# ILX Lightwave LDX-3620 Ultra-Low Noise Current Source (Pre-Owned) # ILX Lightwave LDX-3620 Ultra-Low Noise Current Source (Pre-Owned) ## Key Features At A Glance - Current noise density of 815 pA/√Hz at 1 kHz on the 0–200 mA range (battery operation) - Stability within 10 ppm over 10–30 minutes for narrow-linewidth and stable-wavelength applications - Dual current ranges: 0–200 mA and 0–500 mA, fully floating relative to earth ground - Constant current and constant power operating modes with external photodiode feedback input - External modulation bandwidth to 1 MHz (AC- or DC-coupled) via front-panel isolated BNC - Programmable internal ramp generator with adjustable period from 50 ms to 100 s and rear-panel trigger output - Battery-based design with built-in charger; operates from internal lead-acid batteries or AC line - Redundant front-panel current limit (10–500 mA, ±5 mA accuracy) with slow-start and output-shorting laser protection The ILX Lightwave LDX-3620 is a battery-powered, ultra-low noise laser diode current source optimized for narrow-linewidth and stable-wavelength applications. The instrument provides dual current ranges of 0–200 mA and 0–500 mA with a 4.5-digit LCD display, and it offers constant current or constant power operation, internal or external modulation capability, and a built-in battery charger. The LDX-3620 is positioned by its manufacturer for laboratory work in coherent communications and atomic spectroscopy, where careful attention to current noise and long-term drift directly affects experimental outcomes. Constant current mode switches out unused circuitry so measured output noise approaches the theoretical limits of the control circuit, while constant power mode uses photocurrent from a back-facet monitor photodiode or front-facet power monitor to hold output power steady. The 4.5-digit display combined with coarse and fine output controls allows precise setting of the drive current. ValueTronics International has been a specialist source for laser diode instrumentation and precision test equipment since 1992, with every pre-owned LDX-3620 routed through our 20,000 sq ft secure warehouse at 1675 Cambridge Drive in Elgin, Illinois before it ships. Inventory is held and processed in-house rather than drop-shipped from an unverified third party, which means the unit you order is the unit we have on the shelf, with its condition and accessories documented before quoting. ## Brand Heritage ILX Lightwave was a Bozeman, Montana-based manufacturer of laser diode instrumentation and test systems. The company and its product lines, including the LDX-3620, were acquired by Newport Corporation; Newport itself became part of MKS Instruments through MKS's acquisition of Newport in 2016. Service and documentation for legacy ILX Lightwave instruments are now associated with the MKS/Newport organization. ## Product Core & Specifications Specification 0–200 mA Range 0–500 mA Range OUTPUT Output Current 0–200 mA 0–500 mA Compliance Voltage \>5 V \>4 V Noise and Ripple (5 Hz to 10 MHz bandwidth), Battery operation <850 nA rms <2 µA rms Noise and Ripple (5 Hz to 10 MHz bandwidth), AC line operation <3 µA rms <8 µA rms Noise and Ripple (5 Hz–10 kHz bandwidth), Battery operation <100 nA rms <500 nA rms Noise and Ripple (5 Hz–10 kHz bandwidth), AC line operation <2 µA rms <6.5 µA rms Noise Density at 50/60 Hz 5.2 nA/√Hz 11.5 nA/√Hz Noise Density at 1 kHz (Battery Operation) 815 pA/√Hz 2.6 nA/√Hz Noise Density at 25 kHz (Battery Operation) 315 pA/√Hz 795 pA/√Hz Stability, 10–20 seconds <0.1 ppm <0.1 ppm Stability, 3–5 minutes <1 ppm <1 ppm Stability, 10–30 minutes <10 ppm <10 ppm Temperature Coefficient <10 ppm/°C <10 ppm/°C Transients <10 µA <10 µA Output Connector Shielded 9-pin D-sub on panel Shielded 9-pin D-sub on panel CURRENT LIMIT Range 10–500 mA 10–500 mA Accuracy ±5 mA ±5 mA DISPLAY Type 4.5-digit LCD 4.5-digit LCD Range 0–199.99 0–500.0 Resolution 0.01 mA 0.1 mA Accuracy ±0.05 mA ±0.6 mA Reads LASER diode current in mA; MONITOR photodiode current in mA LASER diode current in mA; MONITOR photodiode current in mA PHOTODIODE FEEDBACK Input Type Current input from external photodiode Current input from external photodiode Range 20 µA to 2 mA for full scale output 20 µA to 2 mA for full scale output Connectors Rear panel isolated BNC jack or 9-pin rear panel D-sub connector Rear panel isolated BNC jack or 9-pin rear panel D-sub connector INTERNAL RAMP GENERATOR Period Adjustable 50 ms to 100 s Adjustable 50 ms to 100 s Span Adjustment 0–200 / 0–500 mA 0–200 / 0–500 mA Ramp Trigger Ramp start trigger output for oscilloscope; optically isolated open collector TTL output Ramp start trigger output for oscilloscope; optically isolated open collector TTL output Ramp Flyback Time 700 µs, approximately 700 µs, approximately EXTERNAL MODULATION INPUT Bandwidth (3 dB point), AC Coupled 100 Hz to 1 MHz 100 Hz to 1 MHz Bandwidth (3 dB point), DC Coupled DC to 1 MHz DC to 1 MHz Transfer Function 100 mA/V 250 mA/V Connector Isolated front panel BNC Isolated front panel BNC GENERAL AC Power Input Voltage Range 100–125 or 210–250 VAC 100–125 or 210–250 VAC Line Frequency 50/60 Hz 50/60 Hz Battery, +12 volt supply 4.5 A-hour sealed lead-acid battery (standard) 4.5 A-hour sealed lead-acid battery (standard) Battery, –12 volt supply 1.2 A-hour sealed lead-acid battery 1.2 A-hour sealed lead-acid battery Operating Temperature 0°C to 40°C 0°C to 40°C Storage Temperature –40°C to 70°C –40°C to 70°C Weight (with extra battery option) 12 kg (26.4 lbs) 12 kg (26.4 lbs) Size (H x W x D) 145 mm x 320 mm x 346 mm (5 5/8" x 12 1/2" x 13 5/8") 145 mm x 320 mm x 346 mm (5 5/8" x 12 1/2" x 13 5/8") **Important:** Output current is fully floating relative to earth ground. Storage temperature range is −40 °C to 70 °C; the datasheet states that batteries should be fully charged before the instrument is subjected to temperature extremes.**Important:** All specification values are measured after a one-hour warm-up period.**Important:** The output is fully floating relative to earth ground.**Important:** To prevent damage, batteries should be fully charged before subjecting the instrument to temperature extremes.Recommended pairing: connect to a laser diode mount using the ILX Lightwave CC-305S Current Source/Laser Diode Mount Interconnect Cable, or use the CC-306S Current Source/Unterminated Interconnect Cable for custom fixtures, as listed in the LDX-3620 ordering information. ## About this used unit - Warranty included - Functional verification included - Standard Calibration Upgrade Options: No Calibration Required, NIST Traceable, Z540.1 or ISO 17025 with Data, Z540.3 Guardbanding with Data. - Note that unnecessary accessories may not be included (contact Test Architect to confirm). **Please review the Manufacturer's Data Sheet to verify published specifications. Feedback on this webpage is always welcome — please reach out to your Test Architect at any time for questions or concerns. Thank you, we truly appreciate you being our customer.** ## Details - **Price:** 0.0 USD - **Vendor:** ILX Lightwave - **Type:** Dc Supply - **Tags:** Current Source, ILX Lightwave, Manufacturers, Other Equipment, Power Supplies & Loads, product_manual_group_2, Product_used ## Variants | Variant | Price | Available | |---------|-------|-----------| | Default Title | 0.00 USD | In stock | ## Images - ILX Lightwave LDX-3620 Ultra-Low Noise Current Source (Pre-Owned) --- > Source: [ValueTronics](https://valuetronics.com/products/ldx-3620-ilx-lightwave-current-source-used) > Updated: 2026-05-30