How to Measure Pulsed LED Characteristics

+ PXIe Precision SMU

Measure LED Response With Narrow Pulses

Pulsed light-emitting diode (LED) characterization requires sourcing controlled forward-bias voltage pulses while simultaneously measuring the voltage and resulting device current. The measurement setup can use a four-wire connection with separate force and sense connections between the source measure unit and device fixture. Voltage pulse amplitude is stepped across the required operating points while the pulse width and measurement timing remain controlled.

During each pulse, voltage and current samples are acquired at high speed to capture the transient response of the LED. Using narrow pulses reduces the duration of applied electrical power and helps suppress device self-heating during characterization. The resulting time-domain measurements show the applied voltage pulse together with the corresponding current response, allowing engineers to examine device behavior at different forward-bias levels.

Narrow-Pulse LED Characterization Solution

Pulsed LED characterization requires generating short forward-bias voltage pulses while capturing the corresponding voltage and current response with precise timing. The Keysight PXIe Precision Source / Measure Unit supports pulse widths down to 20 µs and sampling rates up to 1.25 MSa/s. Its digitizing capability captures transient voltage and current during each applied pulse. The application note demonstrates a three-point voltage sweep from 1.5 V to 2.3 V using 20 µs pulses and 800 ns measurement aperture time. A four-wire connection can be used with separate force and sense terminals to perform the pulsed LED measurement.

Get Quote