M41T11 Serial real-time clock (RTC) with 56 bytes of NVRAM

The M41T11is a low power serial real time clock with 56 bytes of NVRAM. A built-in 32.768kHz oscillator (external crystal controlled) and the first 8 bytes of the RAM are used for the clock/calendar function and are configured in binary coded decimal (BCD) format. Addresses and data are transferred serially via a two-line bi-directional bus. The built-in address register is incremented automatically after each write or read data byte.

The M41T11 clock has a built-in power sense circuit which detects power failures and automatically switches to the battery supply during power failures. The energy needed to sustain the RAM and clock operations can be supplied from a small lithium coin cell.

Typical data retention time is in excess of 5 years with a 50mA/h 3V lithium cell. The M41T11 is supplied in 8-lead plastic small outline package or 28 lead SNAPHAT® package.

The 28-pin, 330mil SOIC provides sockets with gold plated contacts at both ends for direct connection to a separate SNAPHAT housing containing the battery and crystal. The unique design allows the SNAPHAT battery package to be mounted on top of the SOIC package after the completion of the surface mount process. Insertion of the SNAPHAT housing after reflow prevents potential battery and crystal damage due to the high temperatures required for device surface-mounting. The SNAPHAT housing is keyed to prevent reverse insertion. The SOIC and battery/crystal packages are shipped separately in plastic anti-static tubes or in tape & reel form.

For the 28-lead SOIC, the battery/crystal package (i.e. SNAPHAT) part number is M4Txx-BR12SH (see Table 16 on page 27).

技术特性

Counters for seconds, minutes, hours, day, date, month, years 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 I²C bus (100 kHz protocol)
Ultra-low battery supply current of 0.8 µA (typ at 3V)
2.0 to 5.5 V clock operating voltage
Automatic switchover and deselect circuitry
56 bytes of general purpose RAM
Software clock calibration to compensate crystal deviation due to temperature
Automatic leap year compensation
Operating temperature of -40 to 85°C
Packaging includes a 28-lead SOIC and SNAPHAT® top (to be ordered separately; 3.3V to 5.0V supply voltage only)
RoHS compliant
- Lead-free second level interconnect

功能框图

M41T11 订购信息

订购型号	产品状态	美金价格	数量	封装	包装形式	温度范围	材料声明
M41T11M6F	Active			SO-8	Tape And Reel	-40 °C-85°C	M41T11M6F
M41T11MH6F	Active			SO-28	Tape And Reel	-40 °C-85°C	M41T11MH6F

DATASHEET

描述	版本	大小
M41T11 : DS1448: Serial real-time clock with 56 bytes of NVRAM	9	245KB

APPLICATION NOTES

描述	版本	大小
AN922: Using a Super Cap to back up the M41T56, M41T00, M41T11, M41T81, M41T94, and M41ST84W (16-pin)	2	85KB
AN923: TIMEKEEPER® rolling into the year 2000 (21st century, Y2K)	1	20KB
AN1012: Predicting the battery life and data retention period of NVRAMs and serial RTCs	4	440KB
AN934: How to use the digital calibration feature in TIMEKEEPER® and serial real-time clock (RTC) products	4	124KB
AN1011: Battery technology used in NVRAM and real-time clock (RTC) products from ST	4	249KB
AN3060: Applications guide for serial real-time clocks	1	355KB

USER MANUALS

描述	版本	大小
UM0276 : STFPC311 LED evaluation board hardware description and user manual	2	503KB