Maiman Electronics LLC
SF8300
10
16.
Analogue control description
16.1.
Laser Driver Enable / TEC Enable
The "Enable" contacts are logic inputs.
Apply high level to
«TEC Enable»
pin to start temperature stabilization. Apply low level to
«TEC Enable»
pin to stop temperature stabilization.
Apply high level to
«Laser Driver Enable»
pin to initiate soft-start sequence of laser diode
driver. Apply low level to
«Laser Driver Enable»
pin to stop the driver.
The enable features are duplicated with on-off switches located on the board (7 in Fig. 7).
16.2.
TEC Error
The «TEC Error» contact is logic output.
TEC error signal generates in overcurrent, short-circuit or circuitry overheat condition.
If an error occurs «TEC Error» pin becomes high.
A TEC error stops the laser driver. To reset the error, restart the device.
16.3.
Laser Driver Overcurrent
The
«Laser Driver Overcurrent»
contact is logic output.
The
«Laser Driver Overcurrent»
pin is intended for monitoring the status of the protection
circuits. When the current protection is activated, the laser driver stops, the output terminals are
shunted, the LED on the board lights up red. The high logic level in the contact indicates the
presence of shunting of the output terminals. The current generator cannot be restarted after the
protection has tripped. To reset the protection, restart the driver.
16.4.
Reference voltage 2.5V
The
«+2.5V»
pin is intended for supplying a reference voltage to external potentiometers
etc.
,
which may be used for current and temperature setting.
16.5.
Laser Current Set
The
«Laser Current Set»
pin is an analog input.
The
«Laser Current Set»
is intended for setting the driver output current amplitude. Apply
voltage to the
«Laser Current Set»
with respect to GND to control the output current. Signal
resolution depends on driver model, maximum amplitude of the signal is 2.5V.
The
«Laser Current Set»
pin can be used for analogue modulation by applying sign, square or
ramp signal with the DC component. Please, control the output current while using this feature. In
this case, the value of the DC component determines the average current in the load, and the
amplitude of the signal determines the modulation amplitude. It is necessary to ensure that the
current for analog modulation does not exceed the current protection threshold. Analogue
modulation amplitude depends on frequency.
ATTENTION!
If you use arbitrary/function generator or lab PS for current set, make sure it is in High Z
mode, please, control the current set and current monitor pin voltages while getting started. When you
using a generator with an output "50 Ohms", the value on the screen of the device can be less than the
actually set 2 times. Be careful, monitor the voltage on the contact
«Laser Current Set»
with an
oscilloscope.