{"id":9793,"date":"2026-07-06T10:50:54","date_gmt":"2026-07-06T10:50:54","guid":{"rendered":"https:\/\/materialparts.com\/x9821wr-03-n0sn\/"},"modified":"2026-07-06T10:50:54","modified_gmt":"2026-07-06T10:50:54","slug":"x9821wr-03-n0sn","status":"publish","type":"post","link":"https:\/\/materialparts.com\/zh\/x9821wr-03-n0sn\/","title":{"rendered":"X9821WR-03-N0SN"},"content":{"rendered":"<h2>\u4ea7\u54c1\u6982\u89c8<\/h2>\n<p>The X9821WR-03-N0SN is an I2C real-time clock (RTC) module from Epson with built-in DTCXO (Digital Temperature Compensated Crystal Oscillator). It provides high-precision timekeeping with automatic leap year adjustment and multiple interrupt functions in a compact surface-mount package.<\/p>\n<h2>\u4e3b\u8981\u89c4\u683c<\/h2>\n<ul>\n<li>Type: Real-Time Clock Module with DTCXO<\/li>\n<li>Manufacturer: Epson<\/li>\n<li>Interface: I2C<\/li>\n<li>Supply Voltage: 1.1V to 5.5V<\/li>\n<li>Frequency Tolerance: +\/-5.0ppm (-40 to +85C)<\/li>\n<li>Backup Current: 0.24uA typical @ 3V<\/li>\n<li>Operating Temp: -40C to +105C<\/li>\n<li>Package: 3.2 x 2.5 x 1.0mm<\/li>\n<li>Time Stamp: 32 events<\/li>\n<li>Functions: Power switching, alarm, time stamp<\/li>\n<li>RoHS: Compliant<\/li>\n<\/ul>\n<h2>\u7279\u70b9<\/h2>\n<ul>\n<li>Built-in DTCXO for +\/-5ppm high stability timekeeping<\/li>\n<li>Ultra-low 0.24uA backup current extends battery life<\/li>\n<li>32 time stamp events for event logging<\/li>\n<li>Automatic power switching between main and backup<\/li>\n<li>I2C interface up to 400kHz<\/li>\n<\/ul>\n<h2>\u5e94\u7528<\/h2>\n<ul>\n<li>Industrial control systems<\/li>\n<li>Smart meters and energy management<\/li>\n<li>Automotive ECUs<\/li>\n<li>Medical equipment timekeeping<\/li>\n<li>IoT device scheduling<\/li>\n<\/ul>","protected":false},"excerpt":{"rendered":"<p>Product Overview The X9821WR-03-N0SN is an I2C real-time clock (RTC) module from Epson with built-in DTCXO (Digital Temperature Compensated Crystal Oscillator). It provides high-precision timekeeping with automatic leap year adjustment and multiple interrupt functions in a compact surface-mount package. Key Specifications Type: Real-Time Clock Module with DTCXO Manufacturer: Epson Interface: I2C Supply Voltage: 1.1V to [&hellip;]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[13,25],"tags":[1067],"chip_brand":[838],"class_list":["post-9793","post","type-post","status-publish","format-standard","hentry","category-integrated-circuits-ics","category-microcontrollers-mcu","tag-x9821wr-03-n0sn","chip_brand-epson"],"acf":{"brief_explanation":"I2C RTC module with DTCXO, +\/-5ppm, 0.24uA backup, 3.2x2.5mm, Epson","date_code":"","package_case":"3.2 x 2.5 x 1.0mm SOP","in_stock":9283,"datasheet":"https:\/\/www5.epsondevice.com\/en\/products\/rtc\/","price":"$1.95 @ 1ku","product_introduction":"The X9821WR-03-N0SN from Epson is an I2C real-time clock module with built-in DTCXO achieving +\/-5ppm frequency stability, ultra-low 0.24uA backup current, and 32 time stamp events in a 3.2x2.5mm package.","working_principle":"The RTC module integrates a 32.768kHz crystal oscillator with a digital temperature compensation circuit (DTCXO) that continuously monitors temperature and adjusts the oscillator frequency to maintain +\/-5ppm accuracy. The I2C interface provides read\/write access to time and date registers. An internal power switching circuit automatically selects between VDD and VBACKUP supplies. Time stamp function records up to 32 events with sub-second resolution.","pin_description":"<table><tr><th>Pin<\/th><th>Name<\/th><th>Function<\/th><\/tr><tr><td>1<\/td><td>SCL<\/td><td>I2C serial clock<\/td><\/tr><tr><td>2<\/td><td>SDA<\/td><td>I2C serial data<\/td><\/tr><tr><td>3<\/td><td>VBACKUP<\/td><td>Backup power supply<\/td><\/tr><tr><td>4<\/td><td>GND<\/td><td>Ground<\/td><\/tr><tr><td>5<\/td><td>VDD<\/td><td>Main power supply (1.1-5.5V)<\/td><\/tr><tr><td>6<\/td><td>EVIN<\/td><td>Event input for time stamp<\/td><\/tr><tr><td>7<\/td><td>IRQ<\/td><td>Interrupt output (alarm\/timestamp)<\/td><\/tr><\/table>","application_scenarios":"<ul><li>Industrial control systems<\/li><li>Smart meters and energy management<\/li><li>Automotive ECUs<\/li><li>Medical equipment timekeeping<\/li><\/ul>","alternative_models":"<table><tr><th>Model<\/th><th>Manufacturer<\/th><th>Key Spec<\/th><th>Package<\/th><\/tr><tr><td>RX8901CE<\/td><td>Epson<\/td><td>I2C DTCXO RTC<\/td><td>3.2x2.5mm<\/td><\/tr><tr><td>DS3231SN<\/td><td>Maxim\/ADI<\/td><td>I2C TCXO RTC<\/td><td>SOIC-16<\/td><\/tr><tr><td>PCF85263A<\/td><td>NXP<\/td><td>I2C RTC<\/td><td>TSSOP-8<\/td><\/tr><\/table>"},"_links":{"self":[{"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/posts\/9793","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/comments?post=9793"}],"version-history":[{"count":0,"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/posts\/9793\/revisions"}],"wp:attachment":[{"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/media?parent=9793"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/categories?post=9793"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/tags?post=9793"},{"taxonomy":"chip_brand","embeddable":true,"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/chip_brand?post=9793"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}