An optical sensing apparatus includes a sensing unit, an analog/digital converting unit, a switching unit, a first processing unit, and a second processing unit. The sensing unit provides a light sensing signal. The analog/digital converting unit is coupled to sensing unit and converts light sensing signal into a digital light sensing signal. The switching unit is coupled to analog/digital converting unit and selectively switched to a first mode or a second mode according to a mode control signal. The first processing unit and second processing unit are coupled to analog/digital converting unit and switching unit respectively. When switching unit is switched to first mode according to mode control signal, first processing unit generates a photoplethysmography (PPG) signal according to digital light sensing signal when switching unit is switched to second mode according to mode control signal, second processing unit generates a proximity sensing signal according to digital light sensing signal.一種光學感測裝置,包括感測單元、類比/數位轉換單元、切換單元、第一及第二處理單元。感測單元提供光感測訊號。類比/數位轉換單元耦接感測單元,並將光感測訊號轉換為數位光感測訊號。切換單元耦接類比/數位轉換單元,並根據模式控制訊號選擇性地切換至第一或第二模式。第一及第二處理單元分別耦接類比/數位轉換單元及切換單元。當切換單元根據模式控制訊號切換至第一模式時,第一處理單元根據數位光感測訊號產生光體積變化描記訊號;當切換單元根據模式控制訊號切換至第二模式時,第二處理單元根據數位光感測訊號產生近接感測訊號。S100~S190‧‧‧流程步驟
