High-Sensitivity Photodiode for Smartwatch Applications

Full-Scale Entry into the Global Wearable Sector

Photodiodes (PD), the optical sensors used in wearable devices such as smartwatches, are emerging as a key technology in precise biometric signal measurement. As the global wearable market rapidly evolves around healthcare, the importance of sensor performance continues to grow. In response, Korean semiconductor sensor specialist Sigetronics has unveiled a new high-sensitivity, low-power photodiode.

The newly developed device adopts an ultra-compact package to increase sensor integration density. According to the company, it offers stable signal detection even in low-light and low-power environments thanks to its low dark current characteristics.

Noise suppression has been improved to maintain signal accuracy during nighttime or physical activity, and a multi-wavelength process has been applied to enhance detection efficiency in both red and infrared wavelength bands. This enables the device to support advanced biometric applications such as blood oxygen saturation (SpO₂) monitoring.

In particular, the product has been designed to meet quality standards of leading global smartwatch manufacturers. Leveraging this technology, Sigetronics plans to expand its presence into various wearable application markets.

Competition in the global smartwatch market currently includes not only major manufacturers like Apple and Samsung but also numerous Chinese companies. As optical module technologies such as multi-wavelength LED control and signal calibration algorithms continue to advance, demand is increasing for high-sensitivity PDs capable of precise and reliable heart rate and SpO₂ monitoring.

According to IDC, global wearable device shipments in the second quarter of this year reached 136.5 million units, up 9.6% from the same period last year. Industry experts expect that the accuracy and reliability of health-monitoring functions will become key factors in determining future market share.

A Sigetronics representative stated, “The core of wearable devices lies in balancing accurate signal detection with low power consumption. Based on our semiconductor process technology and sensor design capabilities, we will accelerate our expansion into the global market.”

Meanwhile, as smartwatch functions evolve from simple health monitoring to personalized healthcare platforms, Sigetronics is also exploring ways to extend its photodiode technology to next-generation wearables such as wireless earbuds.

EDaily, November 6, 2025