Silicon Labs has introduced an optical heart rate sensing solution designed to reduce the cost and complexity of wrist-based heart rate monitoring (HRM) applications. The Si1144 HRM solution includes a low-power optical sensor module paired with a micro-controller (MCU) running Silicon Labs’ HRM algorithm. The small-footprint (4.9 mm x 2.85 mm x 1.2 mm) Si1144 sensor module integrates an optical sensor, green light-emitting diode (LED), LED drivers supporting up to two external LEDs, an analog-to-digital converter (ADC), control logic, and an I2C digital interface supporting data rates up to 3.4 Mbps. Operating from a 1.71 V to 3.6 V supply voltage, the module draws less than 500 nA standby current, promoting long battery life in wearables.
According to the company, the Si1144 provides a wrist-based HRM solution with accuracy rivaling that of chest-strap-based designs without the inconvenience and comfort issues that chest straps can engender. Wrist-worn designs also allow easy monitoring when running or cycling.
The Si1144 HRM solution targets a wide range of wearable devices including activity-tracking fitness bands, pedometers, and smart watches — in addition to providing HRM capabilities for gym fitness equipment, bathroom scales and geriatric monitoring devices.
Pricing and Availability
Samples and production quantities of the Si1144-AAGX HRM module are available today. The Si1144 module along with Silicon Labs’ HRM algorithm is priced at $2.82 (USD) in 10,000-unit quantities. The HRM44-GGG-PS development board, priced at $57.60 (USD MSRP), enables developers to jump-start evaluation and development of wrist-based HRM applications. To order Si1144 module samples and starter kits, visit www.silabs.com/HRM.