The **PC93H** is a high-speed, high-voltage photoisolator (optocoupler) typically manufactured by Sharp. It is designed to provide electrical isolation between input and output circuits while transferring signals via light, protecting sensitive components from high voltage surges. --- ### ## 1. Key Specifications The PC93H is characterized by its ability to handle high-speed data while maintaining a high isolation voltage. | Parameter | Typical Value | | :--- | :--- | | **Isolation Voltage** | 5,000 Vrms | | **Collector-Emitter Voltage ($V_{CEO}$)** | 35V - 70V (Varies by sub-model) | | **Response Time ($t_r, t_f$)** | High speed (Microsecond range) | | **Forward Current ($I_F$)** | 20mA - 50mA | | **Operating Temperature** | -25°C to +85°C | --- ### ## 2. Internal Electronic Components The device consists of two main semiconductor parts integrated into a single DIP (Dual In-line Package) or SMT (Surface Mount) housing: #### **A. The Input Side: Infrared LED** * **Function:** Converts the incoming electrical signal into light. * **Component:** An AlGaAs (Aluminum Gallium Arsenide) infrared emitting diode. * **Behavior:** When current flows through the LED, it emits photons proportional to the input intensity. #### **B. The Output Side: Phototransistor** * **Function:** Detects light and converts it back into an electrical current. * **Component:** An NPN Silicon Phototransistor. * **Behavior:** When light hits the base of this transistor, it becomes conductive, allowing current to flow from the Collector to the Emitter. --- ### ## 3. Common Applications Because the PC93H provides excellent noise immunity and safety isolation, it is found in: 1. **Switching Power Supplies:** Feedback loops to regulate output voltage while keeping the AC side isolated from the DC side. 2. **Programmable Logic Controllers (PLCs):** Protecting microcontrollers from industrial sensor spikes. 3. **Signal Transmission:** Passing data between circuits with different ground potentials. --- ### ## 4. Pinout Configuration (Standard 6-Pin) | Pin No. | Name | Description | | :--- | :--- | :--- | | 1 | Anode | Positive terminal of the IR LED | | 2 | Cathode | Negative terminal of the IR LED | | 3 | NC | No internal connection | | 4 | Emitter | Transistor Emitter | | 5 | Collector | Transistor Collector | | 6 | Base | Transistor Base (sometimes used for biasing) |