Datasheet> 器件分类 > 嵌入式处理器和控制器> 微控制器和处理器> M41T81M6F

M41T81M6F: 产品描述日期格式：YY-MM-DD-dd 时间格式：HH:MM:SS:hh (24 hr) 接口类型：I2C, 2-Wire Serial 存储器容量：- 时钟芯片类型：Clock/Calendar; 产品类别嵌入式处理器和控制器微控制器和处理器; 文件大小543KB，共29页; 制造商ST(意法半导体); 官网地址http://www.st.com/

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M41T81M6F在线购买

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M41T81M6F概述

日期格式：YY-MM-DD-dd 时间格式：HH:MM:SS:hh (24 hr) 接口类型：I2C, 2-Wire Serial 存储器容量：- 时钟芯片类型：Clock/Calendar

M41T81M6F规格参数

参数名称	属性值
Brand Name	STMicroelectronics
厂商名称	ST(意法半导体)
零件包装代码	SOIC
包装说明	SOP, SOP8,.25
针数	8
Reach Compliance Code	compliant
ECCN代码	EAR99
Factory Lead Time	10 weeks
Samacsys Description	Real-time Clocks Clock/Calendar I2C, 2-Wire Serial 100uA @ 2V ~ 5.5V SOIC-8_150mil RoHS
最大时钟频率	0.032 MHz
信息访问方法	I2C
中断能力	Y
JESD-30 代码	R-PDSO-G8
JESD-609代码	e4
长度	4.9 mm
湿度敏感等级	1
端子数量	8
计时器数量	1
最高工作温度	85 °C
最低工作温度	-40 °C
封装主体材料	PLASTIC/EPOXY
封装代码	SOP
封装等效代码	SOP8,.25
封装形状	RECTANGULAR
封装形式	SMALL OUTLINE
峰值回流温度（摄氏度）	260
电源	2.5/5 V
认证状态	Not Qualified
座面最大高度	1.75 mm
最大供电电压	5.5 V
最小供电电压	2 V
标称供电电压	5 V
表面贴装	YES
技术	CMOS
温度等级	INDUSTRIAL
端子面层	Nickel/Palladium/Gold (Ni/Pd/Au)
端子形式	GULL WING
端子节距	1.27 mm
端子位置	DUAL
最短时间	1/100 SECOND
处于峰值回流温度下的最长时间	30
易失性	YES
宽度	3.9 mm
uPs/uCs/外围集成电路类型	TIMER, REAL TIME CLOCK

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M41T81

Serial access real-time clock with alarm

Datasheet

production data

Description

SO8

8-pin SOIC

The M41T81 is a low-power serial RTC with a

built-in 32.768 kHz oscillator (external crystal

controlled). Eight bytes of the SRAM are used for

the clock/calendar function and are configured in

binary-coded decimal (BCD) format. An additional

12 bytes of SRAM provide status/control of alarm,

watchdog and square wave functions. Addresses

and data are transferred serially via a two line,

bidirectional I

C interface. The built-in address

WRITE or READ data byte.

The M41T81 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

SRAM and clock operations can be supplied by a

small lithium button supply when a power failure

occurs.

Functions available to the user include a non-

volatile, time-of-day clock/calendar, alarm

interrupts, watchdog timer and programmable

square wave output. 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 - valid until year 2100), 30

and 31 day months are made automatically.

The M41T81 is supplied in an 8-pin SOIC.

Features



For all new designs use M41T81S



Counters for tenths/hundredths of seconds,

seconds, minutes, hours, day, date, month,

year, and century



32 KHz crystal oscillator integrating load

capacitance (12.5 pF) providing exceptional

oscillator stability and high crystal series

resistance operation



Serial interface supports I

C bus (400 kHz

protocol)



Ultra-low battery supply current of 0.6

(typ at 3 V)



2.0 to 5.5 V clock operating voltage



Automatic switchover and deselect circuitry (for

3 V application select M41T81S datasheet)



Power-down time stamp (HT bit) allowing

determination of time elapsed in battery

backup



Programmable alarm and interrupt function

(valid even during battery backup mode)



Accurate programmable watchdog timer (from

62.5 ms to 128 s)



Software clock calibration to compensate

crystal deviation due to temperature



Operating temperature of –40 to 85 °C



ECOPACK

package available

February 2014

This is information on a product in full production.

DocID007529 Rev 11

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www.st.com

Contents

M41T81

Contents

Device overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

2.1

2-wire bus characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

2.1.1

2.1.2

2.1.3

2.1.4

2.1.5

Bus not busy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Start data transfer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Stop data transfer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Data valid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Acknowledge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

2.2

2.3

2.4

READ mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

WRITE mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Data retention mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Clock operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

3.1

3.2

3.3

3.4

3.5

3.6

3.7

3.8

3.9

Power-down time-stamp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Clock registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Calibrating the clock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Setting alarm clock registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Watchdog timer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Square wave output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Century bit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Output driver pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Preferred initial power-on default . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

DC and AC parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Package mechanical information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Part numbering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

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M41T81

List of tables

Table 1.

Table 2.

Table 3.

Table 4.

Table 5.

Table 6.

Table 7.

Table 8.

Table 9.

Table 10.

Table 11.

Table 12.

Table 13.

Table 14.

Table 15.

Table 16.

Signal names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Clock register map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Alarm repeat modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Square wave output frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Preferred default values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Operating and AC measurement conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Capacitance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

DC characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Crystal electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Power down/up AC characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Power down/up trip points DC characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

AC characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

SO8 – 8-lead plastic small outline (150 mils body width), package mechanical data. . . . . 26

Ordering information scheme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Document revision history. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

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List of figures

M41T81

List of figures

Figure 1.

Figure 2.

Figure 3.

Figure 4.

Figure 5.

Figure 6.

Figure 7.

Figure 8.

Figure 9.

Figure 10.

Figure 11.

Figure 12.

Figure 13.

Figure 14.

Figure 15.

Figure 16.

Figure 17.

Logic diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

8-pin SOIC connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Serial bus data transfer sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Acknowledgement sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Slave address location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

READ mode sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Alternative READ mode sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

WRITE mode sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Crystal accuracy across temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Clock calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Alarm interrupt reset waveform. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Backup mode alarm waveform . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

AC measurement I/O waveform . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Power down/up mode AC waveforms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Bus timing requirements sequence. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

SO8 – 8-lead plastic small package outline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

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M41T81M6F

M41T81M6F在线购买

M41T81M6F概述

M41T81M6F规格参数

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