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iC-HG3 A LASER SWITCH
Rev B2, Page 1/20
FEATURES
♦ Six channel laser switch from CW up to 200 MHz
♦ CW operation with up to 500 mA per channel
♦ Pulsed operation with up to 1.5 A per channel
♦ Spike-free switching of the laser current
♦ 6 x 1 channels with TTL inputs
♦ 3 x 2 channels with LVDS inputs
♦ Operates as six independent voltage-controlled current sinks
♦ Outputs (LDKx) are 12 V capable for blue/green laser diodes
♦ Fast and slow switching mode
♦ Simple current control at pins CIx
♦ CIx voltage < 3 V for full CW current
♦ Wide supply voltage range from 3 to 5.5 V
♦ All channels can be paralleled for up to 3 A CW and 9 A pulsed
operation
♦ Multiple iC-HG can be connected in parallel for higher currents
Item Symbol Parameter Conditions UnitNo. Min. Typ. Max.
205 R(ENx) Differential Input Impedance at
ENx
V(ELVDS) > 65% VDD, V(ENx) < VDD − 1.4 V,
LVDS
14 28 kΩ
206 Vdiff Differential Voltage Vdiff = |V(EN1,3,5) − V(EN2,4,6)|;
V(ELVDS) > 65% VDD, LVDS
200 mV
207 V() Input Voltage Range V(ELVDS) > 65% VDD, LVDS 0.6 VDD −1.4
V
Input ELVDS
301 V(ELVDS) Voltage at ELVDS ELVDS open 48 50 52 %VDD
302 Ri(ELVDS) 35 50 70 kΩ
303 Vt(ELVDS) Threshold Voltage TTL Fast to
TTL Slow
16 20 24 %VDD
304 Vt(ELVDS) Threshold Voltage TTL Slow to
Error
36 40 44 %VDD
305 Vt(ELVDS) Threshold Voltage Error to LVDS
Slow
56 60 64 %VDD
306 Vt(ELVDS) Threshold Voltage LVDS Slow to
LVDS Fast
74 80 84 %VDD
307 Vhys() Hysteresis 10 25 50 mV
Ouput NER
401 Vsat(NER) Saturation Voltage at NER ELVDS open, I(NER) = 2 mA 0.6 V
402 I(NER) Current in NER ELVDS open, V(NER) > 0.6 V 3 9 20 mA
Overtemperature
501 Toff Overtemperature Shutdown rising temperature 130 170 °C
502 Ton Overtemperature Release falling temperature 120 160 °C
503 Thys Hysteresis Toff − Ton 5 °C
Power On
601 VON Power On Voltage VDD rising voltage 2.9 V
602 VOFF Power Down Voltage VDD falling voltage 1.5 V
603 Vhys Hysteresis 50 500 mV
iC-HG3 A LASER SWITCH
Rev B2, Page 8/20
CONFIGURATION INPUT ELVDS
Pin ELVDS selects between 6 channel TTL mode or 3
channel LVDS mode and chooses slow or fast switch-
ing speed. The unconnected pin ELVDS is an error
condition signaled at pin NER with the laser current
disabled.
Pin ELVDS connected to GND selects the six channel
fast TTL mode. Pin ELVDS connected to 30% VDD
selects the six channel slow TTL mode. Pin ELVDS
connected to 70% VDD selects the three channel slow
LVDS mode. Pin ELVDS connected to VDD selects the
three channel fast LVDS mode.
An easy way to set the slow operation mode for TTL
and LVDS mode is to connect a voltage divider at pin
ELVDS. Figure 1 shows the recommended voltage di-
vider for slow TTL mode and Figure 2 shows the rec-
ommended voltage divider for slow LVDS mode.
Figure 1: TTL Slow Figure 2: LVDS Slow
DIGITAL INPUTS EN1...6
EN1...6 are the digital switching inputs. With pin
ELVDS set to 6 channel TTL mode, each pin ENx en-
ables the current sink at the respective LDKx. With pin
ELVDS set to 3 channel LVDS mode, the odd ENx pins
are the positive and the even ENx pins are the neg-
ative LVDS inputs. EN1 and EN2 control LDK1 and
LDK2, EN3 and EN4 control LDK3 and LDK4 and EN5
and EN6 control LDK5 and LDK6. For correct LVDS
operation 100 Ω terminating resistors between the re-
spective EPx and ENx pins, very close to the inputs,
are strongly recommended. Input pins from unused
channels have to be connected to GND (TTL opera-
tion) resp. EPx to GND and ENx to VDD (LVDS opera-
tion).
iC-HG3 A LASER SWITCH
Rev B2, Page 9/20
ANALOG CURRENT CONTROL VOLTAGE INPUTS CI1...6
The voltage at pins CI1...6 sets the current in pins
LDK1...6. Figures 3 and 4 show the temperature de-
pendency of the current in a single LDKx output versus
the voltage at CIx for a typical device. Figures 5 and
6 show the min., typ. and max. variations between de-
vices at 27 °C temperature. The voltage at pins LDKx
is 2.5 V.
Figure 3: I(LDKx) vs. V(CIx) at VDD = 5 V Figure 4: I(LDKx) vs. V(CIx) at VDD = 3.3 V
Figure 5: I(LDKx) vs. V(CIx) at VDD = 5 V Figure 6: I(LDKx) vs. V(CIx) at VDD = 3.3 V
iC-HG3 A LASER SWITCH
Rev B2, Page 10/20
LASER OUTPUTS LDK1...6
LDK1...6 are the current outputs for the laser diode
cathode. For high speed operation, connect the laser
diode as close as possible to this pins to minimize the
inductance. To ensure a high switching speed, it is
important to minimise the inductance of the whole cur-
rent loop (cf. Figure 7, marked red) consisting of iC-
HG (pins LDKx and AGNDx), the laser diode (anode
and cathode), the backup capacitors as well as the en-
closed area. It may still be necessary though to use an
R/C snubber network for damping L/C oscillations.
Power &TemperatureMonitor
iC-HG
80%
60%
40%
20%
CVDD110μF
100nFCLDA3
10μFCLDA2
&
&
LD2
LD3
LD4
LD5
LD6
CLDA410nF
CI310nF
10nFCVDD3
&
CLDA1100μF
+
-
RNER
CVDD2100nF
10KCI110nF 10nF
CI210nF
CI6CI510nF10nF
CI4
LD1
CI6
EN6
ELVDS
VDD
..12V
3..5.5V
ENTTL1
ENTTL2
ENTTL3
ENTTL4
ENTTL5
ENTTL6
CI1
CI3
CI5
CI6
CI4
CI2
NERROR
LDK1
AGND1
CI1
EN1
EN2
LDK2
AGND2
CI2
LDK3
AGND3
CI3
EN3
LDK4
AGND4
CI4
EN4
VDD
GND
NER
LDK5
AGND5
CI5
EN5
LDK6
AGND6
&
&
10μFCVDD1
CLDA3100nF
CLDA210μF
&
100μFCLDA1
10nFCLDA4
10nFCI3
CVDD310nF
LD2
LD3
LD4
LD5
LD6
100nFCVDD2
LD1
CI610nF10nF
CI5CI410nF10nF
CI1 CI210nF
RNER10K
Figure 7: Current loop
Depending on the residual inductance in the laser
current path and the actual laser current, fast free-
wheeling diodes from LDKx to VLDA may be required
(cf. Figure 8, diode D1) to protect the outputs. The an-
ode of the free-wheeling diode should be close to the
to be protected LDKx output and the cathode close to
the backup capacitors at VLDA for the free-wheeling
current to be dumped into, when switching the respec-
tive channel off.
Power &TemperatureMonitor
iC-HG
80%
60%
40%
20%
+
-
RNER
CVDD2100nF
D1
10KCI110nF 10nF
CI2
LD5
LD6
CI310nF
CI4
10nFCVDD3
LD2
LD3
LD4
LD1
10nFCI6CI5
10nF10nF
10μFCLDA2
CVDD110μF
100nFCLDA3
&
&
CLDA410nF
&
CLDA1100μF
LDK6
AGND6
CI6
EN6
ELVDS
VDD
3..5.5V
ENTTL1
ENTTL2
ENTTL3
ENTTL4
ENTTL5
ENTTL6
CI1
CI3
CI5
CI6
CI4
CI2
..12V
NERROR
LDK1
AGND1
CI1
EN1
EN2
LDK2
AGND2
CI2
LDK3
AGND3
CI3
EN3
LDK4
AGND4
CI4
EN4
VDD
GND
NER
LDK5
AGND5
CI5
EN5
RNER10K
100nFCVDD2
D1LD1
CI610nF10nF
CI5CI410nF
CVDD310nF
LD2
LD3
LD4
LD5
LD6
10nFCI3
10nFCI1 CI2
10nF
10μFCVDD1
CLDA3100nF
CLDA210μF
&
100μFCLDA1
10nFCLDA4
&
&Figure 8: Free-wheeling diode
PULSED OPERATION
The current for pulsed operation may be higher than
for CW operation. Therefore the RMS current of the
pulse train has to be considered.
Ipulsemax= ICWmax
·
√repetition time(T )
pulse time(t)(1)
With ICWmaxfrom Electrical Characteristics No. 101 and
pulses < 10 µs. So for a single channel operated with
a 50% duty cycle, the max. laser current becomes
Ipulsemax= 500 mA ·
√2 = 707 mA
ANALOG GROUNDS AGND1...6
AGND1...6 are the ground pins for the channels. It is
recommended to connect all AGND1...6 pins to GND.
ERROR OUTPUT NER
The open drain pin NER is a low-active error output.
Signalled errors are ELVDS open or at 50% VDD, VDD
undervoltage and thermal shutdown.
iC-HG3 A LASER SWITCH
Rev B2, Page 11/20
THERMAL SHUTDOWN
iC-HG is protected by an integrated thermal shutdown
feature. When the shutdown temperature is reached
all channels are disabled. Falling temperature after
this shutdown will unconditionally enable all channels
again. Necessary precaution to prevent damage of the
laser may be to also disable any external control cir-
cuits for the laser output power or current control dur-
ing thermal shutdown. The error signal at pin NER can
be used to e.g. disable the control circuit.
APPLICATION EXAMPLES
10μF
AGND5
10nFCI
&
100nF
Power &
&
CI
LDK6
CLDA1
CVDD3CVDD2
10nF
+
100μF
CVDD3
CI6
EN5
AGND6EN6
10K
CVDD2
..12V
ELVDS
CI3
EN3
EN4
40%
100
&EN1
AGND1
EN2
CI
VDD
AGND3
LDK3
60%
AGND2
iC-HGCVDD1
NER
&
CLDA3100nF
LDK4
80%
LDK1
10μF
GND
LDK2
100nF 10nF
CLDA1
10μF
100μF
3..5.5V
20%
CI1
-
10nF
CLDA2
LDK5
AGND4
NERROR
CI4
Monitor
RNER
10nF
CI5
10nF
10K
&
RNER
RLVDS
CLDA3
100nF
&
Temperature
CLDA4CLDA4
CVDD1
RLVDS
EN-LVDS
10μFCLDA2
VDD
100
EN+LVDS
CI2
Figure 9: 1 channel LVDS fast
iC-HG3 A LASER SWITCH
Rev B2, Page 12/20
3.32k
RELVDS2Temperature
10nF
10nF
10μFCVDD2
CLDA2
100
CLDA2
RNER
100nFCLDA4
10μF
10K10K
100nF
NER
Power &
CI
100
CI5
10μF
+
CI6
10nF
10nF
EN1
..12V
EN2
EN5
100μF
&
CLDA1
RLVDS
CVDD1
ELVDS
&
LDK6
EN6
CI4
&
40%
LDK4
CLDA1
AGND4
AGND3
RELVDS2
CI1
CI2
EN+LVDS
CI
80%
EN-LVDS
7.5k
LDK3
VDD
CICI3
LDK1
AGND2
EN4
AGND1
VDD
LDK2
NERROR
GND
EN310nF
&
3..5.5V
LDK5
-
100nF
RNER
Monitor
60%
AGND5
100nF
iC-HG
&
CVDD3CVDD1
RELVDS1RELVDS1
7.5k
100μFCLDA4
CVDD3
10nF
RLVDS
AGND6
10μF
&
CLDA3CLDA3
3.32k
CVDD2
20%
Figure 10: 1 channel LVDS slow
iC-HG3 A LASER SWITCH
Rev B2, Page 13/20
Temperature
VDD
iC-HG
10K
EN6
10nF
40%
10nFCVDD1CVDD1
&
100nF
AGND5
CVDD2
CI5
100μF
RNER
Power &
VDD
10nF
60%
EN1
CI
10K
+
CLDA3
CI2
10nF
10μF
EN3
NERROR
GND
CLDA4
-
CI3
AGND3
CVDD3
CLDA3
..12V
AGND1
20%
CI4
EN2
LDK1
RNER
EN5
&
CI
&
AGND2
AGND4
LDK3
LDK2
CLDA1
LDK4
&
100nF
100μF
ELVDS
NER
3..5.5V
CI1
CVDD2
ENTTL
EN4
100nF10μF
LDK6
CLDA2
10nF
AGND6
CI6
10μF
10nFCLDA4
100nF
Monitor
CLDA1
CVDD3
&
10μF
LDK5
CLDA2
CI
&
80%
Figure 11: 1 channel TTL fast
iC-HG3 A LASER SWITCH
Rev B2, Page 14/20
RELVDS1
Monitor
10nF
100nF
CLDA4
Temperature
10K
10nF
&
LDK6
100nF
10nF
RELVDS2
iC-HGCVDD3
7.5k
10μF
3.32k
ELVDS
3..5.5V
10nF
7.5k
CVDD3
10μF10μF
&
Power &
CVDD2
CLDA3
EN1
CVDD1VDD
RNER
-
&
100nF
EN3
AGND1
10nFCI
100nF
10K
ENTTL
NERROR
CI
CI
LDK4
40%
VDD
..12V
CI4
CI3
&AGND2
CI2
CLDA1
CI6
RNER
CLDA1
3.32k
LDK3
60%
AGND4
AGND3
LDK1
80%
NER
LDK2
RELVDS2
CI1
AGND6
EN2
GND
CLDA4
EN4
10nF
CLDA2 CLDA3
LDK5
&
100μF
CVDD2
&
100μF
+
AGND5
EN6
CLDA2
20%
CVDD1
RELVDS1
10μF
CI5
EN5
Figure 12: 1 channel TTL slow
iC-HG3 A LASER SWITCH
Rev B2, Page 15/20
GND
CI3
iC-HG
&10nF
CLDA4
LD3
10nF
Monitor
Power &
RLVDS3
100nF
CVDD2
+
10μF
100
10nF
100nF
CI3
CVDD2CVDD1
10μFCLDA2
100
RLVDS2
AGND1
AGND3
LDK5
CI2
10nF
CI1
&
100
LDK1
-
AGND6
EN+LVDS2
LD2
EN-LVDS2
3..5.5V
EN1
CI1
..12V
LD1
VDD
LDK2
VDD
10nF10μF
40%
CVDD3
LDK6
CLDA4
NERROR
10KRNER
NER
EN6
10K
CI2
EN3
100nF
CI3
EN+LVDS3
LDK3
ELVDS
EN+LVDS1
AGND5
100
RLVDS3
CI3
EN4
EN-LVDS3
EN2
&
AGND4
EN-LVDS1
LDK4
&
10nF
10μF
AGND2
CLDA1
EN5
CI5
CI6
RLVDS1
CVDD1
CI4
100μF 10nF
LD1
10nF
RLVDS2
10nF
CI2
LD2
LD3
CLDA1100nF
20%
CI2
80%
RNER
Temperature
CLDA3CLDA3CLDA2100μF
&
100
10nF
100
CI1
60%
CVDD3
&
RLVDS1
CI1
Figure 13: 3 channel LVDS fast
iC-HG3 A LASER SWITCH
Rev B2, Page 16/20
LD5
CI1
CI1
CI6
Tem
pera
ture
10nF
100μ
F
CI4
CVD
D3
CLD
A4
10nF
10nF
-
CI5
CI2
&
CLD
A4
CVD
D1
CLD
A2
100n
F
CLD
A1
10nF
LD6
10μF
10μF
10nF
CI3
CI3
&
100n
FC
LDA3
10nF
10nF
GNDC
LDA1
CI5
CI2
LD6
LDK3
NER
LD2
AGND
5
CI4
AGND
1
CLD
A2
EN6
CI5
EN1
CI4
ENTT
L3
..12V
10μF
LD5
+
AGND
3LD
4
&
10nF
ENTT
L5
&
10nF
LD2
LDK1
CI3
10μF
AGND
6
40%
10nF
ENTT
L1
ENTT
L4
RNE
R
20%
VDD
LDK6
NER
RO
R
AGND
2
Mon
itor
10nF
RNE
R
CVD
D3
10K
ENTT
L6
LDK2
CI4
CI6
VD
D
AGND
4
CI2
EN4
100n
F
3..5
.5V
iC-H
G
LD3
LD1
10nF
CI1
EN2
EN5
LDK5
LDK4
ENTT
L2
EN3
ELVD
S
CI1
LD3
&
60%
CVD
D2
CI2
CVD
D1
10nF
100n
F10
nF
Pow
er &
10K
CI6
&
100μ
F
80%
LD1
10nF
CVD
D2
LD4
CI6
CLD
A3 10nF
CI3
CI5
Figure 14: 6 channel TTL fast
iC-HG3 A LASER SWITCH
Rev B2, Page 17/20
EVALUATION BOARD
iC-HG comes with an evaluation board for test purpose. Figures 15 and 16 show both the schematic and the
component side of the evaluation board.
Figure 15: Schematic of the evaluation board
iC-HG3 A LASER SWITCH
Rev B2, Page 18/20
Figure 16: Evaluation board (component side)
Figure 17: Evaluation board (solder side) with mounting option for heat sink
iC-HG3 A LASER SWITCH
Rev B2, Page 19/20
iC-Haus expressly reserves the right to change its products and/or specifications. An info letter gives details as to any amendments and additions made to therelevant current specifications on our internet website www.ichaus.de/infoletter; this letter is generated automatically and shall be sent to registered users byemail.Copying – even as an excerpt – is only permitted with iC-Haus’ approval in writing and precise reference to source.iC-Haus does not warrant the accuracy, completeness or timeliness of the specification and does not assume liability for any errors or omissions in thesematerials.The data specified is intended solely for the purpose of product description. No representations or warranties, either express or implied, of merchantability, fitnessfor a particular purpose or of any other nature are made hereunder with respect to information/specification or the products to which information refers and noguarantee with respect to compliance to the intended use is given. In particular, this also applies to the stated possible applications or areas of applications ofthe product.iC-Haus conveys no patent, copyright, mask work right or other trade mark right to this product. iC-Haus assumes no liability for any patent and/or other trademark rights of a third party resulting from processing or handling of the product and/or any other use of the product.