Abstract: S5821 S5821-01 S5821-02 S5821-03 Text: PHOTODIODE Si PIN photodiode S5821 series High performance, high reliability Si PIN photodiodes S5821 series is a high-speed Si PIN photodiode having high sensitivity over a wide spectral range , ) Si PIN photodiode s Spectral response S5821 series s Directivity 20° (Typ. Ta=25 °C , GHz ...

www.vishay.com Following points mentions difference between photodiode and phototransistor. Photodiode is more responsive to incident light than phototransistor. Photodiode has linear response over much wider range of light than phototransistor. Hence photodiode is used for precise measurement of light over wide range.