This design provides an efficient and visually compelling solution for diverse HMI applications, leveraging advanced LED driver and sensor technologies.
This reference design TIDA-050011 by Texas Instruments (TI) enhances human-machine interface (HMI) applications with an LED ring powered by two LP5024 LED drivers, delivering vivid and dynamic lighting patterns. It effectively addresses challenges commonly faced by devices requiring intricate lighting patterns and a stable voltage supply. Additionally, the design incorporates analog dimming for the LP5024 LED drivers, ensuring consistent contrast ratios even in dynamically changing ambient lighting conditions.
The LP5024 enables high-quality lighting patterns through 12-bit, 29-kHz PWM dimming and is controlled via an I2C interface. Its ultra-low standby current, as low as 10 µA, combined with an automatic power-saving mode, ensures energy efficiency. Programmable RGB banks simplify software control, and the device dynamically adjusts brightness based on ambient light sensing, making it ideal for smart applications. These capabilities make it well-suited for use in devices such as smart speakers with voice assist, appliance user interfaces, video doorbells, electronic smart locks, wearable AR/VR devices, printers, video game consoles, and WLAN/Wi-Fi access points.
At the core of this design is the LP5024, a 24-channel constant current-sink LED driver. It improves user experiences by simplifying color mixing and brightness control, supporting both real-time effects and efficient coding. Its optimized performance for RGB LEDs makes it a prime choice for HMI applications. This functionality is complemented by the SimpleLink™ MSP‑EXP432P401R LaunchPad™ development kit, which facilitates high-performance, low-power operations. The LaunchPad features a 48-MHz Arm® Cortex®-M4F processor, low active power consumption of 80-μA/MHz, and a 660-nA RTC operation, along with advanced features like a 14-bit, 1-MSPS differential SAR ADC and AES256 accelerator. All pins are easily accessible for streamlined integration.
In addition, the OPT3001 sensor measures visible light intensity with a spectral response closely matching the human eye’s photopic response and includes significant infrared rejection. This sensor dynamically adjusts brightness based on ambient lighting, optimizing the LP5024’s analog current and register configurations to generate smooth dimming and vibrant lighting effects.
Two LP5024 drivers manage a 16-RGB-LED module with constant current control and seamless dimming. The ambient light data captured by the OPT3001 sensor enables the MSP‑EXP432P401R LaunchPad to send precise PWM control signals, dynamically adjusting the LP5024 current to create diverse lighting patterns. Power for the LEDs is sourced either from an external DC power supply or the 3.3V output of the LaunchPad. Red LEDs, with a lower forward voltage of 1.8V, reduce power dissipation. Configuration is further supported through jumper settings for enhanced flexibility.
Its lab-verified performance, broad compatibility, and ease of implementation make it an excellent choice for engineers working on high-performance networking and communication systems.TI has thoroughly tested this reference design, ensuring its reliability and performance. The design package includes a bill of materials (BOM), schematics, assembly drawings, printed circuit board (PCB) layouts, and additional resources on the TI website.For more information, click here.
