Pockels Cell Driver «HV6-LJ-3.3»
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Pockels Cell Driver «HV6-LJ-3.3»
gnatyuk@mail.ru July 2013
Application

Generation of quasi-rectangular high voltage pulses for the control of electro-optical Q-switches (Pockels cells) in a solid-state laser.
Distinctive Features

✓   Positive high-voltage pulse (Switch-on mode).
✓ Low-voltage DC supply is required (5 ÷ 12 V).
✓ TTL (CMOS) input signal required (3 ÷ 15 V).
✓ Built-in high-voltage source.
✓ Adjustment of a high-voltage pulse either directly on the board (through built-in potentiometer) or remotely.
✓ Monitoring the amplitude of output pulse at a scale of 1:10000.
✓ Possibility of applying external DC-bias voltage source on the Q-switch. 1
✓ Possibility of generate an output pulse in Switch-off mode. 1
✓ «Error-message» (Open Drain) signal if no high-voltage is detected.
✓ LED Indicators: «Power» (green), «Pulse» (yellow), «Error» (red).
Technical Specifications
  • High-voltage amplitude 2
    		•  2000 ÷ 4000 V
  • HV pulse-to-pulse instability
    		•  5 %
  • Max impulse current
    		•  12 A
  • Max load capacitance
    		•  50 pF
  • Rising front duration 3
    		•  3 ÷ 8 ns
  • HV pulse width (factory-set)
    		•  0.6 µs
  • Fall time 3
    		•  3 ÷ 5 µs
  • Max repetition rate (frequency)
    		•
    with 5 VDC 2 kHz
    with 12 VDC 4 kHz
  • HV pulse delay vs. trigger pulse 4
    		•  30 ÷ 50 ns
  • Timing jitter of the HV pulse vs. trigger pulse 4
    		•  < 0.5 ns
  • Input TTL (CMOS) trigger pulse amplitude
    		•  3 ÷ 15 V
  • Input DC supply voltage
    		•  4.5 ÷ 13.5 V
  • Input DC supply current (output high-voltage pulses 3500 V)
    		•
    with 5 VDC and output frequency 1 kHz 380 mA
    with 5 VDC and output frequency 2 kHz 480 mA
    with 12 VDC and output frequency 1 kHz 180 mA
    with 12 VDC and output frequency 4 kHz 320 mA
  • Working temperature range
    		•  –40 ÷ +50 °C
  • Dimensions
    		•  50 × 80 × 20 mm³
  • Mounting holes (∅ 3.3 mm)
    		•  44 × 74 mm
    1 When external HV DC source is used.
    2 Is set from the built-in potentiometer or remotely.
    3 Depends on the load capacitance and input pulse amplitude.
    4 Delay depends on the rising front and trigger pulse amplitude. The higher trigger amplitude, the shorter delay is.
    Layout of main connectors and electronic components
    Input connector J1, type IDC-10M (2.54mm):
    1 – Input trigger pulse
    2 – GND
    3 – Input DC voltage
    4 – GND
    5 – «Error» message signal
    6 – GND
    7 – HV amplitude monitoring 1:10000, or HV amplitude setting: VOUT = 800 × (5 – V7)
    8 – GND
    9 – Reserved (not connected)
    10 – GND

    Output Connector J2, type B3P-VH (3.96mm):
    1 – «negative» Q-switch electrode
    3 – «positive» Q-switch electrode

    Input Connector J3, type B3P-VH (3.96mm):
    1 – GND
    3 – «Plus» DC-bias voltage applied to the Q-switch

    HV amplitude control – RV12.
    TP1 – GND
    TP2 – HV amplitude monitoring 1:10000 (when pin 7 of connector J1 is not connected)

    In order to set HV amplitude remotely using pin 7 of connector J1, it is necessary to move potentiometer RV12 to the position corresponding to the voltage of 3700V. Input resistance (impedance) of pin 7 is 4 kOhm.

    LED Indicators:
    LD1 (green) – «Pwr» – DC voltage detected;
    LD2 (yellow) – «Trig» – input trigger signal;
    LD3 (red) – «Err» – no high-voltage output.
    Electric Block-Diagram
    Switching Waveforms

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