Ultra-compact Chip LED to enable more precise heart rate measurement in in-ear devices

The enhanced Chip LED from ams OSRAM delivers higher brightness—while taking up barely more space than a grain of sand. Perfect for integration into everyday devices like in-ear headphones or smart rings.

Premstaetten, Austria, and Munich, Germany (April 14, 2025) – The measurement of heart rate in wearable devices continues to be refined for even greater precision. ams OSRAM introduces a new miniaturized Chip LED, featuring a powerful 500 µm chip that delivers enhanced signal quality. Measuring just 1.2 mm x 1.0 mm x 0.6 mm—barely larger than a grain of sand—this ultra-compact LED yet delivers an impressive light output of 14 mW.

The Chip LED from ams OSRAM offers around 20 percent higher brightness compared to its predecessor model, in an even more compact design enabling more efficient photoplethysmography (PPG). 
This technology measures changes in blood volume in the vessels by emitting green light into the skin and analyzing the reflected signals. A more powerful light source, such as the new Chip LED from ams OSRAM, significantly boosts measurement accuracy, especially in accessories such as smart rings or in-ear devices worn on well-perfused body limbs. 

At the same time, this enhanced efficiency helps reduce energy consumption—a crucial advantage for battery-powered devices designed for long-term use.

“ams OSRAM has demonstrated its expertise in vital sign monitoring over many years and is now further driving the trend toward miniaturization with its high-performance products”, explains Florian Lex, Product Marketing Manager at ams OSRAM. “Our new Chip LED enables more reliable heart rate monitoring, even in devices that are designed to be unobtrusive yet highly precise.”

Continuous monitoring of vital signs is gaining increasingly in importance—in both medical and fitness settings. Since fingers and earlobes have better blood circulation than the wrist, components placed in these areas of the body provide particularly accurate data. The new green single emitter CT ELLN51.14 of the Chip LED family from ams OSRAM now enables these precise measurements even in extremely compact designs, perfectly aligning with the increasing toward high-performance, unobtrusive wearables.

ams OSRAM has a long-standing track record of successfully developing compact, high-performance LEDs. This is reflected in more than 1,500 granted patents and other intellectual property rights, protecting the achievements of ams OSRAM in the field of green emitters. An additional 200 patent rights in the field of vital sign monitoring highlight deep expertise of ams OSRAM in this promising technology.

For vital sign monitoring devices, ams OSRAM offers a comprehensive portfolio beyond LEDs, including proximity sensors that can detect when headphones are in the ear, thereby supporting energy-saving functions.

Information about the product portfolio for vital sign monitoring can be found here. 

More information about the new Chip LED is available here.