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M41T56C64: RTC With EEPROM
8K byteEEPROM combined with Serial Real-Time Clock

M41T56C64 Product Page

Stacked die technology has enabled ST to cost effectively meld EEPROM technology with our low power HCMOS devices to bring a new level in RTC functionality without having to overcome the challenges of fabricating EEPROM and RTC elements on the same die. The M41T56C64, the first device in the series, also integrates the crystal, and allows the user to access, via a two-wire I2C bus, 56 bytes of NVRAM, 8 bytes of clock registers and 8K bytes of EEPROM, all in a single, space saving 18-pin SOIC.






M41T56C64: EEPROM die stacked on an RTC

M41T56C64

Efficient Integration

The embedded crystal means that manual insertion is not required during board assembly and that the crystal is better protected against the corrosive effects of moisture and humidity. Plus, the EEPROM technology allows ST to calibrate each part during manufacturing thus providing a high accuracy of only 5ppm. This accuracy is guaranteed even after reflow. Another great benefit of the stacked die technology is cost. It can be manufactured for only a slight additional cost over monolithic packaging while providing the integration levels of expensive hybrid devices. The real-time clock IC is the M41T56 which draws only 450nA (typical) in backup mode. The EEPROM is ST’s M24C64 with 8192 bytes of memory and more and than 1 million erase/write cycles. Together with the encapsulated 32KHz crystal they form the M41T56C64 with operating specifications of 4.5 to 5.5V and -40°C to +85°C.

M41T56C64
M41T56C64 block diagram

Features
Embedded Crystal package with factory calibration
8K Bytes EEPROM

Applications
The M41T56C64 is targeted at metering applications where accurate timekeeping plus non-volatile data storage is essential. Other applications include medical, vending machines and POS terminals.

Roadmap – M41T00SC64
Following soon will be a 3/3.3V version utilizing the M41T00S RTC. This new device will not have the 56 bytes of NVRAM, but will feature a precision reference for the battery switchover, an oscillator fail detect circuit for capacitor backed applications, and an upgraded I2C interface with 400kHz speed. The M41T00SC64 is scheduled for production by the end of 2006.

 

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