This design enables design engineers to accelerate development, optimize power consumption, and ensure high signal integrity in next-generation biometric systems.
It is a compact optical heart rate monitor reference design that meets the rising need for reliable, low-power biometric sensing in wearable and portable devices. For design engineers, it delivers a proven hardware architecture that reduces development risk and speeds time-to-market for PPG-based heart rate measurement. As fitness trackers, smartwatches, medical patches, and remote monitoring systems grow in demand, accurate optical sensing becomes essential. This validated design can be easily adapted and optimized for battery-powered products while meeting size, power, and signal integrity requirements.
At the core of the TIDA-00301 from Texas Instruments is an optical sensing front end that uses LEDs and a photodiode to detect changes in blood volume beneath the skin surface. The reflected light intensity varies with each heartbeat, and these small analog signals are captured and processed to extract pulse information. Signal conditioning and digitization are handled by the AFE4403, an integrated analog front end specifically developed for optical heart rate and pulse oximeter applications. This device provides programmable LED current drivers, transimpedance amplification, ambient light cancellation, filtering, and a high-resolution ADC, significantly reducing external component count and board space while improving measurement accuracy.
System control and signal processing are managed by the MSP430F5528, a 16-bit ultra-low-power microcontroller from TI’s MSP430 family. The MCU configures the AFE timing sequences, collects digitized data, executes filtering and heart rate calculation algorithms, and manages communication with external host systems. Its low-power operating modes are essential for battery-powered wearable applications, helping extend operational life while maintaining continuous monitoring capability.
The reference design package provides comprehensive documentation and hardware resources to support rapid prototyping and product customization. Available materials include a detailed design guide describing system architecture and measured performance data, complete schematics for circuit replication or modification, PCB layout files and Gerbers for manufacturing, and a full bill of materials (BOM) with component specifications. These assets allow design engineers to import the project into standard EDA tools and adapt it to their own mechanical, electrical, and regulatory requirements.
From a hardware design perspective, careful PCB layout is critical due to the sensitivity of optical measurements. Proper grounding, decoupling, separation of analog and digital domains, and shielding from ambient light sources are necessary to maintain signal integrity. Power optimization strategies, including controlled LED drive currents and effective use of MCU low-power modes, are equally important for wearable implementations. Engineers integrating this design into commercial products should also consider firmware refinement, wireless connectivity options such as Bluetooth Low Energy, and compliance with relevant medical or consumer electronics standards. Overall, TIDA-00301 serves as a validated and scalable foundation for compact biometric sensing systems.
TI has tested this reference design. It comes with a bill of materials (BOM), schematics, assembly drawing, printed circuit board (PCB) layout, and more. The company’s website has additional data about the reference design. To read more about this reference design, click here.
