M41ST87W集成电路（IC）的实时时钟规格书PDF中文资料

M41ST87W属于集成电路（IC）的实时时钟。由意法半导体集团制造生产的M41ST87W实时时钟实时时钟 (RTC) 为几乎所有需要保持精确时间的电子设备提供时间和/或日期信息。时钟类型有二进制计数器、时钟/日历/监控器、历时计时器、幻时钟芯片、便携式系统控制器、温度记录器、时间事件记录器和计时器时钟外设。其包含 2 B 至 2 MB 不等的存储器，接口选项有 I2C、并行、串行、SPI、1 线式、2 线式、3 线式和 4 线式。

特性 Features

• 5.0, 3.3, or 3.0 V operation

• 400 kHz I2C bus

• NVRAM supervisor to non-volatize external LPSRAM

• 2.5 to 5.5 V oscillator operating voltage

• Automatic switchover and deselect circuitry

• Choice of power-fail deselect voltages

− M41ST87Y: (not recommended for new design, contact ST sales office for availability) THS = 1: VPFD≈ 4.63 V; VCC = 4.75 to 5.5 V THS = 0: VPFD≈ 4.37 V; VCC = 4.5 to 5.5 V

− M41ST87W: THS = 1: VPFD ≈ 2.9 V; VCC = 3.0 to 3.6 V THS = 0: VPFD ≈ 2.63 V; VCC = 2.7 to 3.6 V

• Two independent power-fail comparators (1.25 V reference)

• Counters for tenths/hundredths of seconds, seconds, minutes, hours, day, date, month, year, and century

• 128 bytes of clearable, general purpose NVRAM

• Programmable alarm and interrupt function (valid even during battery backup mode)

• Programmable watchdog timer

• Unique electronic serial number (8-byte)

• 32 kHz frequency output available upon power-on

• Microprocessor power-on reset output

• Battery low flag

• Ultra-low battery supply current of 500 nA (typ)

Security features

• Tamper indication circuits with timestamp and RAM clear

• LPSRAM clear function (TPCLR)

• Packaging includes a 28-lead, embedded crystal SOIC and a 20-lead SSOP

• Oscillator stop detection