DS1644P

不揮発性タイムキーピングRAM


製品の特定バージョンの最新供給状況はこちらでご確認ください。

説明

The DS1644 is a 32k x 8 nonvolatile static RAM with a full function real time clock, which are both accessible in a byte-wide format. The nonvolatile timekeeping RAM is functionally equivalent to any JEDEC standard 32k x 8 SRAM. The device can also be easily substituted for ROM, EPROM and EEPROM, providing read/write nonvolatility and the addition of the real time clock function. The real time clock information resides in the eight uppermost RAM locations. The RTC registers contain year, month, date, day, hours, minutes, and seconds data in 24-hour BCD format. Corrections for the day of the month and leap year are made automatically. The RTC clock registers are double-buffered to avoid access of incorrect data that can occur during clock update cycles. The double-buffered system also prevents time loss as the timekeeping countdown continues unabated by access to time register data. The DS1644 also contains its own power-fail circuitry, which deselects the device when the VCC supply is in an out-of-tolerance condition. This feature prevents loss of data from unpredictable system operation brought on by low VCC as errant access and update cycles are avoided.
DS1644、DS1644P:標準動作回路 DS1644、DS1644P:標準動作回路 拡大表示+

主な特長

  • Integrated NV SRAM, Real-Time Clock, Crystal, Power-Fail Control Circuit and Lithium Energy Source
  • Clock Registers are Accessed Identically to the Static RAM. These Registers are Resident in the Eight Top RAM Locations.
  • Totally Nonvolatile with Over 10 Years of Operation in the Absence of Power
  • BCD-Coded Year, Month, Date, Day, Hours, Minutes, and Seconds with Leap Year Compensation Valid Up to 2100
  • Power-Fail Write Protection Allows for ±10% VCC Power Supply Tolerance
  • DS1644 Only (DIP Module)
    • Upward Compatible with the DS1643 Timekeeping RAM to Achieve Higher RAM Density
    • Standard JEDEC Bytewide 32k x 8 Static RAM Pinout
  • DS1644P Only (PowerCap Module Board)
    • Surface Mountable Package for Direct Connection to PowerCap Containing Battery and crystal
    • Replaceable Battery (PowerCap)
    • Power-Fail Output
    • Pin-for-Pin Compatible with Other Densities of DS164XP Timekeeping RAM

品質および環境データ

製品の信頼性レポート: DS1644P.pdf 
鉛フリーパッケージの錫(Sn)のウィスカレポート

その他リソース

RTCの計算

CAD Symbols and Footprints

  • DS1644P-120
  • デバイス   ウェハープロセス   プロセス技術   サンプルサイズ   不合格   FIT (25°C)   FIT (55°C)  

    注: 不良率はプロセス技術ごとにまとめられ、関連する型番にマッピングされます。 不良率はテストされたユニット数に大きく依存します。

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