Summary description

The M41T00SC64 is a low power, Serial Real Time Clock plus a 64Kb EEPROM (see Figure 3). A built-in 32,768Hz oscillator (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 M41T00SC64 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 clock operations can be supplied from a small lithium coin cell.

Typical data retention time for the Serial RTC is in excess of 9.5 years with a 50mAh, 3V lithium cell. The M41T00SC64 is supplied in an 18-lead Plastic SOIC package.

Features

■ 2.7V to 5.5V supply voltage

■ I2C bus compatible

■ Operating temperature of –40 to 85°C

■ Packaging includes:

   – 18-lead SOIC (with embedded crystal)

■ RoHS compliant

Serial RTC features (M41T00S)

■ Counters for seconds, minutes, hours, day, date, month, years, and century

■ Embedded crystal package

■ Software clock calibration

■ Factory calibrated to ± 5ppm

■ Automatic power-fail detect and switch-over circuitry

■ Ultra-low battery supply current of 600nA (typ)

■ Automatic leap year compensation

■ Special software programmable output

■ Two-wire I2C serial interface supports 400kHz protocol

Serial EEPROM features (M24C64)

■ 8192 bytes of general purpose EEPROM

   (more than 1E6 erase/write cycles)

■ Two-wire I2C serial interface supports 400kHz protocol

■ Byte and page write (up to 32 bytes)

■ More than 40 year data retention

■ Self-timed programming cycle