Low noise laser diode driver with modulation
Koheron DRV200 drivers are ultra-low noise current drivers combining a very stable current bias with a ±1 V modulation input from DC to 5 MHz. Current bias can be set from 0 to 200 mA with a manual potentiometer. A jumper allows to choose between 3 modulation gains.
|Laser current||0 - 40 mA||0 - 200 mA||0 - 400 mA|
|Supply voltage VS||5 V or 6 V||5 V or 6 V||5 V or 6 V|
|Compliance voltage 5V supply||2.8 V at 50 % current max., 1.8 V at current max.||2.8 V at 50 % current max., 1.8 V at current max.||2.8 V at 50 % current max., 1.8 V at current max.|
|Compliance voltage 6V supply||3.8 V at 50 % current max., 2.8 V at current max.||3.8 V at 50 % current max., 2.8 V at current max.||3.8 V at 50 % current max., 2.8 V at current max.|
|3 db modulation bandwidth||8 MHz||6 MHz||6 MHz|
|Current monitor gain||100 mV/mA (up to 40 mA)||20 mV/mA (up to 200 mA)||10 mV/mA (up to 400 mA)|
|Temperature coefficient||30 ppm/°C||30 ppm/°C||30 ppm/°C|
|RMS noise (10 Hz - 1 MHz)||65 nArms||255 nArms||530 nArms|
|Current noise density (1 kHz)||55 pA/√Hz||270 pA/√Hz||480 pA/√Hz|
|Current limit||48 mA (ILIM H), 32 mA (ILIM L)||240 mA (ILIM H), 160 mA (ILIM L)||480 mA (ILIM H), 320 mA (ILIM L)|
|Slow start (90 % setpoint)||1.0 s||1.0 s||1.0 s|
|Modulation gains||200 µA/V, 2 mA/V, 20 mA/V||1 mA/V, 10 mA/V, 100 mA/V||2 mA/V, 20 mA/V, 200 mA/V|
|Outside Dimensions||72 mm x 38 mm x 14 mm||72 mm x 38 mm x 14 mm||72 mm x 38 mm x 14 mm|
|Compatible lasers||Floating diodes||Floating diodes||Floating diodes|
More Laser drivers
The figure below shows the current noise of the different DRV200 laser driver variants operated at a maximum rated current:
Current noise was measured across a 30 Ω resistor for the 40 mA laser current version (A-40) and a 5 Ω resistor for the 200 mA laser current version (A-200) and for the 400 mA laser current version (A-400).
The figure below shows the current evolution of the 200 mA laser current version driver (A-200) delivering 200 mA over 40 hours. The ambient temperature is 25 °C. Current is measured using a 5 Ω precision resistor and a 7.5-digit digital voltmeter.
Fluctuation is about 10 ppm per day.
The figure below shows the current variation for different ambient temperatures between 5 and 55 °C. Temperature coefficient is below 30 ppm/°C.
DC current modulation input
The DC modulation input controls the current setpoint. It combines large bandwidth and high linearity.
Modulation performance are characterized using a DFB laser. Large and small signal correspond to a modulation signal of 2 Vpp and 500 mVpp, respectively. The modulation is detected by a 70 MHz DC coupled PD100 photodetector and measured on an oscilloscope.
- 2 - July 2018: Add jumpers for selection of current limit (High / Low) and supply voltage (5 V / 6 V).