The ILX Lightwave LDX-3525 is a microprocessor-controlled precision current source designed for laser diode control across the LDX-3500B series. It delivers stable, accurate current output in two selectable ranges—200 mA and 500 mA—with exceptional setpoint resolution and accuracy. The instrument operates in three modes: Constant Current (CC) CW for low-bandwidth applications, high-bandwidth CC for modulation up to 500 kHz, and Constant Optical Power (APC) for closed-loop control. Integrated photodiode current measurement (0–5000 µA range, 1 µA resolution) enables direct optical feedback. Multiple laser diode protection circuits—including independent hardware current limits, slow-start turn-on, output shorting relay with semiconductor switch, and adjustable voltage limits—ensure safe, reliable operation in research, development, and production environments.
– Technical Specifications
Output Current
• 200 mA or 500 mA selectable ranges
• Setpoint resolution: 50–100 µA (200 mA) / 125–150 µA (500 mA)
• Setpoint accuracy: ±0.1% of full scale (±0.2 mA / ±0.5 mA)
• Output current accuracy at 25°C: ±0.2 mA (200 mA) / ±0.5 mA (500 mA)
• Temperature coefficient: <50 ppm/°C
• Short-term stability (1 hour): <20 ppm at half-scale
• Long-term stability (24 hours): <50 ppm at half-scale
• Noise and ripple: <2 µA rms (CW) / <4 µA rms (modulation, 100 kHz bandwidth)
Compliance & Power
• Maximum compliance voltage: 7 V
• Input power: 95–125 VAC or 210–250 VAC, 50–60 Hz
Photodiode Measurement
• Current range: 0–5000 µA (0–5.000 mA)
• Resolution: 1 µA
Modulation & Control
• Analog modulation input: Up to 500 kHz (differential input)
• Analog output for remote monitoring
• Calibration: Closed-case via front panel or USB 2.0; data stored in non-volatile memory
– Key Features
• Microprocessor control with three operating modes (CC-CW, CC-HBW, APC)
• Independent hardware current limits with adjustable thresholds
• Slow-start turn-on and output shorting relay (normally closed) plus semiconductor switch
• Power line surge and EFT transient protection
• Intermittent contact protection
– Typical Applications
• Laser diode testing and characterization
• High-speed modulation experiments
• Optical power stabilization
• Production-line laser driver validation
– Compatibility & Integration
USB 2.0 interface for control and calibration management; differential modulation input enables flexible ground configurations for multi-channel test setups.
