Single-Pulse LED Measurement System
NEWBURYPORT, Mass., May 2, 2012 — Slight differences in LED characteristics can occur during mass production. Sorting the LEDs into bin classes based on luminous flux and color properties provides a means of cataloging them. The LED manufacturer may do the binning, or the party implementing the LEDs may. For higher-efficiency processing, the LED is normally operated and measured in single-pulse mode at a few-milliseconds-long pulse width at a specified operating current.
Gigahertz-Optik Inc. has developed a measurement system consisting of the BTS256-LED tester and LPS-20-1500 LED power supply with S-BTS256 software to assist with single-pulse LED binning.
The meter, power supply and control software work in tandem to drive and measure the test LED in single-pulse mode and to record the results.
The compact BTS256-LED tester is designed to measure luminous flux, and spectral and color data of single assembled and unassembled LEDs in the visible spectrum. Its bi-technology light sensor offers a fine photometric response photodiode for accurate, wide-dynamic-range flux detection. Along with the integral detector, a compact low-stray-light spectrometer is installed for spectral color measurements. The Bi-Tec sensor photodiode is used for pulse form profiling measurements and operates in fast data logger mode with a 1-ms sampling rate. The BTS256-LED is powered through its USB adapter when connected to a PC.
The LPS-20-1500 microprocessor-based current and voltage source operates LEDs and other semiconductor light sources that require low noise. It operates at up to 1500 mA with 30-μA resolution and at up to 24 V with 0.5-mV resolution. It is set up for full remote control operation in continuous-wave or single-pulse mode. Current and voltage can be measured with high 16-bit ADC resolution. Its input-output interface supports trigger-in and trigger-out operation in flash mode.
The S-BTS256-LED software supports setup of the measurement device and source and the synchronized measurement. Calibration and certification of the BTS256-LED tester is performed in the company’s ISO 17025-accredited optical radiation calibration laboratory.