Name: PCM-7700 Pulsed Current Source
Brand: Berkeley Nucleonics

1Overview

The PCM-7700 series of air-cooled, high-power current sources is designed to drive laser diodes, bars, and arrays with up to 200 A of current at a load voltage of up to 25 V. Both models in the series deliver pulse widths from 500 µs to 50 ms and pulse repetition rates from single shot to 1 kHz.

Two variants cover different duty-cycle needs. The PCM-7700-48 includes a built-in power supply for a complete, self-contained bench unit. The PCM-7700-EX connects to an external supply, which lets the user run higher duty cycles where the application demands them. Directed Energy, Inc. is now a division of Berkeley Nucleonics, and the PCM-7700 ships from the same San Rafael, California build with one support path.

PCM-7700 front view showing controls and output — PCM-7700 pulsed current source. The unit drives low-impedance loads such as diode bars and arrays through a high-current output connector.

2How It Works

The PCM-7700 output current is set with a potentiometer on the included evaluation board or with an analog voltage. Pulse width is controlled by the trigger input, so the host system retains direct control over the shape and cadence of each pulse.

Two control modes are supported. In digital control mode, an input voltage sets the pulse output current and an external trigger signal sets the pulse width. In analog control mode, the output current follows the input voltage directly, which suits arbitrary current profiles driven from an external waveform source. In either mode, the instrument must always be operated within the safe operating area.

For automated test, complete control of the instrument is provided through a DB15 male connector, which carries the trigger, current setpoint, enable lines, and the current and voltage monitors.

PCM-7700 control and evaluation board — The included evaluation board provides potentiometer current setting and access to the DB15 control interface.

PCM-7700 output pulse captured on an oscilloscope — Representative output pulse driving a low-inductance HPL-2400 resistive load.

3Specifications

The PCM-7700 current source meets or exceeds these specifications. All specifications are measured using the standard included output cable and an HPL-2400 low-inductance, high-power resistive load. The load is not included.

Pulse amplitude

Parameter	Specification
Output current range	5 A to 200 A¹
Setpoint resolution	0.050 A
Setpoint accuracy	± 1% of full scale current
Current overshoot	< 0.5% of full scale current
Current rise / fall time	≤ 75 µs (with I_OUT > 10 A)
Pulse width	500 µs to 50 ms
Polarity	Positive
Load voltage (PCM-7700-48)	0 V to 25 V²
Load voltage (PCM-7700-EX)	0 V to 25 V²
Maximum output power	See SOA graphs

Gate

Parameter	Specification
Frequency range	Single shot to 1 kHz
Input voltage levels	0 V: output OFF; 5 V: output ON
Gate pulse width	500 µs to 50 ms (digital control mode); 0 to ∞ ms (analog control mode)
Termination impedance	50 Ω
Connector	DB-15 pin 8

Current setpoint

Parameter	Specification
Input voltage levels	0 V to 10 V (0.000 V = 0 A output; 10.000 V = 200 A output)
Termination impedance	10 kΩ
Response time on change	≤ 5 µs
Connector	DB-15 pin 6

Enable signals

Parameter	Specification
Input voltage levels	0 V: enable; 5 V or open: disable
Termination impedance	10 kΩ
Response time on change	≤ 200 ms
Connector	DB-15 pin 4 (EXT ENABLE 1); DB-15 pin 3 (EXT ENABLE 2)

Monitors

Parameter	Specification
Current monitor	5 mV/A (200 A output = 1.000 V typical)
Current monitor termination	50 Ω
Current monitor connector	DB-15 pin 2
Voltage monitor	60 mV/V (30 V output = 1.800 V typical)
Voltage monitor termination	1 MΩ
Voltage monitor connector	DB-15 pin 1

Output connector

Parameter	Specification
Output connector	2 x Amp 1-770974-0 (pins 1 through 8 = Out−; pins 9 through 16 = Out+)

Power and general

Parameter	Specification
Voltage requirements	100 VAC to 240 VAC
Line frequency	50 Hz to 60 Hz
Power requirements	PCM-7700-48: 1200 W; PCM-7700-EX: 250 W
Connector type	IEC 320-C14
Size (H x W x D)	27 cm x 27 cm x 39 cm
Weight	15 kg
Operating temperature	15 °C to 35 °C
Cooling	Air cooled (air flow from rear to front)

Note 1. Rise and fall time specifications are valid from 10 A to 200 A. Note 2. Operation outside the listed load voltage and maximum power limits can cause permanent damage to the instrument and/or load. See the SOA graphs in the manual for more information. Specifications subject to change without notice. A load board and evaluation board are included.

4Output Protection & Safety

The PCM-7700 must be operated within its safe operating area at all times. The SOA defines the allowed combination of current, pulse width, and repetition rate that keeps the source and the connected diode within thermal and electrical limits. Separate SOA graphs apply to the PCM-7700-48 and the PCM-7700-EX, since the two variants differ in available duty cycle.

Important. Do not operate the instrument outside of the safe operating area. Although the external triggering system allows operation outside the SOA, such operation will result in permanent damage to the PCM-7700, the laser diode, or both. The safe operating area is the region below the line of each SOA graph. Operate only within that region.

The dual enable lines give the host system a positive way to inhibit the output. Use the current and voltage monitors during setup to confirm the operating point before committing a sensitive diode load.

5Control & Interfaces

All control runs through a single DB15 male connector, which suits both bench operation from the evaluation board and integration into an automated test system.

Function	DB-15 pin
Voltage monitor	Pin 1
Current monitor	Pin 2
EXT ENABLE 2	Pin 3
EXT ENABLE 1	Pin 4
Current setpoint	Pin 6
Gate / trigger	Pin 8

Digital and analog control modes are both supported. In digital mode an input voltage sets the current and the trigger sets the width. In analog mode the output current tracks the input voltage, which allows arbitrary current shaping from an external waveform source.

6Applications

The PCM-7700 suits applications that need controlled, high-current pulses into low-impedance optical loads. Typical uses include:

Laser diode bars and arrays. Up to 200 A into a 25 V load for QCW pumping and high-power diode drive.
Pulsed pump sources. Long-pulse current delivery from 500 µs to 50 ms for solid-state laser pumping.
Diode characterization. Repeatable current pulses with current and voltage monitors for device test and qualification.
Higher duty-cycle test (PCM-7700-EX). External-supply operation where the application calls for sustained pulsing beyond the built-in supply.

7Ordering Information

Part number	Description
PCM-7700-48	Pulsed current source, internal power supply version
PCM-7700-EX	Pulsed current source, external power supply version (higher duty cycles)

A load board and evaluation board are included with each unit. The HPL-2400 low-inductance resistive load used for specification is not included.

Contact

For a quote, configuration help, or application support, reach the Berkeley Nucleonics team.

Email: info@berkeleynucleonics.com
Phone: 800-234-7858

Request the full datasheet. This page summarizes the PCM-7700-48 and PCM-7700-EX specifications. For the complete published datasheet, the per-variant SOA graphs, and a configuration tailored to your system, contact Berkeley Nucleonics.