TSET: Temperature setpoint monitoring pin.
V
TSET
= V
TREF
+ (1 / 10) * V
TMOD
where V
TREF
is the voltage generated by the TEMP trimming potentiometer. The voltage V
TREF
can be tuned
between 0 and 4 V and can be measured at test point TP2. V
TMOD
is the voltage applied at the TMOD pin. The
PID controller tries to make the voltage V
TACT
equal to the setpoint V
TSET
. The pin output impedance is 1 k
Ω
.
ITEC: TEC current monitoring pin. The TEC current I
TEC
is given by
I
TEC
= 1 A/V * (V
ITEC
- 2.5 V)
where V
ITEC
is the voltage measured at the ITEC pin. The pin output impedance is 1 k
Ω
.
TMOD: Temperature modulation pin. Apply a voltage between -3 V and +3V at this pin to control the
temperature setpoint externally (see description of the TSET pin).
ILAS: Laser current monitoring pin. The laser current I
LAS
is given by
I
LAS
= G * V
ILAS
, where V
ILAS
is the voltage measured at the ILAS pin and G is 50 mA/V for the 200 mA version,
100 mA/V for the 400 mA version and 200 mA/V for the 600 and 800 mA versions. The pin output impedance is
1 k
Ω
.
EN: Laser Enable pin. Apply a voltage between 2.2 V and 4.5 V to enable the laser current.
PD: Output of the transimpedance amplifier that monitors the laser power. This output has 3.9 V/mA gain, a
bandwidth from DC to 20 MHz, and is terminated with a 50
Ω
resistor. The actual laser power depends on the
photodiode integrated in the laser and should be calibrated by the user. The LASER LED brightness is
proportionnal to V
PD
.
Modulation inputs
The CTL101 has two current modulation inputs available on SMA connectors:
DC modulation input for modulation between DC and 10 MHz. Modulation range is ±1 V. A jumper allows to
choose between 3 modulation gains (2 mA/V, 20 mA/V or 200 mA/V for the 400 mA version).
AC modulation input for modulation above 1 MHz. Modulation gain is 20 mA/V.
3 / 3
CTL101
www.koheron.com
