M41ST87W Datasheet, PDF (1/42 Pages) STMicroelectronics – 5.0, 3.3, or 3.0V, 1280 bit (160 x8) Secure Serial RTC and NVRAM Supervisor with Tamper Detection

M41ST87Y
M41ST87W
5.0, 3.3, or 3.0V, 1280 bit (160 x8) Secure Serial RTC
and NVRAM Supervisor with Tamper Detection
FEATURES SUMMARY
■ 5.0, 3.3, OR 3.0V OPERATING VOLTAGE
■ SERIAL INTERFACE SUPPORTS I²C BUS
(400kHz)
■ NVRAM SUPERVISOR FOR EXTERNAL
LPSRAM
■ 2.5 TO 5.5V OSCILLATOR OPERATING
VOLTAGE
■ AUTOMATIC SWITCH-OVER AND
DESELECT CIRCUITRY
■ CHOICE OF POWER-FAIL DESELECT
VOLTAGES
– M41ST87Y:
V_CC = 4.75 to 5.5V;
THS Bit = '1': 4.50V ≤ V_PFD ≤ 4.75V
V_CC = 4.5 to 5.5V;
THS Bit = '0': 4.20V ≤ V_PFD ≤ 4.50V
– M41ST87W:
V_CC = 3.0 to 3.6V;
THS Bit = '1': 2.8V ≤ V_PFD ≤ 3.0V
V_CC = 2.7 to 3.6V;
THS Bit = '0': 2.55V ≤ V_PFD ≤ 2.70V
■ TWO INDEPENDENT POWER-FAIL
COMPARATORS (1.25V REFERENCE)
■ COUNTERS FOR TENTHS/HUNDREDTHS
OF SECONDS, SECONDS, MINUTES,
HOURS, DAY, DATE, MONTH, YEAR, AND
CENTURY
■ 128 BYTES OF GENERAL PURPOSE RAM
■ PROGRAMMABLE ALARM AND
INTERRUPT FUNCTION (VALID EVEN
DURING BATTERY BACK-UP MODE)
■ PROGRAMMABLE WATCHDOG TIMER
■ UNIQUE ELECTRONIC SERIAL NUMBER
(8-BYTE)
■ 32kHz FREQUENCY OUTPUT AVAILABLE
UPON POWER-ON
■ MICROPROCESSOR POWER-ON RESET
■ BATTERY LOW FLAG
■ ULTRA-LOW BATTERY SUPPLY CURRENT
OF 500nA (TYP)
SECURITY FEATURES
■ TAMPER INDICATION CIRCUITS WITH
TIMESTAMP AND RAM CLEAR
■ LPSRAM CLEAR FUNCTION (TP_CLR)
■ PACKAGING INCLUDES A 28-LEAD,
EMBEDDED CRYSTAL SOIC
■ OSCILLATOR STOP DETECTION
Figure 1. Package
EMBEDDED Crystal
28-pin, (300mil)
SOX28 (MX)
March 2006
Rev 6
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