DS1248/DS1248P 1024K NV SRAM with Phantom Clock

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ZERO BITS

Registers 1, 2, 3, 4, 5, and 6 contain one or more bits, which will always read logic 0. When writing these

locations, either a logic 1 or 0 is acceptable.

BATTERY LONGEVITY

The DS1248 has a lithium power source that is designed to provide energy for clock activity and clock

is sufficient to power the DS1248 continuously for the life of the equipment in which it is installed. For

specification purposes, the life expectancy is 10 years at +25°C with the internal clock oscillator running

lithium energy source is enabled for battery-backup operation. Actual life expectancy of the DS1248 will

See “Conditions of Acceptability” at www.maxim-ic.com/TechSupport/QA/ntrl.htm

CLOCK ACCURACY (DIP MODULE)

The DS1248 is guaranteed to keep time accuracy to within ±1 minute per month at +25°C. The clock is

calibrated at the factory by Maxim using special calibration nonvolatile tuning elements and does not

require additional calibration. For this reason, methods of field clock calibration are not available and not

necessary.

CLOCK ACCURACY (POWERCAP MODULE)

The DS1248P and DS9034PCX are each individually tested for accuracy. Once mounted together, the

module will typically keep time accuracy to within ±1.53 minutes per month (35ppm) at +25°C.