{"product_id":"bc547c-npn-general-purpose-transistor-to92-45v-100ma-hfe-420-800-50pack","title":"BC547C NPN General-Purpose Transistor — TO-92, 45V, 100mA, hFE 420–800 (50-Pack)","description":"\u003ch2\u003eBC547C NPN General-Purpose Transistor — TO-92, 45V, 100mA, hFE 420–800 (50-Pack)\u003c\/h2\u003e\u003cp\u003eThe BC547C is a high-gain NPN general-purpose transistor in a TO-92 through-hole package, rated at 45V collector-emitter voltage and 100mA continuous collector current. The “C” suffix denotes the highest gain grade (hFE 420–800), making it ideal for low-level signal amplification, audio preamplifiers, and sensitive switching circuits where high current gain is required. It is one of the most widely used small-signal transistors in electronics education and prototyping.\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\u003ePackage\u003c\/td\u003e\n\u003ctd\u003eTO-92 (through-hole)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eType\u003c\/td\u003e\n\u003ctd\u003eNPN silicon transistor\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCollector-Emitter Voltage (VCEO)\u003c\/td\u003e\n\u003ctd\u003e45V\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCollector-Base Voltage (VCBO)\u003c\/td\u003e\n\u003ctd\u003e50V\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eContinuous Collector Current (IC)\u003c\/td\u003e\n\u003ctd\u003e100mA\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDC Current Gain (hFE)\u003c\/td\u003e\n\u003ctd\u003e420–800 (Grade C, at IC=2mA)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTransition Frequency (fT)\u003c\/td\u003e\n\u003ctd\u003e300MHz\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCollector-Emitter Saturation (VCE(sat))\u003c\/td\u003e\n\u003ctd\u003e0.2V typ. (IC=10mA, IB=0.5mA)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOperating Temperature\u003c\/td\u003e\n\u003ctd\u003e-65°C to +150°C\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eQuantity\u003c\/td\u003e\n\u003ctd\u003e50 pieces\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\u003ch3\u003eBC547 Gain Grade Comparison\u003c\/h3\u003e\u003ctable\u003e\n\u003ctr\u003e\n\u003cth\u003eGrade\u003c\/th\u003e\n\u003cth\u003ehFE Range\u003c\/th\u003e\n\u003cth\u003eBest For\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBC547A\u003c\/td\u003e\n\u003ctd\u003e110–220\u003c\/td\u003e\n\u003ctd\u003eGeneral switching, standard gain\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBC547B\u003c\/td\u003e\n\u003ctd\u003e200–450\u003c\/td\u003e\n\u003ctd\u003eGeneral amplification\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBC547C\u003c\/td\u003e\n\u003ctd\u003e420–800\u003c\/td\u003e\n\u003ctd\u003eHigh-gain amplifiers, sensitive circuits\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\u003ch3\u003eWhy Choose BC547C?\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eHigh gain (hFE 420–800)\u003c\/strong\u003e — Grade C provides the highest gain for sensitive amplifier and Darlington pair designs\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e300MHz transition frequency\u003c\/strong\u003e — suitable for audio and low-RF frequency applications\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTO-92 through-hole\u003c\/strong\u003e — breadboard-friendly, easy to prototype and replace\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIndustry-standard pinout\u003c\/strong\u003e — CBE (Collector-Base-Emitter) pin order, compatible with BC548, BC549, 2N3904 (verify pinout)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e50-pack value\u003c\/strong\u003e — sufficient for lab stock, multiple circuit builds, and education\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eCompatible With \/ Common Use Cases\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eArduino GPIO switch\u003c\/strong\u003e: Drive a relay coil (50–100mA) from Arduino 5V GPIO via BC547C base resistor (4.7kΩ)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLED driver\u003c\/strong\u003e: Drive high-brightness LED (20–50mA) from 3.3V MCU GPIO with current limiting\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAudio preamplifier\u003c\/strong\u003e: Common-emitter amplifier stage for microphone or sensor signal conditioning\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDarlington pair\u003c\/strong\u003e: BC547C + BC547C for ultra-high gain (\u0026gt;100,000) in sensitive detector circuits\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOscillator circuit\u003c\/strong\u003e: Colpitts or Hartley oscillator for RF signal generation\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLogic inverter\u003c\/strong\u003e: Simple NOT gate using BC547C as saturating switch\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eQ: How do I calculate the base resistor for BC547C to switch a relay from Arduino?\u003c\/strong\u003e\u003cbr\u003eA: For a 5V relay coil drawing 70mA: IC=70mA, hFE(min)=420. IB(min) = IC\/hFE = 70mA\/420 = 0.17mA. For saturation, use IB = 10×IB(min) = 1.7mA. RB = (VGpio − VBE) \/ IB = (5V − 0.7V) \/ 1.7mA = 2.5kΩ. Use 2.2kΩ standard value. Add a 1N4148 flyback diode across the relay coil.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eQ: What is the difference between BC547 and 2N3904?\u003c\/strong\u003e\u003cbr\u003eA: Both are NPN TO-92 small-signal transistors with similar ratings (45V, 100mA). Key differences: (1) Pinout — BC547 is CBE (left to right), 2N3904 is EBC. Always verify pinout before substituting. (2) hFE — 2N3904 is 100–300 (lower than BC547C). (3) fT — 2N3904 is 300MHz (same). They are functionally interchangeable with pinout adaptation.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eQ: Can BC547C be used for audio amplifier circuits?\u003c\/strong\u003e\u003cbr\u003eA: Yes — BC547C is excellent for audio preamplifier stages. Its high hFE (420–800) and 300MHz fT provide good gain and bandwidth for audio frequencies (20Hz–20kHz). Use in common-emitter configuration with appropriate bias resistors. For output stages driving speakers, use higher-current transistors (BD139, TIP31C).\u003c\/p\u003e\u003ch3\u003ePackage Contents\u003c\/h3\u003e\u003cul\u003e\u003cli\u003e50× BC547C NPN General-Purpose Transistor (TO-92)\u003c\/li\u003e\u003c\/ul\u003e","brand":"Keszoox","offers":[{"title":"Default Title","offer_id":46991462891755,"sku":"\u003cnone\u003e","price":4.28,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0677\/1005\/8731\/files\/bc547c-to92-npn-triode-transistor.webp?v=1761721176","url":"https:\/\/keszoox.com\/products\/bc547c-npn-general-purpose-transistor-to92-45v-100ma-hfe-420-800-50pack","provider":"Keszoox","version":"1.0","type":"link"}