Application Notes AN0021
SLT3G1 quick LED tester
Abstract:
Application Notes providing a demonstration of how to use the All-in-One Electronic Tester SLT3G1™ to run a quick characterization of discrete LED devices.
Detailed scripts are illustrated in a step by step training suported with videos, sreenshots, electrical schematics and IJ(VJ) curves.
The implemented algorithm allows quick detection of the LED connectivity and starts a LED current sweep in order to extract the LED series DC resistance as well as the LED threshold voltage.
Hardware Requirements:
- SLT3G1 All-in-One tester
- 1 sense resistor (4.7Ω)
- Wiring as per the schematic above
Audience:
- Silicon Validation, Application Engineersengineers,
- Test technicians, operators, white room operator
- Teachers, Researcher, graduate students
All in Video
Documents
Technical details
Description
In this application note, SLT3G1 is exploited to sweep the LED forward current, measure the LED forward voltage and extracts the RS and VTH characteristics.
The algorithm implemented in the application note (downloadable PDF available, AN0021) is the following:
- A cyclic task is used to apply a constant forward current pulse in order to detect the diode or LED connection.
- A high side voltage (4V) is applied to the anode pin of the LED from the DPS channel 1 of SLT3G1
- A sink current is applied to the cathode side by using the low side current generator of SLT3G1
- The forward voltage and forward current are sensed as explained in the schematic above.
- The series The presence of the diode is assessed based on the range of possible VTH and RS series resistance is calculated
- Short current pulses ranging from 0A to 30mA are applied (in order to prevent junction heating) and the forward votlage and forward current are measured.The
- The diode series resistance is then measured based on 2 actual meaurement points above threshold (around 20mA) and the threshold voltage is mathematically calculated based on the derivative starting in the linear forward biased I(V) region.
- Once the RS and VTH are calculated, SLT3G1 is driven to sweep the forward current and store the full forward I(V) characteristic of the diode
- A final PASS/FAIL test is performed to verify if the RS and VTH characteristics fit the datasheet requirements
The scripts provided in the Application Note document AN0021 are suited for FW version 0.9.6 and OS version 0.8.1.
These scripts are intended to be used with copy/paste directly in the script editor.
Feel free to contact us to get the SLRTOS code in .json format (if not made available through this page)
ST3G1 Ressources used
