M41ST85YMH6E Datasheet PDF - ST Microelectronics

●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

●■ 5.0 OR 3.0V OPERATING VOLTAGE

●■ SERIAL INTERFACE SUPPORTS I2C BUS(400 KHz)

●■ NVRAM SUPERVISOR FOR EXTERNAL LPSRAM

●■ OPTIMIZED FOR MINIMAL INTERCONNECT TO MCU

●■ 2.5 TO 5.5V OSCILLATOR OPERATING VOLTAGE

●■ AUTOMATIC SWITCH-OVER AND DESELECT CIRCUITRY

●■ 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

●■ 1.25V REFERENCE (for PFI/PFO)

●■ COUNTERS FOR TENTHS/HUNDREDTHS OF SECONDS, SECONDS, MINUTES, HOURS, DAY, DATE, MONTH, YEAR, AND

●CENTURY

●■ 44 BYTES OF GENERAL PURPOSE RAM

●■ PROGRAMMABLE ALARM AND INTERRUPT FUNCTION (VALID EVEN DURING BATTERY BACK-UP MODE)

●■ WATCHDOG TIMER

●■ MICROPROCESSOR POWER-ON RESET

●■ BATTERY LOW FLAG

●■ POWER-DOWN TIMESTAMP (HT BIT)

●■ ULTRA-LOW BATTERY SUPPLY CURRENT OF 500nA (MAX)

●■ PACKAGING INCLUDES A 28-LEAD SOIC AND SNAPHAT® TOP (to be ordered separately)

●■ SOIC SNAPHAT PACKAGE PROVIDES DIRECT CONNECTION FOR A SNAPHAT TOP WHICH CONTAINS THE BATTERY

●AND CRYSTAL

●■ SOIC EMBEDDED CRYSTAL PACKAGE (MX) OPTION

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