iC-HK
155MHz LASER SWITCH
Rev D1, Page 1/8
FEATURES
APPLICATIONS
Laser switch for frequencies from CW up to 155MHz
Spike-free switching of the laser current
Dual switching inputs with independent current control
Operates as a voltage-controlled current source
Pulsed operation with up to 700mA per channel
CW operation with up to 150mA per channel
Simple power control at pin CI
Control to the mean of the laser power in conjunction with
iC-WK (CW laser diode driver)
Supplement to iC-WK for pulsed operation
Thermal shutdown
Protection against ESD
Extended temperature range available as an option
Data transmission
Laser scanning devices
Optical storage devices
PACKAGES
SO8 MSOP8
thermal pad thermal pad
BLOCK DIAGRAM
2002
iC-Haus GmbH
Tel
+49-6135-9292-0
Integrated Circuits
Fax +49-6135-9292-192
Am Kuemmerling 18, D-55294 Bodenheim
http://www.ichaus.com
2
5
7
Suitable laser diode configurations:
N
LD
MD LD
MD
LD
OVERTEMP.-
SHUTDOWN
iC-HK
CI
LDK
EN1
EN2
AGND2
AGND1
GND
8
3
1
5
4
2
6
VDD
7
MD LD
RK1
RK2
CI
CLDA
RM
MD
M
P
M2
M1
LDA
MDA
CI
iC-WK
LD
Operation with constant
voltage (uncontrolled):
Operation in conjunction with
iC-WK (power controlled):
4
MDK
P
M/N
iC-HK
155MHz LASER SWITCH
Rev D1, Page 2/8
OVERTEMP.-
SHUTDOWN
iC-HK
CI
LDK
EN1
EN2
AGND2
AGND1
GND
8
3
1
5
4
2
6
VDD
7
LD
RK1
RK2
CLDA
M2
M1
+3.5..5V
V(CI)
Operation as a voltage-controlled current source
TRANSIENT
OVER CURRENT
R
AGND
LDK
MDK
CI
MDA
NQ
LDA
GND
VCC
PROTECTION
+
-
D
1
OVERTEMP.
iC-WK
FEEDBACK MON./
0.5V
VREF
LDK
VDD
EN1
EN2
AGND1
AGND2 GND
CI
Operation of iC-HK in conjunction with CW driver iC-WK (see application information for optional
parts/connections)
DESCRIPTION
Laser Switch iC-HK enables the spike-
free switching of laser diodes with well-
defined current pulses at frequencies
ranging from DC to 155MHz.
The diode current is determined by the
voltage at pin CI and by the resistors
RK1 and RK2. The two fast switches are
controlled independently via CMOS in-
puts EN1 and EN2. The laser diode can
thus be turned on and off or switched
between different current levels defined
by the ratio of RK1 and RK2.
Each channel can be operated on
150mA DC and up to 700mA pulsed
current depending on the frequency,
duty cycle and heat dissipation.
The integrated thermal shutdown fea-
ture prevents damage from excessive
temperature.
iC-HK supplements the laser diode
driver iC-WK which uses the monitor
current of the laser diode to control the
laser power. iC-WK therefore controls
the voltage at pin CI in such a way that the mean value of the emitted laser power is constant (APC), providing
there is a constant duty cycle and a switching frequency of greater than 100kHz.
iC-HK
155MHz LASER SWITCH
Rev D1, Page 3/8
PACKAGES SO8tp, MSOP8tp to JEDEC-Standard
PIN CONFIGURATION SO8tp (with thermal pad)
(top view)
PIN CONFIGURATION MSOP8tp 3mm (with thermal pad)
(top view)
PIN FUNCTIONS
No. Name
Function
1
EN1
Channel 1 Switching Input
2
AGND1
Channel 1 Reference Ground
3
LDK
Driver Output (LD Cathode)
4
AGND2
Channel 2 Reference Ground
5
EN2
Channel 2 Switching Input
6
GND
Ground
7
VDD
+5V Supply Voltage
8
CI
Voltage Reference for Current Control
iC-HK
155MHz LASER SWITCH
Rev D1, Page 4/8
All voltages are referenced to ground unless otherwise stated.
All currents into the device pins are positive; all currents out of the device are negative.
ABSOLUTE MAXIMUM RATINGS
Beyond these values damage may occur; operation of the device is not guaranteed.
Item
Symbol
Parameter
Conditions
Fig.
Unit
Min.
Max.
G001 VDD
Voltage at VDD
-0.7
6
V
G002 I(VDD)
Current in VDD
-10
150
mA
G003 V(CI)
Voltage at CI
-0.7
6
V
G004 I(LDK)
Current in LDK
DC current
-10
300
mA
G005 I(AGND1) Current in AGND1
DC current
-150
10
mA
G006 I(AGND2) Current in AGND2
DC current
-150
10
mA
G007 V()
Voltage at LDK, EN1, EN2, AGND1
and AGND2
-0.7
6
V
EG01 Vd()
Susceptibility to ESD at
all pins
Mil. Std. 883, Method 3015, HBM
100pF discharged through 1.5k
S
1
kV
TG01 Tj
Operating Junction Temperature
-40
150
C
TG02 Ts
Storage Temperature Range
-40
150
C
THERMAL DATA
Operating Conditions: VDD= 3.5..5.5V
Item
Symbol
Parameter
Conditions
Fig.
Unit
Min.
Typ.
Max.
T1
Ta
Operating Ambient Temperature
Range
(extended range on request)
-25
85
C
T1
Rthja
Thermal Resistance
Chip/Ambient (SO8)
soldered to PCB,
no additional cooling areas
therm. pad soldered to approx. 2cm
cooling area
30
170
50
K/W
K/W
T2
Rthja
Thermal Resistance
Chip/Ambient (TSSOP8)
soldered to PCB,
therm. pad soldered to approx. 2cm
cooling area
30
60
K/W
iC-HK
155MHz LASER SWITCH
Rev D1, Page 5/8
ELECTRICAL CHARACTERISTICS
Operating Conditions: VDD= 3.5..5.5V, Tj= -25..125C unless otherwise stated
Item
Symbol
Parameter
Conditions
Tj
Fig.
Unit
E
C
Min.
Typ.
Max.
Total Device
001
VDD
Permissible Supply Voltage
3.5
5.5
V
002
I(VDD)
Supply Current in VDD
CW operation
0
80
A
003
I(VDD)
Supply Current in VDD
pulsed operation,
f(EN1, EN2)= 150MHz
0
150
mA
004
V(LDK)
Permissible Voltage at LDK
0
5.5
V
005
Vc(CI)hi
Clamp Voltage hi at CI
Vc(CI)= V(CI)- VDD,
I(CI)= 10mA, other pins open
0.4
1.25
V
006
Vc(EN)hi Clamp Voltage hi at EN1, EN2
Vc(EN)= V(EN)- VDD,
I(EN)= 1mA, other pins open
0.4
1.25
V
007
Vc()lo
Clamp Voltage lo at VDD, LDK,
CI, EN1, EN2, AGND1, AGND2
I()= -10mA,
other pins open
-1.25
-0.4
V
008
Ipd()
Pull-Down Current at
CI, EN1, EN2
1
5
A
009
Toff
Overtemperature Shutdown
120
150
C
Laser Control LDK, CI, EN1, EN2
101
Icw(LDK) Permissible CW Current in LDK
(per channel)
150
mA
102
Ipk(LDK) Permissible Pulsed Current in
LDK (per channel)
f > 100kHz, t
hi
/T > 1:10
700
mA
103
I(LDK)rk
Current in LDK in reference to
resistor RK (per channel)
V(CI)= 1.75V, Tj= 27C; ton= 1ms
RKx= 0
S
RKx= 1
S
RKx= 2
S
RKx= 5
S
RKx= 10
S
RKx= 50
S
2
54
47
40
28
20
3.8
80
64
57
41
28
10
115
95
79
56
36
13
mA
mA
mA
mA
mA
mA
104
I(LDK)ci
Current in LDK in reference to
the voltage at CI (per channel)
RKx= 0
S
, Tj= 27C; ton= 1ms
V(CI)= 1.5V
V(CI)= 1.75V
V(CI)= 2V
V(CI)= 3V
V(CI)= 4V
V(CI)= 5V
2-6
28
54
85
275
456
655
45
80
120
340
590
835
70
115
168
410
788
1050
mA
mA
mA
mA
mA
mA
105
tk
I(LDK) Temperature Coefficient
0.5
%/K
106
Vs(LDK)
Saturation Voltage at LDK
I(LDK)= 40mA
I(LDK)= 60mA
I(LDK)= 150mA
1.2
1.3
1.5
V
V
V
107
I0(LDK)
Leakage Current in LDK
ENx= lo, V(LDK)= VDD
0
10
A
108
tr()
LDK Current Rise Time
Iop= 150mA,
I(LDK): 10%
90%Iop
1
1.5
ns
109
tf()
LDK Current Fall Time
Iop(LDK)= 150mA,
I(LDK): 90%
10%Iop
1
1.5
ns
110
tp()
Propagation Delay
V(ENx)
I(LDK)
ENx hi
lo,
V(50%)
I(50%)
1
3
ns
111
Vt(ENx)
Input Threshold Voltage
33
50
77
%VDD
112
V(CI)
Permissible Voltage at CI
0
5.5
V
113
Vt(CI)
Threshold Voltage at CI
I(LDK)< 5mA
0.75
1.15
V
114
CR()
Current Matching
Channel1/Channel2
V(CI)= 0..VDD,
I(LDK)= 30..300mA, RK1= RK2
0.95
1
1.05
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