DS1244D

The DS1244D 256k NV SRAM with a Phantom clock is a fully static nonvolatile RAM (NV SRAM)(organized as 32k words by 8 bits) with a built-in real-time clock. The features of DS1244D can be summarized as (1)Real-time clock (RTC) keeps track of hundredths of seconds, minutes, hours, days, date of the month, months, and years; (2)32k x 8 NV SRAM directly replaces volatile static RAM or EEPROM; (3)Embedded lithium energy cell maintains calendar operation and retains RAM data; (4)Watch function is transparent to RAM operation; (5)Month and year determine the number of days in each month; valid up to 2100; (6)Full 10% operating range; (7)Operating temperature range: 0
C to +70
C; (8)Over 10 years of data retention in the absence of power; (9)Lithium energy source is electrically disconnected to retain freshness until power is applied for the first time.

The absolute maximum ratings of the DS1244D are: (1)Voltage Range on Any Pin Relative to Ground: -0.3V to +6.0V; (2)Storage Temperature Range: -40oC to +85oC; (3)Soldering Temperature Range: See IPC/JEDEC J-STD-020A (DIP); (4)Commercial: 0°C to +70°C; (5)Industrial: -40°C to +85°C.

The following is about the electrical characteristics of DS1244D: (1)Input Leakage Current: -1.0A min and +1.0A max; (2)I/O Leakage Current: -1.0A min and +1.0A max; (3)Output Current at 2.4V: -1.0 mA min ; (4)Output Current at 0.4V: 2.0 mA min; (5)Standby Current CE = 2.2V: 5 mA typical and 10 mA max; (6)Standby Current CE = VCC - 0.5V: 3.0 mA typical and 5.0 mA max; (7)Operating Current tCYC = 70ns: 85 mA max; (8)Write Protection Voltage: 4.25V min, 4.37V typical and 4.50 V max; (9)Battery Switchover Voltage: VBAT typical.