PCO-6131 FIXED PULSED/CW LASER DIODE DRIVER MODULE * * * * * * * * The PCO-6131 is a compact, OEM-style high power pulsed current source designed to drive diode lasers, bars and arrays in pulsed, QCW or CW modes. It delivers output current variable from 1A to 125A, pulse widths variable from <100ns to DC, and pulse repetition frequencies variable from single-shot to 500KHz at duty cycles up to 100%. The PCO-6131 features a user-adjustable variable rise time control. This innovative feature allows the user to adjust the rise time within a range of <30ns to >2.5s by means of a PCB mounted potentiometer, to optimize the driver's rise time for the user's application. The PCO-6131 is based on a hysteretic, average current, switch-mode regulator. This type of regulator is a variable frequency, variable pulse width design which maintains current in an energy storage inductor between a minimum and maximum level. The ripple is limited to the minimum and maximum current determined by the hysteretic controller. The regulator is started when the TTL "enable" line is taken high and runs as long as the enable is high. The use of the hysteretic regulator provides a large input range and high efficiency. A shunting switch shorts the output of the regulator until output current is needed. The pulse is generated by opening the shunt switch for the length of the input pulse.The pulse rise and fall times are then limited only by the stray/ Economical OEM Module 0A to 125A Output 2.5kW Maximum Average Output Power 20V Maximum Output Voltage User Adjustable Rise Time <100nS to DC Pulse Width Repetition Frequency Single Shot to 500kHz Current Monitor Output (Optional) parasitic capacitance and inductance of the shunting switch and output leads. No power is dissipated in the driver until it is enabled. When enabled, at 125A maximum output approximately 75W is continuously dissipated in the driver to maintain the current in the energy storage inductor (see note #1 on next page for more information). The PCO-6131 requires user-supplied +24VDC support power, a CMOS (+5V) gate signal, and a TTL-level enable/ disable signal. The high current output is derived from the +24VDC DC input. The output pulse width and frequency are controlled by the gate signal. The output current amplitude is controlled by a PCB-mount potentiometer. A current monitor output may be viewed with an oscilloscope, providing a straight-forward means to observe the diode current waveform in realtime. To protect the laser diode and the driver, circuitry is incorporated into the driver that disables the output if the +24VDC support power drops below 18V. Clamp diodes are incorporated into the output network to protect the laser diode against reverse voltage conditions. The rugged, compact design and high power capability of the PCO-6131 make it an excellent OEM choice for driving high power laser diodes. Specifications PARAMETER VALUE PULSE OUTPUT CURRENT Amplitude Range Means Of Adjustment Output Polarity Pulse Rise Time Pulse Width Pulse Recurrence Frequency Range Maximum Duty Cycle Output Pulse Ripple/Droop Jitter Efficiency Output Connector 0A to 125A Trimpot Mounted on PCB or External Analog Voltage Program. Jumper Selectable Positive Variable From <30nS to >2.5uS (10% to 90%) User Adjustable Through Trimpot Mounted on PCB <100nS to DC Single Shot to 500kHz 100% ~2A (<2% at 125A) <3nS First Sigma >75% at 50% Duty Cycle 125A Output * High Current DSUB PCB Mounted DIODE FORWARD VOLTAGE Amplitude 20V Maximum GATE INPUT Type Gate Input Positive Edge Trigger +5V CMOS CURRENT MONITOR OUTPUT Current Monitor (PCA-9155 Optional) Current Monitor Connector 1000A/1V Terminated Into 50 +3% Of The Actual Current BNC CONTROL FUNCTIONS Output Enable/Disable TTL Input High = Enabled GENERAL Input Power +24VDC Unregulated * Operating Temperature 0C to 40C Cooling Air Cooled Dimensions (D X W X H) 6.5" x 8" x 3.3" (16.51cm x 20.3cm x 8.4cm) SPECIFICATIONS SUBJECT TO CHANGE WITHOUT NOTICE *The idle power consumption (power consumed when the driver is enabled but not pulsing) varies non-linearly with output current, and can be approximated by the formula PIDLE=I x 0.023 where I is the output current setpoint. When pulsing, the switching losses (PSW) are about 30W. Therefore the 24VDC power requirements can be approximated by the formula PSW + [IOUTVOUT + IOUT (0.030)]DC + PIDLE (1-DC) where VOUT is the diode forward voltage and DC is the duty cycle. For example, at 40A output current, 10V diode voltage and 30% duty cycle, the power consumption is 30W + [40A x 10V + 40A x 0.03].3 + [40A x 0.023](1-.3) = 190W. The +24VDC support power should be sized to provide this average power.