SUMMARY DESCRIPTION
The M41ST85Y/W Serial TIMEKEEPER®/Controller SRAM is a low power 512-bit, static CMOS SRAM organized as 64 words by 8 bits. A built-in 32.768 kHz oscillator (external crystal controlled) and 8 bytes of the SRAM (see Table 2., page 14) are used for the clock/calendar function and are configured in binary coded decimal (BCD) format.
FEATURES SUMMARY
â 5.0 OR 3.0V OPERATING VOLTAGE
â SERIAL INTERFACE SUPPORTS I2C BUS(400 KHz)
â NVRAM SUPERVISOR FOR EXTERNAL LPSRAM
â OPTIMIZED FOR MINIMAL INTERCONNECT TO MCU
â 2.5 TO 5.5V OSCILLATOR OPERATING VOLTAGE
â AUTOMATIC SWITCH-OVER AND DESELECT CIRCUITRY
â CHOICE OF POWER-FAIL DESELECT VOLTAGES
– M41ST85Y: VCC= 4.5 to 5.5V; 4.20V ≤VPFD ≤4.50V
– M41ST85W: VCC= 2.7 to 3.6V; 2.55V ≤VPFD ≤2.70V
â 1.25V REFERENCE (for PFI/PFO)
â COUNTERS FOR TENTHS/HUNDREDTHS OF SECONDS, SECONDS, MINUTES, HOURS, DAY, DATE, MONTH, YEAR, AND
CENTURY
â 44 BYTES OF GENERAL PURPOSE RAM
â PROGRAMMABLE ALARM AND INTERRUPT FUNCTION (VALID EVEN DURING BATTERY BACK-UP MODE)
â WATCHDOG TIMER
â MICROPROCESSOR POWER-ON RESET
â BATTERY LOW FLAG
â POWER-DOWN TIMESTAMP (HT BIT)
â ULTRA-LOW BATTERY SUPPLY CURRENT OF 500nA (MAX)
â PACKAGING INCLUDES A 28-LEAD SOIC AND SNAPHAT® TOP (to be ordered separately)
â SOIC SNAPHAT PACKAGE PROVIDES DIRECT CONNECTION FOR A SNAPHAT TOP WHICH CONTAINS THE BATTERY
AND CRYSTAL
â SOIC EMBEDDED CRYSTAL PACKAGE (MX) OPTION
Fi
Fi
|