Photodiode Amplification Module

Hanya modul amplifikasinya saja, tidak termasuk Fotodioda nya PO 30 hari Photodiodes are one of the most commonly used sensor types in many optical measurements. Applications such as absorption and emission spectroscopy, color measurement, turbidity, gas detection, etc. rely on photodiodes for precision optical measurements. The photodiode produces a current that is proportional to the amount of light that is incident on the active area. Transimpedance amplifiers are required for most measurement applications to convert photodiode current to output voltage. The photodiode of this circuit operates in photovoltaic mode where the op amp maintains a voltage of 0 V across the photodiode. This is the most common configuration for precision applications. The voltage-current curve of a photodiode is very similar to a conventional diode, but the entire curve of the former shifts up or down as the light level changes. Figure 2a shows a typical photodiode transfer function. Figure 2b is an enlarged graph of the transfer function, showing that the photodiode outputs a small amount of current even in the absence of light. This dark current rises as the reverse voltage on the photodiode increases. Most manufacturers give the dark current of the photodiode with a reverse voltage of 10 mV. After the light is irradiated onto the active area of ​​the photodiode, current flows from the cathode to the anode. Ideally, all photodiode currents flow through the feedback resistor in Figure 1, producing a feedback voltage equal to the photodiode current multiplied by the feedback resistor. The circuit is simple in principle, but some problems must be solved if the system has the best performance.