The DS1743W-120IND+ is a Y2K compliant, non-volatile timekeeping RAMs in 28 pin EDIP package. This device is a full-function real time clock/calendar (RTC) and 8k x 8 non-volatile static RAM. User access to all registers within the part is accomplished with a byte wide interface. The RTC information and control bits reside in the eight uppermost RAM locations. The RTC registers contain century, year, month, date, day, hours, minutes and seconds data in 24 hour binary coded decimal (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 and prevents time loss as the timekeeping countdown continues unabated by access to time register data. This device contains its own power fail circuitry which deselects device when the VCC supply is in out of tolerance condition.
- Supply voltage range from 2.97V to 3.63V
- Operating temperature range from -40°C to 85°C
- Integrated NV SRAM, real time clock, crystal, power fail control circuit and lithium energy source
- Clock registers are accessed identically to the SRAM, access time is 120ns
- Totally non-volatile with over 10 years of operation in absence of power
- Low battery voltage level indicator flag
- Power fail write protection allows for ±10% VCC power supply tolerance
- Lithium energy source is electrically disconnected to retain freshness
- UL recognized to prevent charging of the internal lithium battery
嵌入式设计与开发
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