The LSM 350 source and measure unit was specifically developed to meet the requirements for production testing of LEDs and LED wafers. This allows all the important parameters of LEDs to be determined quickly and reliably.

Features

• Very short test cycles and parallel electrical measurements
• 0 – 350 mA; 0 – 8 V
• Up to 4 test channels with optional switch matrix
• Dedicated test channel for μA range
• Measurement of breakdown voltage up to 40 V

The current and voltage source is based on a modular concept. The basic 1-channel unit already integrates all the necessary characteristics in a chassis model.

Specifically short settling times provide up to 40% shorter test cycles in comparison to most standard current sources. Automatic polarity identification and reversal ensure that current is supplied to the LED with correct polarity, irrespective of single or multi-chip LED. Dedicated measurement ranges permit particularly precise testing at low forward currents of 1 µA, and measurement of reverse currents in the nA range. All test channels have been designed for 4-wire measurements. Further options facilitate measurement of breakdown voltage up to 40 V.

The LSM 350 shows its special strength when several channels are used for measuring multichip LEDs. Electrical measurements are carried out at precisely the same time on all dies. This considerably shortens the duration of the test cycle compared with other current sources:

Four channels	LSM 350	Rival model
1x optical test at 10 mA	36 ms	67 ms
1x electrical test	35 ms	60 ms
Standard job	218 ms	282 ms

The LSM 350 is optimized for the use with the precise array spectrometers CAS 140CT or CAS 120 from Instrument Systems. The so called LED Tester, a proven turnkey system for LED production testing, can be fitted with an array spectrometer and a LSM-350 current source with up to 4 test channels.