M41T82数据手册集成电路（IC）的实时时钟规格书PDF

描述 Description

The M41T8x are low-power serial I2C real-time clocks (RTCs) with a built-in 32.768 kHz oscillator (external crystal-controlled for the QFN16 and SO8 packages, embedded crystal for the SOX18 package). Eight bytes of the register map (see Table 2 on page 23) are used for the clock/calendar function and are configured in binary-coded decimal (BCD) format. An additional 17 bytes of the register map provide status/control of the two alarms, watchdog, 8-bit counter, and square wave functions. An additional seven bytes are made available as user SRAM.

Addresses and data are transferred serially via a two-line, bidirectional I2C interface. The built-in address register is incremented automatically after each WRITE or READ data byte. The M41T8x has a built-in power sense circuit which detects power failures and automatically switches to the battery supply when a power failure occurs. The energy needed to sustain the clock operations can be supplied by a small lithium button battery when a power failure occurs.

Functions available to the user include a non-volatile, time-of-day clock/calendar, two alarm interrupts, watchdog timer, programmable 8-bit counter, and square wave outputs. The eight clock address locations contain the century, year, month, date, day, hour, minute, second, and tenths/hundredths of a second in 24-hour BCD format. Corrections for 28, 29 (leap year), 30, and 31 day months are made automatically. The M41T83 is supplied in either a QFN16 or an SOX18, 300 mil SOIC which includes an embedded 32 KHz crystal. The SOX18 package requires only a user-supplied battery to provide non-volatile operation. The M41T82 is available only in an SO8 package.

特性 Features

• Ultra-low battery supply current of 365 nA
• Factory-calibrated accuracy of ±5 ppm typical after 2 reflows (SOX18)
•Much better accuracies achievable using built-in programmable analog and digital calibration circuits
• 2.0 V to 5.5 V clock operating voltage
• Counters for tenths/hundredths of seconds, seconds, minutes, hours, day, date, month, year, and century
• Automatic switchover and reset output circuitry (fixed reference)
•M41T83S: VCC= 3.00 V to 5.50 V
•M41T83R: VCC= 2.70 V to 5.50 V
•M41T83Z: VCC= 2.38 V to 5.50 V
• Serial interface supports I2C bus (400 kHz protocol)
• Programmable alarm with interrupt function (valid even during battery backup mode)
• Optional 2ndprogrammable alarm available
• Square wave output defaults to 32 KHz on power-up (M41T83 only)
• RESET (RST) output
• Watchdog timer
• Programmable 8-bit counter/timer
• 7 bytes of battery-backed user SRAM
• Battery low flag
• Low operating current of 80 μA
• Oscillator stop detection
• Battery or SuperCap™ backup
• Operating temperature of –40 °C to 85 °C
• Package options
•a 16-lead QFN (M41T83)
•an 8-lead SOIC (M41T82) or
•an 18-lead embedded crystal SOIC (M41T83)
• RoHS compliance: lead-free components are compliant with the RoHS directive

简介

M41T82属于集成电路（IC）的实时时钟。由制造生产的M41T82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。