Another medical application where the ADuC702x in used is in the measurement of the oxygen saturation of a patient’s blood. A probe is clipped over a patients fingernail which contains two LED sources, one red and one infra-red, facing photodiodes at the other side of the patients finger. The ratio of absorption of the red and infrared light by the photodiode is used to determine the percentage of hemoglobin and oxyhemoglobin in the blood. The ADuC702x is ideal for this application since it can monitor the photodiode outputs via the ADC while the DAC outputs control the LED drive intensity and configure the offset voltage for the external gain amplifier.

