The PC817C is an optocoupler (also cal LED an optoisolator), commonly used for signal isolation in electronic circuits. This component is typically produced by Sharp Corporation, though other manufacturers may also produce similar parts under the same or different part numbers.
Pin Function Specifications and Circuit Principle
The PC817 C optocoupler comes in the DIP-4 package, meaning it has 4 pins. Here’s a detailed explanation of the pins and their functions:
Pin No. Pin Name Description Pin 1 Anode (LED side) This pin is connected to the anode of the LED inside the optocoupler. When a voltage is applied to this pin, the LED inside the optocoupler emits light. Pin 2 Cathode (LED side) This pin is connected to the cathode of the LED. It is the return path for the current flowing through the LED. Pin 3 Collector (Photo transistor side) This pin connects to the collector of the phototransistor. It is used to read the signal that has been transferred via light from the LED side. Pin 4 Emitter (Phototransistor side) This pin connects to the emitter of the phototransistor. It is typically connected to ground or the negative side of the load in the circuit.PC817C Detailed Pin Function Explanation
Pin 1 - Anode (LED side): This pin connects to the positive side of the LED inside the optocoupler. To activate the optocoupler, a forward voltage must be applied to this pin (typically between 1.2V to 1.4V). In circuits, Pin 1 is usually connected to a current-limiting resistor and a driving voltage (such as from a microcontroller). Pin 2 - Cathode (LED side): This pin is connected to the negative side of the LED and serves as the return path for the current flowing through the LED. It is often tied to the ground or negative voltage in the circuit, completing the circuit for the LED's operation. Pin 3 - Collector (Phototransistor side): This pin connects to the collector of the phototransistor. When the LED inside the optocoupler is turned on, it emits light, which activates the phototransistor, allowing current to flow from the collector to the emitter. This pin typically connects to a load or is used as the output for the signal transferred via the optocoupler. Pin 4 - Emitter (Phototransistor side): This pin is connected to the emitter of the phototransistor. It is typically grounded or connected to the negative side of the load in the circuit. When the phototransistor is activated by the LED, current flows from the collector to the emitter, thereby transferring the signal to the output side.Package Information
The PC817C typically comes in a 4-pin DIP (Dual In-line Package) form factor. The 4 pins are arranged in a straight line, and the package usually has a small rectangular shape. The LED side is electrically isolated from the phototransistor side, providing signal isolation between input and output circuits.
FAQs
Here’s a collection of 20 common questions and answers regarding the PC817C optocoupler:
What is the typical forward voltage of the LED in the PC817C? The typical forward voltage of the LED in the PC817C is around 1.2V to 1.4V at a current of 10mA. What is the maximum forward current for the LED? The maximum forward current for the LED in the PC817C is typically 50mA. What is the maximum collector-emitter voltage for the phototransistor? The maximum collector-emitter voltage for the phototransistor in the PC817C is 80V. What is the maximum current transfer ratio (CTR) of the PC817C? The maximum current transfer ratio (CTR) for the PC817C can be up to 300%. Can the PC817C be used for high-speed switching applications? The PC817C is not suitable for high-speed switching due to its slower response time. It's typically used for general-purpose signal isolation. What is the isolation voltage of the PC817C? The isolation voltage for the PC817C is typically 5kV RMS. Can the PC817C be used in power supply applications? Yes, the PC817C can be used in power supply applications for isolating low-voltage control signals from high-voltage circuits. What is the typical application of the PC817C? The PC817C is commonly used for signal isolation between a microcontroller and external circuitry, as well as in switching and feedback circuits. What is the operating temperature range of the PC817C? The operating temperature range for the PC817C is typically -30°C to +100°C.Can the PC817C be used for switching DC signals?
Yes, the PC817C is designed for switching DC signals, but its switching speed is limited compared to other optocouplers designed for high-speed applications.What is the typical response time for the PC817C?
The typical rise and fall time for the PC817C is around 4µs to 6µs.What is the typical transfer characteristic of the PC817C?
The PC817C typically has a current transfer ratio (CTR) of 50% to 600%, depending on the operating conditions and load.How should the PC817C be mounted on a circuit board?
The PC817C is typically mounted in a through-hole (DIP-4) configuration, and the pins should be soldered to the PCB for stable operation.What type of load can be driven by the phototransistor side?
The phototransistor side of the PC817C can typically drive loads such as microcontrollers, relays, and low-power switching devices.What is the pinout of the PC817C?
The pinout of the PC817C is as follows: Pin 1: Anode (LED side) Pin 2: Cathode (LED side) Pin 3: Collector (Phototransistor side) Pin 4: Emitter (Phototransistor side)What is the maximum power dissipation for the PC817C?
The maximum power dissipation for the PC817C is around 100mW.Can the PC817C be used for both AC and DC signals?
The PC817C can handle both AC and DC signals but is primarily designed for DC signal isolation.What is the recommended current-limiting resistor for the LED side?
The recommended current-limiting resistor for the LED side is typically calculated based on the input voltage and desired LED current, often around 330Ω to 1kΩ.Can the PC817C be used for logic level shifting?
Yes, the PC817C can be used for level shifting between circuits operating at different voltage levels, as it provides electrical isolation.What is the typical application in microcontroller interfacing?
The PC817C is often used in microcontroller interfacing for isolating control signals, protecting the microcontroller from high voltages, and ensuring safe signal transfer between components.Let me know if you need any further information or explanations on the PC817C optocoupler!
