Lz1-led driver

Flickerless LED driver

Copyright (c) 2023-2024 Antmicro

Overview

This project contains open hardware design files for a PCB supporting a pair of infrared (IR) LEDs in an LZ1 LuxiGen package from OSRAM. The PCB includes a flickerless LED driver that allows adjusting LED brightness with a potentiometer. This design can be easily adopted to other LEDs and eventually can become a custom LED driver providing precise lighting for machine vision applications. You can read more about flickerless LED driving in a dedicated blog note. The design files were prepared in KiCad 7.x.

Key features

• LED current driver implemented with MPS/MP2483DQ-LF-P
• Designed for a pair of LZ1-00R802-0000
• Can be daisy-chained with multiple LEDs driven with a single driver

Project structure

The main directory contains KiCad PCB project files, a LICENSE, and a README. The remaining files are stored in the following directories:

• img - contains graphics for this README
• doc - contains schematics in pdf form
• assets - contains visual assets for showcasing this design on Open Hardware Portal.

Usage

The project contains one PCB that can be configured as a primary or a secondary board, depending on the assembly variant. It is designed to be powered with 12V DC using a barrel jack.

Primary board

This version contains the LED driver, all the connectors and a potentiometer.

There are 3 connectors located on the primary board:

• USB-C - outputs 5V without data transfer, only to power an additional device, i.e. a microscope or a camera
• A barrel jack to power the whole circuit with 12V
• A 2-pin JST connector - to daisy chain boards with diodes in serial connection

A rotary potentiometer is the element that provides control of diode brightness using the LED driver.

Secondary board

This variant contains only the LZ1 diodes, 2-pin connectors and resistors marked as secondary DP (R10 and R7). It is powered and controlled by the primary board through JST connectors.

Single board setup

To configure the primary board as a standalone, mount the R7 Debug jumper in addition to R11.

Multi board setup

To daisy chain the boards, R7 CANNOT be populated on the primary board and must be populated on secondary boards. C_out of one board must be connected to A_in of another one. The design was made for up to 3 boards in a chain.

Licensing

This project is published under the Apache-2.0 license.