RedWave Labs C158 User manual

Operating manual
Laser Controller
C158

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Laser Controller C158
Contents
Introduction ................................................................................................................................3
Absolute Maximum Ratings..........................................................................................................4
Mechanical Information................................................................................................................4
Electrical Characteristics...............................................................................................................5
Power Connector J6.....................................................................................................................7
Laser TEC Connector J7...............................................................................................................7
Laser Connector J8......................................................................................................................8
Control and Monitor Connector J4.................................................................................................8
Control and Monitor Connector J5 (SMB).......................................................................................9
Test Connector J1........................................................................................................................9
DIP SwitchS1........................................................................................................................... 10
Status LED............................................................................................................................... 10
Temperature Set Point .............................................................................................................. 11
Temperature Measurements ...................................................................................................... 11
PI Control ................................................................................................................................ 12
Integral heat sink...................................................................................................................... 12
Power dissipation ..................................................................................................................... 12
External connections and cables................................................................................................. 12
Installation ............................................................................................................................... 13
Certification.............................................................................................................................. 13
Warranty and returns ................................................................................................................ 13
Return procedure...................................................................................................................... 13
Revisions ................................................................................................................................. 13

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Laser Controller C158
Introduction
Redwave Labs Laser Controller C158 comes with integrated temperature driver and
laser driver in one package. Temperature control is fully linear and has capability to
use separate power supply for laser TEC. TEC control can be done via built-in PI
loop or external signal. Laser driver has analog bandwidth of 250 kHz and separate
fast TTL compatible switching provided via SMB connector. Laser current has a
hardware limit of 250 mA which cannot be exceeded in any case.
Features
Laser Controller C158 provides full control for semiconductor laser including laser diode
control and integrated temperature control.
Applications
Spectroscopy, Laser, Precision Instrument, OEM applications
Specifications
Parameter
Value
Power
Dual
Option 1: +12 V, 2 A or +12 V/0.5A
Option 2: +5V/1.5A; -12 V, 0.5 A
Laser Current Control
Laser current
0 - 250 mA. Hardware limit. Can be modified for
customized versions
Compliance voltage
> 4.0 V
Setting accuracy
2 % fs
Noise (RMS)
< 2µA
Drift
< 20 µA
Temperature coefficient
50 ppm/C
Current limit
250 mA
Setting accuracy of current limit
2 % fs
Laser External Control
Voltage range
0 to 10 V
Input impedance
10 kOhm
Modulation coefficient ( I const )
20 mA/V
3dB Bandwidth
DC … 250 kHz
TTL modulation, rise / fall-time
250 ns
Interlock
Yes
TEC control
TEC current
0 … +- 1.0 A /1.5A
TEC voltage
> 8.0 V
Max output power
12 W
Current limit
1A or 1.5 A
Input sensor
Thermistor 10 kOhm or 100 kOhm at 25 C
PID control
Internal PI control or External direct TEC current
control
Connectors
Laser
Integrated Azimuth Electronics 14 pin connector
with heat sink. NEL DFB laser pinout. Can be
replaced with optional DB15 connector.
Power
Molex MicroFit 8 pin.
Control
Molex MicroFit 12 pin.
Dimensions (WxHxD)
120 x 92 x 30 mm
Weight
350 g
Storage Temp
-55 to 100 C
Operating Temp
-40 to 85 C
RedWave Labs Ltd keeps improving its products and therefore some specifications can vary.

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Laser Controller C158
Absolute Maximum Ratings
Symbol
Parameter
Ratings
Unit
Vdd1
Supply positive voltage / Laser driver and TEC
+12±10%
Volt
Vdd2
Supply positive voltage / Separate TEC rail
+5;+10%;-0%
Volt
Vee
Supply negative voltage / Laser driver and
TEC
-12±10%
Volt
Top
Operational Temperature
-40 to 85
Deg C
Tst
Storage Temperature
-55 to 100
Deg C
Mechanical Information
Parameter
Value
Unit
Length
4.75 (120.65)
Inch (mm)
Width
3.65 (92.7)
Inch (mm)
Height
1.01 (25.1)
Inch (mm)
Weight
350
gram

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Laser Controller C158
Electrical Characteristics
Parameter
Comments
Value
Unit
POWER
Supply positive voltage
Vdd1 / Laser driver and
TEC
Positive supply voltage for laser driver, all
control circuits and TEC. 2 A minimum is
required for single positive power supply
12 ± 10%
V
Supply positive voltage
Vdd2 / Separate TEC
Power
Positive supply voltage for TEC only.
2 A minimum capabilities is required.
Designed to use 5 V rail to minimize
overall power consumption and heat
dissipation
5 V; +10%;-
0%
V
Negative supply voltage
Vee
Negative supply voltage for laser driver, all
control circuits and TEC
-12 ± 10 %
V
LASER DIODE CONTROL AND MONITOR
Laser current Ild limit
Hardware laser limit. Can be modified for
customized versions
250
mA
Laser Compliance
voltage Vcomp
Minimum voltage across laser diode. Can
be change for customized versions.
4
V
Noise (RMS)
Integrated noise (DC-250kHz)
2
µA
Laser current drift
Laser current drift at constant temperature
20
µA
Laser current
temperature coefficient
Temperature drift of the reference
50
Ppm / deg C
Laser current range
Laser current maximum current
250 ( for
custom version
can be less;
mentioned in
the part
number C154-
70 –70 mA,
for example)
mA
Laser current setting
accuracy
Set by components tolerance
2
% of full
scale
Laser current set voltage
External transfer function ranges
0-10 (for
custom version
less than 10V
depending on
the version)
V
Laser current set voltage
impedance
10
kOhm
Laser current
modulation coefficient
Transfer function for laser current
modulation
20
mA/V
Laser current
modulation bandwidth
-3 dB
250
kHz

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Laser Controller C158
Parameter
Comments
Value
Unit
Laser current TTL
modulation rise/fall time
Additional modulation capabilities on top
of the analog modulation. Fast ON/OFF
switches
250
nS
Laser current monitor
Monitor averaged laser current
0-10 (for
custom version
less than 10V
depending on
the version)
V
Laser current interlock
Available laser interlock. Can be
overridden with DIP-switch
TEC CONTROL AND MONITOR
TEC control type
Linear bipolar
TEC current range
Maximum range can be change with DIP
switch S1
0…±1;
0…±1.4
Amp
TEC power supply
TEC power supply can be selected from
+12V and +5V. +5V allow to improve
power efficiency for TEC with 1 Ohm and
maximum current of 1.5 A.
+5 ; +12
V
TEC compliance voltage
Voltage across TEC element
Vdd-3
V
Maximum TEC power
Maximum power for 12 V power supply
12
W
TEC current limit
Selected with DIP switch S1
1 of 1.4
Amp
Input sensor
TEC input sensor. Selected with S1 DIP
switch. Configured in bridge mode.
100 or 10
kOhm
PI control
PI analog control loop (internal mode) or
external loop though J2 connector (pin
3).Selected with S1 DIP-switch.
External or
Internal
TEC current external
transfer function
Direct control of TEC. Input range –10
to+10 V
200
mA/V
TEC current monitor
Independent TEC current monitor at pin 4
of J4 connector
5.0
V/A
TEC disable
TEC current disable function: DIP-Switch
S1.
CONNECTORS
Power J6
Molex 8 pin Micro Fit connector p/n
43045-0800
Control and monitors J4
Molex 12 pin Micro Fit connector p/n
43045-1200

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Laser Controller C158
Parameter
Comments
Value
Unit
Laser connector
Integrated Azimuth Electronics 14 pin
connector with heat sink. NEL DFB laser
pinout. Can be replaced with optional
DB15 connector.
Test connector J1
Test connector: can be used for remote
control of the driver. Molex p/n 87831-
1620
Power Connector J6
PIN#
Abbreviation
Name
Description
1
Vdd1
Positive power
+12 V
Electrically connected to Pin 5.
2
GND Main
Ground for Vdd1
Ground for the +12/-12 power supplies
3
Vdd2
TEC Power
Positive power for separate TEC power: +5 V. Electrically
connected to pin 7
4
Vee
Negative power –
12 V
Electrically connected to Pin 8.
5
Vdd1
Positive power
+12 V
Electrically connected to Pin 1.
6
GND TEC
Ground for Vdd2
Ground for the +5 power supply. Connected to GND Main
with 1 Ohm resistor at connector.
7
Vdd2
TEC Power
Positive power for separate TEC power: +5 V. Electrically
connected to pin 3
8
Vee
Negaive power –
12 V
Electrically connected to Pin 4.
Power connector J6 (pin assignment is on left) is Molex Micro-Fit p/n 43045-0800. Mating
connector is Molex Micro-Fit p/n 43025-0800 with crimp pins Molex p/n 43030-0009. Mating
connector and necessary number of crimp pins are included with C151 Laser controller. Molex
suggested crimping tool p/n 63819-0000 which can be purchased from Digikey Inc
(www.digikey.com)
Laser TEC Connector J7
PIN#
Abbreviation
Name
Description
1
TEC+
Laser package TEC
Positive connection
Connected to J1-15
2
TH+
Laser package
Thermistor Positive
connection
Connected to J1-12
3
TEC-
Laser package TEC
Negative
connection
Connected to J1-16
4
TH-
Laser package
Thermistor Positive
connection
Connected to J1-11

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Laser Controller C158
Power connector J7 (pin assignment is on left) is Molex Micro-Fit p/n 43045-0400. Mating
connector is Molex Micro-Fit p/n 43025-0400 with crimp pins Molex p/n 43030-0009. Mating
connector and necessary number of crimp pins are included with C158 Laser controller. Molex
suggested crimping tool p/n 63819-0000 which can be purchased from Digikey Inc
(www.digikey.com)
Laser Connector J8
PIN#
Abbreviation
Name
Description
1
LD+
Laser Diode Positive Connection
Directly connected to the J1 -1
2
LD+
Laser Diode Positive Connection
Directly connected to the J1 -1
3
GND
Ground
4
PD+
Positive Photodiode
5
LD-
Laser Diode Negative
Connection
Directly connected to the J1 -2
6
reserved
7
GND
Ground
8
PD-
Negative Photodiode
Power connector J6 (pin assignment is on left) is Molex Micro-Fit p/n 43045-0800. Mating
connector is Molex Micro-Fit p/n 43025-0800 with crimp pins Molex p/n 43030-0009. Mating
connector and necessary number of crimp pins are included with C158 Laser controller. Molex
suggested crimping tool p/n 63819-0000 which can be purchased from Digikey Inc
(www.digikey.com)
Control and Monitor Connector J4
PIN#
Abbreviation
Name
Description
1
LD_I_CTRL
Laser current Control
Control laser diode current with transfer function of 20
mA/V
2
LD_ON_OFF
TTL control of laser
current
Switches laser current ON/OFF with TTL level (5V) external
signal. Electrically connected to J5 (SMB). 0V-LD_ON; 5V
–LD_OFF.
3
TEC_I_CTRL_EXT
External control of
TEC current
Controls TEC current directly with transfer function of 200
mA/V. Switch S1-3 must be in EXT position. Bandwidth of
TEC control is limited to approximately 50 Hz.
4
TEC_I_MON
TEC current monitor
Shows current of the laser TEC with transfer function
Vmon=Itec * 5.0 V/A.
5
GND
Ground
Control and Monitor Ground connection. Must not be used
for power ground.
6
INTERLOCK-
Negative Interlock
Negative interlock connection. Connected to Ground
directly
7
T_SET_EXTERNAL
External temperature
set point
External temperature set point can be selected with switch
S1-4. Transfer function can be calculated as Rset =
(Vo+0.3119*Vset)/(Vo-0.3119*Vset) * R0; R0=10K or
100K , Vo=5.000V and
1/Tset = A + B * ln(Rset) + C * (ln(Rset))3. Typical values:
A= 1.1280e-03; B=2.3450e-04;C=8.73e-08.
8
LD_I_MON
Laser diode monitor
Monitor average laser diode current with transfer function
50 V/A and bandwidth of approximately 25 kHz.

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Laser Controller C158
PIN#
Abbreviation
Name
Description
9
LIMIT_I_FAULT
TEC current limit
error
0V –normal operation; +5V if current limit (any side) is
reached.
10
GND
Ground
Control and Monitor Ground connection. Must not be used
for power ground.
11
T_ACTUAL_MON
Actual temperature
monitor
Buffered output of the voltage across the thermistor.
12
INTERLOCK+
Positive Interlock
Positive interlock connection. Can be overridden with S1-
6.
Control and monitor connector J4 (pin assignment is on left) is Molex Micro-Fit p/n
43045-1200. Mating connector is Molex Micro-Fit p/n 43025-1200 with crimp pins
Molex p/n 43030-0009 . Mating connector and necessary number of crimp pins are
included with C151 Laser controller. Molex suggested crimping tool p/n 63819-0000
which can be purchased from Digikey Inc (www.digikey.com)
Control and Monitor Connector J5 (SMB)
PIN#
Abbreviation
Name
Description
1
LD_ON_OFF
TTL control of laser
current
Switches laser current ON/OFF with TTL (5V) level external
signal. Electrically connected to J4 Pin 2. 0V-LD_ON; 5V –
LD_OFF.
Laser On/Off connector J5 is standard SMB connector for easy direct connection of laser current fast ON/OFF signal.
Test Connector J1
PIN#
Abbreviation
Name
Description
1
LD+
Laser Diode Positive
Connection
Directly connected to the Azimuth
connector J2 Pins 11 and 13
2
LD-
Laser Diode Positive
Connection
Directly connected to the Azimuth
connector J2 Pin 12
3
RESERVED
4
RESERVED
5
TEC_DISABLE
Laser TEC remote disable
Remote control of Switch S1-1: 0V –
TEC Enable; 5V –TEC disable. Remote
control overrides S1.
6
THERMISTOR_TYPE_CONTROL
10K/100K remote
thermistor selection
Remote control of Switch S1-2: 0V –
100K; 5V –10K. Remote control
overrides S1.
7
PID_CONTROL
Remote PID control
Remote control of PID loop (S1-3): 0V
–External; 5V –Internal (Analog PI
loop). Remote control overrides S1.
8
T_SET_CONTROL
Remote control of set
temperature
Remote control of S1-4: 0V –Internal;
5V –External. Remote control
overrides S1.
9
TEC_I_LIMIT_CONTROL
Remote control of TEC
current limit
Remote control of S1-5: 0V –1A; 5V –
1.4A. Remote control overrides S1.

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Laser Controller C158
PIN#
Abbreviation
Name
Description
10
INTERLOCK_CONTROL
Remote control of Interlock
function
Remote control of S1-6: 0V –Enable;
5V –Disable (Overridden). Remote
control overrides S1.
11
TH-
Laser package Thermistor
Negative connection
Directly connected to the Azimuth
connector J2 Pin 2
12
TH+
Laser package Thermistor
Positive connection
Directly connected to the Azimuth
connector J2 Pin 1
13
RESERVED
14
RESERVED
15
TEC+
TEC_POWER_CONTROL
Directly connected to the Azimuth
connector J2 Pin 6
16
TEC-
Laser package TEC
Negative connection
Directly connected to the Azimuth
connector J2 Pin 7
Test connector J1 (pin assignment is on left) is Molex Milli-Grid p/n 87831-1620. Mating
connector is Molex Milli-Grid p/n 87568-1694 for ribbon cable. C158 comes without
Milli-Grid mating connector. Customized connector arrangement can be used for the
remote control of the switch S1. RedWave Labs can advised on the specific applications
when required.
DIP SwitchS1
S1 can be remotely controlled through J1 except for the TEC power selection (POSITION 8 in table below). This remote
control functionality can be used for integration inside spectrometers or other instruments.
PIN#
Abbreviation
Name
Description
1
TEC_DISABLE
Laser TEC
disable
0V (0) –TEC Enable; 5V (1) –TEC disable.
2
THERMISTOR_TYPE_CONTROL
10K/100K
thermistor
selection
0V (0) –100K; 5V (1) –10K
3
PID_CONTROL
PID control
0V (0) –External; 5V (1) –Internal (Analog PI
loop).
4
T_SET_CONTROL
Control of set
temperature
0V (0)–Internal; 5V (1) –External
5
TEC_I_LIMIT_CONTROL
Control of TEC
current limit
0V (0)–1A; 5V (1) –1.4A
6
INTERLOCK_CONTROL
Control of
Interlock function
0V (0) –Enable; 5V (1) –Disable (Overridden)
7
RESERVED
8
TEC_POWER_CONTROL
Control of TEC
Power
0V (0) –5 V Power supply; 5V (1) –12 V Power
Supply
Status LED
Status LEDs are used for fast visual assessment of the C158 status. LEDs are located close to test connector J1. Default
LED color is red; this can varied in customized versions.
LED #
Abbreviation
Name
Description
1 (Top)
+12 V (Top)
Vdd1
Supply positive voltage Vdd1 / Laser driver and TEC is ON.

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Laser Controller C158
2
+ 5 V
Vdd2
Supply positive voltage Vdd2 / Separate TEC Power is ON
3
- 12 V
Vee
Negative supply voltage Vee is ON
4
TEC I LIM
TEC Current Limit
reached
ON: TEC current limit reached. IF LED 4 is ON longer than 10
seconds then laser temperature might be too high or too low to
achieve adequate stabilization
5
(Bottom)
INLK OFF
(Bottom)
Laser interlock OFF
ON: Laser Interlock is overridden and will not switch the laser off
when activated.
Temperature Set Point
C158 has 2 options to control temperature set point. These options are:i) internal set point with the 11-turn potentiometer
located on the opposite side of laser connector ; ii) external voltage applied to the Pin 7 of the J4 connector.
Type
Selection
Position
Description
Internal (11-turn
potentiometer)
S1
4 (0)
Internal set point: 0.9 to 4.2V set by 11 turn
potentiometer located on the edge opposite to the laser
connector. Voltage is increased in clockwise direction.
With 10K thermistor this range cover from -5C to
+60C.
External
S1
4 –(1)
External set point:-10V to +10V applied to Pin7 of J4
connector. Transfer function can be calculated as Rset
= (Vo+0.3119*Vset)/(Vo-0.3119*Vset) * R0; R0=10K
or 100K , Vo=5.000V and
1/Tset = A + B * ln(Rset) + C * (ln(Rset))3. Typical
values: A= 1.1280e-03; B=2.3450e-04;C=8.73e-
08. Application of the Vset values outside –10 to
+10 V could result in board damage.
Temperature Measurements
Laser Controller C158 has two modes of temperature measurements. Temperature can be measured using the 10K or 100K
thermistor. Selection between modes is made through switch S1-2. C158 uses a high stability voltage reference (V0= 5.00 V)
on the board and measures the voltage across the thermistor using a bridge scheme. Thermistor voltage can be monitored between
pins 11 and 12 of J1.
Temperature can be derived from the voltage across the thermistor using the following formula:
1/T = A + B * ln(Rt) + C * (ln(Rt))3
Rt= Vt/ (V0–Vt) * R0
Where R0= 10.0kOhm for the 10K thermistor and R0=100K for the 100K thermistor. Vtis the voltage across the thermistor.
The 10 µA value of constants A, B and C (A= 1.1280e-03; B=2.3450e-04;C=8.73e-08) should be used to calculate the
correct temperature. For example Vt=2.500 V for T=25 C using 10K thermistor settings and using the 10K thermistor as the
temperature measurement element.
Note: This voltage is different from Tset voltage (see above Temperature Set Point).

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Laser Controller C158
PI Control
C158 has 2 options to control the temperature feedback loop: Internal and External. Internal PI control covers the vast majority
of systems and the P and I control potentiometers can be adjusted to obtain the optimal PI. External PI control can be used if
the user has a digital PID implementation elsewhere and connected to the Pin 3 of J4. Selection between internal and external
control modes is done via S1-3.
Control
Selection
Position
Description
Internal
Proportional
S1
3 –(1)
Internal Proportional Gain setting 2-100 A/V with ¾ turn
linear potentiometer. Gain is increased in CW direction.
Shipped with Proportional Gain=100 A/V.
Internal Integral
S1
3 –(1)
Internal Integral Gain setting 0.55-5 A/(*sec)V with ¾ turn
linear potentiometer. Gain is increased in CW direction.
Shipped with Integral Gain=5.0 A/(V*sec)
External
S1
3 –(0)
External control of TEC/heater current through Pin 4 of the
J4. Transfer function 200 mA/V. Maximum current is
limited by the current limit setting (1.0A or 1.5A).
Proportional and Integral gains can be measured using 3 test points (Common ‘C’, Proportional ‘P’, and Integral ‘I’) just under of
P and I potentiometers. The Proportional gain (A/V) can be calculated using the value of the resistance between ‘C’ and ‘P’ test
points and expressed in kOhm:
m
m
prop R
R
G+
−
=98.14 2400
where Rmis the measured resistance.
The Integral gain (A/(V*sec)) can be calculated using the same approach:
m
in R
G+
+= 15.4
5.0
Integral heat sink
C151 has two options for the laser integrated heat sink (‘Low’ and ‘High’).
‘Low’ heatsink is level with Printed circuit Board (PCB) and allows mount of customers’ designed laser package enclosure. This
option is used when an additional thermal isolation for DFB butterfly package is required.
‘High’ heatsink is about 2.5 mm higher than PCB and typically used for direct mounting of butterfly packages. 2.5 mm elevation
provides minimum stress for package pins.
‘Low’ and ‘High’ option are easy interchangeable and relevant heat sinks can purchased independently.
Power dissipation
C151 laser controllers have been designed to 25 Watt power dissipation without heat sink at normal atmospheric conditions. 25
W dissipated heat is the maximum dissipated power. Most common regime would result in about 15 W heat dissipation. C151
does not require external heatsink.
External connections and cables

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Laser Controller C158
C151 laser controller comes with mating connectors and crimp kit for J4 and J6. Cables for J1, J4 and J6 can be purchased
separately.
Installation
We recommend a first time use of the C151 with a high power load resistor (at least 10W rating) as TEC load and Laser Diode
load. These load should connected to the corresponding pins of J1. Such a set-up will enable a system check before connecting
to the laser temperature controller system and risking potential damages.
Certification
RedWave Labs Ltd certifies that: i) the parts and/or materials were produced in conformance with all contractually
applicable Government and/or Buyer’s specification as referenced in, or furnished with, the above purchase order and ii)
all processes required in the production of these parts and/or materials are listed and were performed by a facility or by personnel
specifically approved or certified by the seller’s cognizant government quality control agency when such approval or certification
is required by an applicable specification. RedWave Labs products are not authorized for use in safety-critical applications (such
as life support) where a failure of the product would reasonably be expected to cause severe personal injury or death, unless
officers of the parties have executed an agreement specifically governing such use of the products.
Warranty and returns
C151 Laser Controllers are warranted against defects in materials and workmanship for a period of 180 days from date
of shipment. During the warranty period RedWave Labs Ltd will replace or repair products which prove to be defective or
damaged. Our warranty shall not apply to defects or damages resulting from: i) misuse of the product or ii) operation
beyond specifications detailed in the current manual.
Return procedure
Customer must obtain a valid RMA number by contacting RedWave Labs prior to the return. In all cases the customer is
responsible for duty fees incurred on all received shipments and on all international returns for both warranty and non-
warranty items; the customer is responsible for any duties, brokers fees or freight charges deemed chargeable to RedWave
Labs Ltd.
Revisions
Revision 1: Original revision