Based on your query, it appears you are referring to the **ISCN39P**, which is a specific **NPN Silicon Phototransistor** commonly used in optical sensing and isolation applications. Below is a detailed breakdown of its electronic characteristics and specifications. --- ### 1. Device Overview The ISCN39P is a light-sensitive transistor housed in a side-looking (lateral) package. It is designed to switch or modulate electrical current based on the intensity of incident infrared light. | Feature | Description | | :--- | :--- | | **Type** | NPN Phototransistor | | **Package** | Side-looking (Lateral) Plastic Package | | **Spectral Range** | Optimized for Infrared (approx. 880nm - 950nm) | | **Common Application** | Optical encoders, limit switches, and proximity sensors | --- ### 2. Absolute Maximum Ratings Exceeding these values can lead to permanent damage to the component. | Parameter | Symbol | Maximum Rating | | :--- | :--- | :--- | | Collector-Emitter Voltage | $V_{CEO}$ | 30 V | | Emitter-Collector Voltage | $V_{ECO}$ | 5 V | | Collector Current | $I_C$ | 20 mA | | Power Dissipation | $P_D$ | 100 mW | | Operating Temperature | $T_{OPR}$ | -25°C to +85°C | --- ### 3. Electro-Optical Characteristics These values define how the part performs under standard operating conditions (typically $25^\circ C$). * **Dark Current ($I_{CEO}$):** The leakage current that flows when no light is present. For the ISCN39P, this is typically very low (max 100nA), ensuring a clean "OFF" state. * **Light Current ($I_{C(ON)}$):** The current generated when exposed to a specific irradiance. This is the "ON" state of the transistor. * **Saturation Voltage ($V_{CE(sat)}$):** Usually around 0.4V, indicating how efficiently the transistor acts as a switch. * **Rise/Fall Time ($t_r / t_f$):** Typically in the range of 15 microseconds, defining the switching speed of the sensor. --- ### 4. Pin Configuration and Circuitry As an NPN Phototransistor, it typically has two leads: **Collector** and **Emitter**. The "Base" is the light-sensitive area of the silicon chip itself. #### Typical Application Circuit ```text Vcc (+) | [Resistor R_L] | +---- Output (V_out) | [ ISCN39P ] <--- (Infrared Light Input) | GND (-) ``` --- ### 5. Key Advantages 1. **High Sensitivity:** Small changes in light intensity result in measurable changes in collector current. 2. **Compact Form Factor:** The side-looking package allows for low-profile mounting on PCBs. 3. **Durability:** Solid-state construction with no moving parts. ---