M41T81S 串行访问实时时钟与警报
The M41T81S is a low power Serial RTC with a built-in 32.768kHz oscillator (external crystal controlled). Eight bytes of the SRAM (see Table 2: Clock register map on page 15) 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, bi-directional I2C interface. The built-in address register is incremented automatically after each WRITE or READ data byte.
The M41T81S 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 supply when a power failure occurs. Functions available to the user include a non-volatile, time-ofday 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 M41T81S is supplied in either an 8-pin SOIC or an 18-pin (MY), 300mil SOIC package which includes an embedded 32kHz crystal.The 18-pin, embedded crystal SOIC requires only a user-supplied battery to provide nonvolatile operation.
M41T81S 订购型号:
| Ordering Model | Package | RoHS Compliance Grade | Marketing Status | Memory Organization | Supply Voltage(Vcc) | Supply Voltage(Vcc) | General Description | Programmable Alarms | Watchdog Timer | Square Wave Output(SQW) | Operating Range | Battery Switchover(VSO) | Battery Low Detect(BL) | Packing Type |
| min | max | |||||||||||||
| V | V | |||||||||||||
| M41T81SM6E | SO8 | Ecopack1 | Active | 160b (20 x 8) | 2 | 5.5 | Serial Access Real-Time Clock with Alarms | Yes | Yes | Yes | Industrial | Yes | Yes | Tube |
| M41T81SM6F | SO8 | Ecopack1 | Active | 160b (20 x 8) | 2 | 5.5 | Serial Access Real-Time Clock with Alarms | Yes | Yes | Yes | Industrial | Yes | Yes | Tape And Reel |
| M41T81SMY6E | SO18 .30 with Embedded Crystal | Ecopack1 | Active | 160b (20 x 8) | 2 | 5.5 | - | Yes | Yes | Yes | Industrial | Yes | Yes | Tube |
| M41T81SMY6F | SO18 .30 with Embedded Crystal | Ecopack1 | Active | 160b (20 x 8) | 2 | 5.5 | - | Yes | Yes | Yes | Industrial | Yes | Yes | Tape And Reel |
M41T81S 产品特性:
- Counters for tenths/hundredths of seconds,seconds, minutes, hours, day, date, month,year, and century
- 32KHz crystal oscillator with integrated loadcapacitance (12.5pf) which provides exceptional oscillator stability and high crystal series resistance operation)
- Oscillator stop detection (monitors clockoperation)
- Serial interface supports I2C bus (400kHz protocol)
- Ultra-low battery supply current of 0.6μA (typ)
- 2.0 to 5.5v clock operating voltage
- Automatic switchover and deselect circuitry (fixed reference) which provides full operation in 3.0V applications)
- VCC = 2.7 to 5.5V
- 2.5V ≤ VPFD ≤ 2.7V
- Power-down time stamp (ht bit) which allows determination of time elapsed in battery backup
- Battery low flag
- Programmable alarm and interrupt function (valid even during battery back-up mode)
- Accurate programmable watchdog timer (from62.5ms to 128s)
- Software clock calibration (to compensate for crystal deviation due to temperature)
- Operating temperature of –40 to 85°C
- Package options include an 8-lead SOIC or 18- lead embedded crystal SOIC
M41T81S 技术支持与电子电路设计开发资源下载
- M41T81S 数据手册DataSheet下载.PDF
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