A pulse oximeter is a medical device that indirectly monitors the oxygen saturation and pulse rate of a patient's blood. These portable, battery-operated pulse oximeters are popular in hospitals and clinics.

Renesas’ high integration sensor, the OB1203, is the industry’s smallest optical biosensor module, with a fully integrated biosensor for reflective photoplethysmography. With the appropriate algorithm, it can determine human heart rate, oxygen saturation (SpO2), respiration rate, and heart rate variability. The pulse oximeter transmits this data via an I2C interface to an MCU for system reporting.

Optimized for handheld applications, this design incorporates the RA2A 1, an Arm®-based microcontroller. With its analog support, it can simply implement USB charging of a Li-ion battery, eliminating the need for additional components. Voltage and current can be monitored and controlled with real-time feedback, while charging mode can be adjusted as required.

System Benefits:

  • The OB1203 can be used to achieve the simplest scheme of a rechargeable pulse oximeter for measuring blood oxygen and pulse rate
  • MCU-based lithium battery management, which includes pre-charging, CC, CV charging mode, overcurrent, overvoltage, and overheating protection