{"product_id":"12-mhz-crystal-oscillator-hc-49-s-small-package","title":"12 MHz Crystal Oscillator – HC 49 \/ S Small Package","description":"\u003ch5\u003eOverview \u0026amp; Features\u003c\/h5\u003e\n\u003cp\u003eEvery digital microcontroller needs a precise heartbeat to process instructions accurately. The \u003cstrong\u003e12 MHz Crystal Oscillator (Small Package)\u003c\/strong\u003e provides a highly stable clock signal, making it a foundational component for custom PCB design and digital logic circuits where vertical space is limited.\u003c\/p\u003e\n\n\u003cp\u003eAvailable at Tomson Electronics, this specific crystal comes in the \"Small\" or low-profile \u003cstrong\u003eHC-49\/S\u003c\/strong\u003e package. It offers the exact same electrical performance and reliability as the traditional tall crystals but takes up a fraction of the vertical space, making it perfect for compact, fully enclosed electronic designs. Operating at exactly 12.000 MHz, it is the standard frequency required for popular USB-to-Serial converter chips (like the CH340G) and classic microcontroller architectures like the 8051 and AVR series.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eAlso searched as:\u003c\/strong\u003e 12.000 mhz quartz crystal, hc-49\/s short crystal, small crystal oscillator, low profile 12 mhz clock, smd alternative crystal.\u003c\/p\u003e\n\n\u003chr\u003e\n\n\u003ch5\u003eTechnical Specifications\u003c\/h5\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eNominal Frequency:\u003c\/strong\u003e 12.000 MHz\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePackage Type:\u003c\/strong\u003e HC-49\/S (Short \/ Low profile)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMounting Type:\u003c\/strong\u003e Through-Hole (2-Pin Radial)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFrequency Tolerance:\u003c\/strong\u003e Typically ±20ppm to ±30ppm\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLoad Capacitance:\u003c\/strong\u003e Typically 18pF to 20pF\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eEquivalent Series Resistance (ESR):\u003c\/strong\u003e ≤ 30 to 40 Ohms\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOperating Temperature:\u003c\/strong\u003e -20°C to +70°C\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch5\u003eCommon Applications\u003c\/h5\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eCompact PCB Design:\u003c\/strong\u003e Providing reliable timing for densely packed, space-constrained circuit boards that must fit into slim enclosures.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUSB Interfaces:\u003c\/strong\u003e Clocking USB-to-TTL serial converter ICs like the CH340G, which strictly require a 12 MHz external signal to function.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMicrocontroller Clocks:\u003c\/strong\u003e Acting as the primary external timing signal for 8051, PIC, and AVR microcontrollers.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCommunication Protocols:\u003c\/strong\u003e Ensuring perfectly synchronized baud rates for UART, SPI, and I2C serial communications.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch5\u003eFrequently Asked Questions\u003c\/h5\u003e\n\u003cp\u003e\u003cstrong\u003eQ: What is the difference between this \"Small\" crystal and the \"Big\" ones?\u003c\/strong\u003e\u003cbr\u003e\nA: The difference is entirely physical. This is the low-profile HC-49\/S package, designed to sit closer to the PCB to save vertical space. The \"big\" version is the older HC-49\/U package. Electrically, they perform the exact same function.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eQ: Does it matter which way I plug this in?\u003c\/strong\u003e\u003cbr\u003e\nA: No. Quartz crystals are completely non-polarized components. You can insert the two pins in either direction into your circuit without causing any damage or affecting performance.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eQ: Do I need to use external capacitors with this?\u003c\/strong\u003e\u003cbr\u003e\nA: Yes. In almost all microcontroller applications, you will need to add two small ceramic load capacitors (typically 22pF) connected to ground—one on each pin of the crystal—to ensure the oscillator starts up reliably and remains stable.\u003c\/p\u003e\n\n\u003ch5\u003ePackage Includes\u003c\/h5\u003e\n\u003cul\u003e\n\u003cli\u003e1 × 12 MHz Crystal Oscillator (HC-49\/S Small Package)\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"TOMSON ELECTRONICS","offers":[{"title":"Default Title","offer_id":49516438159598,"sku":"OSC-01986","price":10.0,"currency_code":"INR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/2132\/9029\/files\/12MHz_SMALL_CRYSTAL.jpg?v=1788113961","url":"https:\/\/www.tomsonelectronics.com\/products\/12-mhz-crystal-oscillator-hc-49-s-small-package","provider":"Tomson Electronics ","version":"1.0","type":"link"}