{"product_id":"12-mhz-crystal-oscillator-hc-49-u-large-package","title":"12 MHz Crystal Oscillator – HC 49\/U Large Package","description":"\u003ch5\u003eDescription\u003c\/h5\u003e\n\u003cp\u003eEvery digital microcontroller needs a heartbeat to process instructions accurately. The \u003cstrong\u003e12 MHz Crystal Oscillator\u003c\/strong\u003e provides a highly stable and precise clock signal, making it a foundational component for custom PCB design and digital logic circuits.\u003c\/p\u003e\n\n\u003cp\u003eAvailable at Tomson Electronics, this specific crystal comes in the \"Big\" \u003cstrong\u003eHC-49\/U\u003c\/strong\u003e package. This taller, traditional metallic can is favored by hobbyists and engineers alike because its longer leads and larger body make it incredibly easy to insert into standard breadboards and solder onto through-hole perfboards. Operating at exactly 12.000 MHz, it is the standard frequency required for many 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\/u tall crystal, big crystal oscillator, 12 mhz clock component, microcontroller 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\/U (Tall \/ Large 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\u003eMicrocontroller Clocks:\u003c\/strong\u003e Providing the primary timing signal for 8051, PIC, and AVR microcontrollers on custom development boards.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUSB Interfaces:\u003c\/strong\u003e Clocking USB-to-TTL serial converter ICs like the popular CH340G, which strictly require a 12 MHz external signal to function.\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\u003cli\u003e\n\u003cstrong\u003eDigital Prototyping:\u003c\/strong\u003e Easily plugging into breadboards for testing custom logic timing circuits.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch5\u003eFrequently Asked Questions\u003c\/h5\u003e\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\u003cp\u003e\u003cstrong\u003eQ: What is the difference between this \"Big\" crystal and the \"Short\" ones?\u003c\/strong\u003e\u003cbr\u003e\nA: The difference is purely physical. This is the older, taller HC-49\/U package, while the \"short\" version is the low-profile HC-49\/S package. Electrically, they perform the exact same function, but the taller one is often preferred for breadboarding due to its handling ease.\u003c\/p\u003e\n\n\u003ch5\u003ePackage Includes\u003c\/h5\u003e\n\u003cul\u003e\n\u003cli\u003e1 × 12 MHz Crystal Oscillator (HC-49\/U Large Package)\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"TOMSON ELECTRONICS","offers":[{"title":"Default Title","offer_id":49516432916718,"sku":"OSC-01985","price":10.0,"currency_code":"INR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/2132\/9029\/files\/12_MHz_BIG_CRYSTAL.avif?v=1788113720","url":"https:\/\/www.tomsonelectronics.com\/products\/12-mhz-crystal-oscillator-hc-49-u-large-package","provider":"Tomson Electronics ","version":"1.0","type":"link"}