The DS1744W-120 is a Y2K-compliant nonvolatile timekeeping RAM from Analog Devices (formerly Maxim Integrated) that integrates a real-time clock\/calendar, 32KB NV SRAM, crystal, power-fail control circuit, and lithium energy source in an EDIP-28 package. The W suffix denotes 3.3V operation and the -120 indicates 120ns access time. It provides full timekeeping functionality with automatic power-fail detection and battery backup.<\/p>\n
Product Overview The DS1744W-120 is a Y2K-compliant nonvolatile timekeeping RAM from Analog Devices (formerly Maxim Integrated) that integrates a real-time clock\/calendar, 32KB NV SRAM, crystal, power-fail control circuit, and lithium energy source in an EDIP-28 package. The W suffix denotes 3.3V operation and the -120 indicates 120ns access time. It provides full timekeeping functionality with […]<\/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":[13,55],"tags":[],"chip_brand":[165],"class_list":["post-6481","post","type-post","status-publish","format-standard","hentry","category-integrated-circuits-ics","category-transistors","chip_brand-adi"],"acf":{"brief_explanation":"Y2K-compliant 32KB NV SRAM with integrated RTC, crystal, and lithium battery in EDIP-28, 3.3V, 120ns access","date_code":"","package_case":"EDIP-28","in_stock":3250,"datasheet":"https:\/\/www.analog.com\/media\/en\/technical-documentation\/data-sheets\/DS1744-DS1744P.pdf","price":"$26.89","product_introduction":"The DS1744W-120 from Analog Devices is a fully integrated nonvolatile timekeeping RAM that combines 32KB of SRAM, a real-time clock\/calendar, a quartz crystal, power-fail control circuitry, and a lithium energy source in a single EDIP-28 package. The device is Y2K-compliant with a century byte register and automatic leap year compensation through 2100. Clock registers occupy the top eight RAM locations and are accessed identically to SRAM using a standard JEDEC byte-wide interface. When VCC falls below the power-fail threshold, the internal lithium battery automatically maintains RTC operation and SRAM data for over 10 years.","working_principle":"The DS1744W-120 integrates all timekeeping and nonvolatile storage components in a single module. The real-time clock operates from an internal 32.768 kHz crystal oscillator, counting seconds, minutes, hours, days, dates, months, years, and centuries in BCD format. RTC registers are double-buffered to prevent reading corrupted data during clock update cycles. When VCC is above the power-fail threshold (VPF), the device operates normally with full read\/write access to both SRAM and clock registers. When VCC drops below VPF, write protection activates, blocking all access. If VCC falls below the battery switch point (VSO), power switches from VCC to the internal lithium cell, maintaining RTC operation and SRAM data. The power-on reset output signals when VCC returns to valid levels.","pin_description":"
| Pin<\/th> | Name<\/th> | Function<\/th><\/tr> | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1<\/td> | A14<\/td> | Address bit 14<\/td><\/tr> | ||||||||||||
| 2<\/td> | A12<\/td> | Address bit 12<\/td><\/tr> | ||||||||||||
| 3<\/td> | A7<\/td> | Address bit 7<\/td><\/tr> | ||||||||||||
| 4<\/td> | A6<\/td> | Address bit 6<\/td><\/tr> | ||||||||||||
| 5<\/td> | A5<\/td> | Address bit 5<\/td><\/tr> | ||||||||||||
| 6<\/td> | A4<\/td> | Address bit 4<\/td><\/tr> | ||||||||||||
| 7<\/td> | A3<\/td> | Address bit 3<\/td><\/tr> | ||||||||||||
| 8<\/td> | A2<\/td> | Address bit 2<\/td><\/tr> | ||||||||||||
| 22<\/td> | WE<\/td> | Write Enable (active low)<\/td><\/tr> | ||||||||||||
| 27<\/td> | RST<\/td> | Reset output (open drain, active low during power fail)<\/td><\/tr><\/table>","application_scenarios":"The DS1744W-120 is essential in systems requiring reliable time-stamped data storage that survives power loss events. In financial transaction terminals, it maintains transaction logs with accurate timestamps even during power outages. Industrial data logging systems use it to record sensor readings with precise time references. In network equipment, the NV SRAM stores critical configuration data while the RTC maintains accurate time for logging and scheduling. Medical devices benefit from the guaranteed data retention for patient records and calibration timestamps.","alternative_models":"
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