{"product_id":"pc817-el817-optocoupler-dip4-5kv-isolation-5pack","title":"PC817 \/ EL817 Optocoupler DIP-4 Phototransistor Output 5kV Isolation (5-Pack)","description":"\u003ch2\u003ePC817 \/ EL817 Optocoupler — DIP-4, 5kV Isolation, Phototransistor Output (5-Pack)\u003c\/h2\u003e\u003cp\u003eThe \u003cstrong\u003ePC817\u003c\/strong\u003e (also sold as EL817, FL817C, PS817C) is the world’s most widely used general-purpose optocoupler in a \u003cstrong\u003eDIP-4\u003c\/strong\u003e through-hole package. It provides \u003cstrong\u003e5kV AC isolation\u003c\/strong\u003e between input (LED) and output (phototransistor), making it essential for MCU-to-relay isolation, SMPS feedback loops, and any circuit requiring galvanic separation between control and power sections.\u003c\/p\u003e\u003ch3\u003eKey Specifications\u003c\/h3\u003e\u003ctable\u003e\n\u003ctr\u003e\n\u003cth\u003eParameter\u003c\/th\u003e\n\u003cth\u003eValue\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePart Number\u003c\/td\u003e\n\u003ctd\u003ePC817 \/ EL817 \/ FL817C \/ PS817C\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePackage\u003c\/td\u003e\n\u003ctd\u003eDIP-4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eIsolation Voltage\u003c\/td\u003e\n\u003ctd\u003e5,000V AC (1 minute)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCTR (Current Transfer Ratio)\u003c\/td\u003e\n\u003ctd\u003e50–300% @ IF=5mA (Grade C: 100–300%)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eInput LED Forward Voltage\u003c\/td\u003e\n\u003ctd\u003e1.2V typical @ IF=20mA\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eInput LED Current (IF max)\u003c\/td\u003e\n\u003ctd\u003e50mA\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOutput Transistor VCEO\u003c\/td\u003e\n\u003ctd\u003e80V\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOutput Transistor IC max\u003c\/td\u003e\n\u003ctd\u003e50mA\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eResponse Time (rise\/fall)\u003c\/td\u003e\n\u003ctd\u003e~4μs \/ ~3μs\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOperating Temperature\u003c\/td\u003e\n\u003ctd\u003e−30°C to +100°C\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eQuantity\u003c\/td\u003e\n\u003ctd\u003e5 pieces\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\u003ch3\u003ePC817 Grade Selection\u003c\/h3\u003e\u003ctable\u003e\n\u003ctr\u003e\n\u003cth\u003eGrade\u003c\/th\u003e\n\u003cth\u003eCTR Range\u003c\/th\u003e\n\u003cth\u003eMarking\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eA\u003c\/td\u003e\n\u003ctd\u003e50–100%\u003c\/td\u003e\n\u003ctd\u003ePC817A\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eB\u003c\/td\u003e\n\u003ctd\u003e100–200%\u003c\/td\u003e\n\u003ctd\u003ePC817B\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eC\u003c\/td\u003e\n\u003ctd\u003e200–300%\u003c\/td\u003e\n\u003ctd\u003ePC817C\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eD\u003c\/td\u003e\n\u003ctd\u003e300–600%\u003c\/td\u003e\n\u003ctd\u003ePC817D\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\u003ch3\u003eWhy Choose PC817?\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e5kV Isolation\u003c\/strong\u003e — Meets IEC 60950 and UL safety requirements for mains-isolated circuits\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUniversal Replacement\u003c\/strong\u003e — PC817, EL817, FL817C, PS817C are all electrically identical and pin-compatible\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e80V Output Transistor\u003c\/strong\u003e — Suitable for relay drive, optoisolated gate drive, and signal isolation\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDIP-4 Package\u003c\/strong\u003e — Breadboard-friendly, easy to prototype and replace\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIndustry Standard\u003c\/strong\u003e — Used in virtually every SMPS, inverter, and industrial control board\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eTypical Applications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eMCU-to-relay galvanic isolation (Arduino controlling 230V relay)\u003c\/li\u003e\n\u003cli\u003eSMPS optoisolated feedback loop (flyback converter output regulation)\u003c\/li\u003e\n\u003cli\u003eRS-232\/RS-485 signal isolation\u003c\/li\u003e\n\u003cli\u003eAC zero-crossing detection circuit\u003c\/li\u003e\n\u003cli\u003eIsolated gate drive for TRIAC and SCR\u003c\/li\u003e\n\u003cli\u003eIndustrial PLC I\/O isolation\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eTypical Circuit (MCU to Relay)\u003c\/h3\u003e\u003cp\u003eMCU GPIO → 330Ω resistor → PC817 LED anode (pin 1). LED cathode (pin 2) → GND. Phototransistor collector (pin 4) → relay coil + pull-up to VCC. Emitter (pin 3) → GND.\u003c\/p\u003e\u003ch3\u003eFAQ\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eQ: What resistor value for PC817 LED with 5V MCU GPIO?\u003c\/strong\u003e\u003cbr\u003eA: R = (5V − 1.2V) \/ 10mA = 380Ω. Use 390Ω standard value. For 3.3V: R = (3.3V − 1.2V) \/ 10mA = 210Ω, use 220Ω.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eQ: Can PC817 switch AC signals?\u003c\/strong\u003e\u003cbr\u003eA: No — the output phototransistor is a DC device. For AC switching isolation, use a TRIAC optocoupler (MOC3021, MOC3041).\u003c\/p\u003e\u003ch3\u003ePackage Contents\u003c\/h3\u003e\u003cul\u003e\u003cli\u003e5× PC817 \/ EL817 DIP-4 Optocoupler\u003c\/li\u003e\u003c\/ul\u003e","brand":"Keszoox","offers":[{"title":"Default Title","offer_id":46991497036011,"sku":"\u003cnone\u003e","price":5.6,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0677\/1005\/8731\/files\/pc817-optocoupler-dip4.webp?v=1761535492","url":"https:\/\/keszoox.com\/products\/pc817-el817-optocoupler-dip4-5kv-isolation-5pack","provider":"Keszoox","version":"1.0","type":"link"}