The DS12CR887-33+ from Maxim Integrated (Analog Devices) is a real-time clock with integrated crystal, 114 bytes of battery-backed SRAM, and 4KB of extended SRAM in an EDIP-24 package. The on-chip crystal eliminates external crystal requirements.<\/p>\n
| Interface<\/td>\n | Multiplexed Motorola\/Intel bus<\/td>\n<\/tr>\n | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Time\/Date<\/td>\n | Seconds through year with century<\/td>\n<\/tr>\n | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| SRAM<\/td>\n | 114 bytes (battery-backed) + 4KB extended<\/td>\n<\/tr>\n | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Crystal<\/td>\n | Integrated 32.768kHz<\/td>\n<\/tr>\n | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Alarms<\/td>\n | 3 programmable<\/td>\n<\/tr>\n | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| \u7535\u6e90\u7535\u538b<\/td>\n | 4.5 V to 5.5 V<\/td>\n<\/tr>\n | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| \u5de5\u4f5c\u6e29\u5ea6<\/td>\n | 0C to +70C<\/td>\n<\/tr>\n<\/table>\n\u7279\u70b9<\/h2>\n\u5e94\u7528<\/h2>\nProduct Overview The DS12CR887-33+ from Maxim Integrated (Analog Devices) is a real-time clock with integrated crystal, 114 bytes of battery-backed SRAM, and 4KB of extended SRAM in an EDIP-24 package. The on-chip crystal eliminates external crystal requirements. Key Specifications Interface Multiplexed Motorola\/Intel bus Time\/Date Seconds through year with century SRAM 114 bytes (battery-backed) + 4KB […]<\/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":[13,20],"tags":[],"chip_brand":[165],"class_list":["post-7112","post","type-post","status-publish","format-standard","hentry","category-integrated-circuits-ics","category-interface-ics","chip_brand-adi"],"acf":{"brief_explanation":"RTC with integrated crystal, 114B+4KB SRAM, 3 alarms, EDIP-24, bus interface","date_code":"","package_case":"EDIP-24 (30.48 x 15.24 x 16.00 mm) with integrated crystal","in_stock":8365,"datasheet":"https:\/\/www.analog.com\/en\/products\/ds12cr887.html","price":"$7.50 @ 1ku","product_introduction":"The DS12CR887-33+ from Maxim Integrated (Analog Devices) is a real-time clock with an integrated 32.768kHz crystal in an EDIP-24 package. The device provides complete time and date functions including seconds, minutes, hours, day, date, month, year, and century with automatic leap year correction and daylight saving adjustment. It includes 114 bytes of battery-backed general-purpose SRAM and 4KB of extended SRAM for data storage. Three programmable alarms with interrupt output support complex scheduling. The parallel bus interface supports both Motorola and Intel timing modes for direct connection to microprocessor buses. The integrated crystal simplifies PCB design by eliminating external crystal and load capacitors.","working_principle":"The DS12CR887-33+ integrates RTC, crystal, SRAM, and bus interface in a single module. (1) Oscillator: The integrated 32.768kHz crystal oscillator provides the timebase. The crystal is encapsulated within the package with trimming capacitors, eliminating external components and ensuring reliable startup. (2) RTC: The oscillator drives a counter chain that maintains time and date registers. Century tracking and automatic leap year correction are handled in hardware. (3) Bus Interface: A parallel multiplexed address\/data bus connects to microprocessor buses. The bus supports both Motorola (DS, R\/W) and Intel (RD, WR) timing modes selected via the MOT pin. (4) Battery Backup: An internal lithium cell or external battery maintains timekeeping and SRAM contents when VCC is removed. The internal cell provides approximately 10 years of backup time. (5) Alarms: Three alarm registers can be set for time-of-day, day-of-week, or periodic interrupts.","pin_description":"
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