ILX Lightwave LDX-3545: Precision Current Source, 1/3 A, LDX-3500B Series

The ILX Lightwave LDX-3545 is a precision current source for laser diode characterization and operation. It delivers highly stable, low-noise current output across dual ranges - 1 A and 3 A - with setpoint accuracy of ±0.1% of full scale and 1-hour stability better than 20 ppm FS. The instrument operates in constant current and constant power modes, supporting analog modulation up to 50 kHz and photodiode-based feedback for closed-loop power control.

Integrated laser protection includes adjustable current limits, shorting relays, intermittent contact protection, and transient suppression. A five-digit green LED display provides real-time parameter readout, while USB 2.0 connectivity and LabVIEW® drivers enable automated test integration.

Technical Specifications

• Current Output: Dual ranges of 1 A and 3 A


• Setpoint Resolution: 250 µA (1 A range), 750 µA (3 A range)


• Setpoint Accuracy: ±1 mA (1 A range), ±3 mA (3 A range)


• Output Current Stability: <20 ppm FS (1-hour), <50 ppm FS (24-hour)


• Compliance Voltage: 6.5 V (nominal), 6 V at 95 VAC input


• Temperature Coefficient: <50 ppm FS/°C


• Output Noise/Ripple: 15 µA (low bandwidth), 25 µA (high bandwidth)


• Photodiode Current Measurement Range: 5–9999 µA


• Photodiode Reverse Bias: 0–5 V

Key Features

• Constant current and constant power operating modes


• Analog modulation: DC to 50 kHz (standard), DC to 500 kHz (constant current high bandwidth)


• Photodiode current measurement for closed-loop power control


• Current limit clamping prevents overshoot under any condition


• Laser protection: adjustable limits, shorting relays, intermittent contact protection, slow turn-on circuits, transient protection


• Five-digit green LED display - readable with laser safety glasses


• Remote analog output for system monitoring

Typical Applications

• Laser diode characterization and burn-in testing


• Precision power and current control in optical systems


• Closed-loop power regulation via photodiode feedback

Compatibility & Integration

• USB 2.0 interface


• LabVIEW® virtual instrument drivers


• Current source output: 9-pin D-sub female connector


• Analog output: BNC connector


• Operating environment: 10°C to 40°C, <85% RH non-condensing


• Dimensions: 88 mm H × 185 mm W × 304 mm D; Weight: 3.5 kg