if the laser diode is damaged or the
feedback current path fails)
Two feedback inputs permit all current LD types to be used
(M/P/N configurations)
Modulation via the feedback inputs is possible
Wide monitor current range from 2.5 A to 6.25 mA
LD modules
Blue laser diodes
PACKAGES
BLOCK DIAGRAM
Copyright 2003, iC-Haus
www.ichaus.com
MD
LD
MD LD
MD
0.5 V
VREF
..47 nF..
OVER TEMP.
TRANSIENT
iC-WKN
OVER CURRENT/
LD
..100 nF..
CI
R
..1 F..
CLDA
LD
AGND
CVCC
MD
LDK
MDK
CI
MDA
NQ
LDA
GND
GND
VCC
+2.4..+15 V
5
1
3
4
2
8
7
0..3
RM
6
PROTECTION
+
-
D
1
FEEDBACK MON.
80..200 k
RGND
47 pF
CM
suitable laser diode configurations: N, P, M
iC-WKN
15V CW LASER DIODE DRIVER
Rev A1, Page 2/7
DESCRIPTION
iC-WKN is a driver for laser diodes in continuous wave operation with laser currents of up to 300 mA, which
requires only four external components. The wide power supply range of up to 15 V allows for operation of
blue laser diodes.
The iC includes integrated circuitry protecting against destruction by ESD, excessive temperature and over-
current plus a soft start of the regulator to protect the laser diode when the power supply is switched on. The
iC also filters the laser diode power supply for transients.
The regulator is adapted to the laser diode by an external resistor at MDA. The monitor current acts as a
reference and is regulated independent of the influence of temperature and supply voltage (range: 2.5 A to
6.25 mA). The capacitor at CI determines the control time constants and start-up time.
A second monitor input, pin MDK, allows the driver to be used for other types of laser diode configuration;
alternatively, it can be used as an analog modulation input (DC to a few kHz).
In the event of failure, such as overcurrent in the laser path with a lack of feedback, for example, a quick
power lockout is activated. The shutdown persists until power is reapplied, permitting a restart. The strain on
power packs and batteries is relieved and the laser class is retained even in the event of a disturbance.
iC-WKN offers additional protection by means of spike detection at pin MDA. Should spikes or oscillation
occur at pin MDA the power lockout is activated after a time-out.
PACKAGES SO8tp to JEDEC Standard
PIN CONFIGURATION SO8tp
PIN FUNCTIONS
(top view)
No. Name Function
1
GND
Ground
2
CI
Capacitance for Power Control
3
AGND Reference Ground for CI, RM
4
MDK
Monitor Input 2
(MD Cathode, modulation)
5
MDA
APC Setup, Monitor Input 1
(MD Anode)
6
VCC
+2.4 .. +15 V Supply Voltage
7
LDA
Laser Supply (LD Anode)
8
LDK
Driver Output (LD Cathode)
iC-WKN
15V CW LASER DIODE DRIVER
Rev A1, Page 3/7
All voltages are referenced to ground unless otherwise noted.
All currents into the device pins are positive; all currents out of the device pins are negative.
ABSOLUTE MAXIMUM RATINGS
Beyond these values damage may occur; device operation is not guaranteed.
Item Symbol
Parameter
Conditions
Fig.
Unit
Min.
Max.
G001 VCC
Voltage at VCC
-6
16
V
G002 I(VCC)
Current in VCC
-10
900
mA
G003 I(CI)
Current in CI
-10
10
mA
G004 I(LDA)
Current in LDA
-900
10
mA
G005 I(LDK) Current
in
LDK
-10
900
mA
G006 I(MDA) Current
in
MDA
-10
10
mA
G007 I(MDK)
Current in MDK
-10
10
mA
G008 I(AGMD) Current in AGND
-10
10
mA
G009 I(GND)
Current in GND
-900
10
mA
E001 Vd()
ESD Susceptibility at all pins
MIL-STD-883, Method 3015, HBM
100 pF discharged through 1.5 k
2
kV
TG1 Tj
Operating Junction Temperature
-40
150
C
TG2 Tj
Storage Temperature Range
-40
150
C
THERMAL DATA
Operating Conditions: VCC = 2.4..15 V
Item Symbol
Parameter
Conditions
Fig.
Unit
Min.
Typ.
Max.
T1
Ta
Operating Ambient Temperature
Range
-40
85
C
T2
Rthja
Thermal Resistance Chip/Ambient
soldered to PCB,
no additional cooling areas
therm. pad soldered to approx. 2cm
cooling area
30
170
50
K/W
iC-WKN
15V CW LASER DIODE DRIVER
Rev A1, Page 4/7
ELECTRICAL CHARACTERISTICS
Operating Conditions: VCC = 2.4..15 V, RM = 80 ..200 k, Tj = -40..125 C unless otherwise noted
Item
Symbol
Parameter
Conditions
Tj
Fig.
Unit
C
Min.
Typ.
Max.
Total Device
001 VCC
Permissible Supply Voltage
2.4
15
V
002 I(LDK)m Permissible Laser Drive Current
power control range
10
300
mA
003 Idc(VCC) Supply Current
without load path
closed control loop,
I(MDK) = 0, I(LDK) = 290 mA
10
20
mA
004 Ioff(VCC) Supply Current on Reset
2.4
5
mA
005 Ir(VCC)
Reverse Supply Current
RM= 50 k, VCC = -6 V
-6
mA
006 ton()
Turn-on Delay
VCC: 0 5 V to 95 % I(LDK),
I(LDK) = I(LDK)m;
CI = 47 nF
CI = 100 nF
70
150
s
s
007 Vc()hi
Clamp Voltage hi at VCC, LDA
I()= 10mA, other pins open
16
24
V
008 Vc()hi
Clamp Voltage hi at LDK
V()< VCC + 1 V; I() = 10 mA,
other pins open
16
24
V
009 Vc()hi
Clamp Voltage hi at MDK vs. LDA I()= 10mA, other pins open
8
1
V
010 Vc()hi
Clamp Voltage hi at MDA, CI
I() = 10 mA, other pins open
1.1
4
V
011 Vc()lo
Clamp Voltage lo at
VCC, LDA, MDK, MDA, CI
I() = -10 mA, other pins open
-9
V
Reference and Monitor Inputs MDA, MDK, AGND
101 V(MDA)
Reference Voltage at MDA
closed control loop,
V(LDK) > Vs(LDK)
480
500
520
mV
102 dV(MDA) Reference Voltage Temperature
Drift at MDA
see 101
120
V/C
103 Ierr(MDA) Input Current in MDA
closed control loop,
I(MDK) = 0, I(LDK) = 10..290 mA
-100
100
nA
104 dI(MDA) Input Current Temperature Drift
in MDA
see 103
-1
1
nA/C
105 APCerr
Control Error
RM = 10 k, Tj = 0..80 C
RM = 10 k, Tj = -40..125 C
0.3
1
%
%
106 dI(RM)
Supply Voltage Suppression
V(VCC): 2.4 15 V,
I(LDK) = 290 mA
-0.2
0.2
%/V
107 Rgnd()
Resistor AGND-GND
3
301 Vf(MDK) Voltage at MDK
Vf() = V(LDA) - V(MDK);
I(MDK) = 1 A..1 mA
0.46
2
V
302 CR()
Current Ratio I(MDA)/I(MDK)
I(MDK) = 1 A..1 mA
I(MDK) = 1..6 mA
0.98
0.95
1.02
1.05
303 TC()
Current Ratio Temperature
Coefficient I(MDA)/I(MDK)
I(MDK) = 1 A..1 mA
I(MDK) = 1..6 mA
-0.005
-0.025
0.005
0.025
%/C
%/C
Laser Driver LDA, LDK
201 Vs(LDK) Saturation Voltage at LDK
I(LDK) = 40 mA
I(LDK) = 290 mA
350
700
mV
mV
202 dI(LD)
Load Balancing Error
I(LD) = 20 mA,
I(LDK): 20 mA 290 mA
-1.5
1.5
%
203 It(LDK)
Overcurrent Threshold in LDK
V(LDK) = 2..5.5 V
300
700
mA
203 It(LDK)m Maximum Overcurrent Threshold
in LDK
1.2
A
204 toff()
Overcurrent Reset Delay
lack of feedback:
I(MD) = 0 bis I(LDK) = It(LDK);
CI = 47 nF
CI = 100 nF
85
170
s
s
205 Vf()
Flyback Diode Forward Voltage
LDK-LDA
I(LDK) < 290 mA
1.3
V
iC-WKN
15V CW LASER DIODE DRIVER
Rev A1, Page 5/7
ELECTRICAL CHARACTERISTICS
Operating Conditions: VCC = 2.4..15 V, RM = 80 ..200 k, Tj = -40..125 C unless otherwise noted
Item
Symbol
Parameter
Conditions
Tj
Fig.
Unit
C
Min.
Typ.
Max.
206 Rvcc()
Transient Protection Resistor
VCC to LDA
1.3
207 Vt(MDA) Shutdown Threshold at MDA
t > 1 s
0.7
2
V
Control Release Flip-Flop
401 VCCen
Set Threshold for Enable
Flip-Flop
-40
27
125
0.6
1.2
1
0.6
1.9
1.9
1.7
1.2
V
402 Toff
Overtemperature Shutdown
140
165
C
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