The DS1742W-120+ is an Y2KC (year 2000 compliant) non-volatile timekeeping RAM in 24 pin EDIP package. It includes integrated 2K x 8 non-volatile static RAM, real time clock (RTC), crystal, power fail control circuit and lithium energy source. The lithium energy source is electrically disconnected to retain freshness until power is applied for first time. The RTC registers contain century, year, month, date, day, hours, minutes and seconds data with automatic leap year compensation valid up to year 2100 in 24 hour BCD format. Corrections for day of 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 timekeeping countdown continues unabated by access to time register data. It has standard JEDEC bytewide 2K x 8 static RAM pin-out.
- Supply voltage range from 2.97V to 3.63V
- Operating temperature range from 0°C to 70°C
- Century byte register and supports bytewide interface
- Read and write cycle access time of 120ns
- Non-volatile with over 10 years of operation in the absence of power
- Battery voltage level indicator flag
- Clock registers are accessed identically to static RAM and are resident in eight top RAM locations
- Quartz accuracy of ±1 minute a month at +25°C, factory calibrated
- UL recognized
- Power fail circuitry deselects the device when VCC supply is in an out of tolerance condition
时钟与计时
(EN)
