Quad-channel bipolar voltage source
Koheron VREF100 is a quad-channel voltage source that can be adjusted between -5 V and +5 V. It can source or sink up to 40 mA on each channel. Each channel has a coarse and a fine trimmer with a settability of 20 µV. Thanks to its low wideband noise and high stability, the VREF100 can be used to bias sensitive devices such as VCOs or Mach-Zehnder modulators.
|Number of channels||4|
|Output voltage range||±5 V|
|Current driving capability||40 mA (source or sink)|
|Voltage noise density (10 kHz)||1.3 nV/√Hz|
|RMS noise (10 Hz - 1 MHz)||2 µV|
|24 h stability||50 µV|
|Load regulation||35 µV/mA|
|Temperature coefficient||5 ppm/°C|
|Fine ajustment range||±50 mV|
|Outside Dimensions||75 mm x 50 mm x 12 mm|
|Supply voltage||±9 V|
|Operating temperature||0 °C - 40 °C|
The graph below shows the variation of the output voltage of the VREF100 (set to -4 V) when the temperature varies from 0 to 60 °C. Temperature coefficient is about 10 µV/°C.
Voltage stability of the VREF100 has been measured at a temperature of 25 °C and an output voltage of -4 V over 24 hours:
The corresponding Allan deviation is shown below. A minimum Allan deviation of 300 nV is seen between 5 and 100 seconds.
Voltage noise density
The graph below shows the output voltage noise density of the VREF100 when driving a 100 Ω load at different output voltages.
Current driving capability
At 4 V output voltage, the VREF100 sources or sinks up to 60 mA. At -4 V output voltage, it sinks up to 40 mA and sources up to 60 mA.
Application: Voltage Controlled Oscillator (VCO) control
We used the VREF100-50 to control a Minicircuits ROS-2500 Voltage Controlled Oscillator. The VCO is controlled with 4 V, which gives a VCO output frequency of 1.7 GHz.