The BH66F2560 has the characteristics of high functional integration, high accuracy and low noise. For medical conditions such as Silent Hypoxia or cardiopulmonary related diseases, due to severe new coronary pneumonia, this new device can assist product users to monitor their peripheral oxygen (SpO2) saturation level to reduce the risk of severe disease.
Pulse oximeters are non-invasive measurement products that transmit two different light wavelengths, 660nm Red and 940nm Infrared, to the tip of the finger. The transmitted signals through the finger are received using a photodiode. As Oxyhemoglobin (HbO2) and Hemoglobin (Hb) have different light absorption rates for these two different light wavelengths, the measured values can be used to calculate blood oxygen saturation. This new Holtek device includes two constant current sources ranging from 0 to 75mA, which are used to dynamically adjust a programmable current intensity to drive the LED. An integrated blood oxygen signal receiving circuit is used to dynamically adjust a programmable signal gain. An internal 12-bit DAC is used to remove the DC oxygen signals but to retain the AC oxygen signals. The 12-bit ADC is used to sample the blood oxygen signal at high speed. A fully integrated display drive circuit is used to directly drive both LCD and LED panels.