Description
The M41T93 is a low power Serial SPI Bus Real Time Clock with a built-in 32.768kHz oscillator (external crystal-controlled for the QFN16 package, and embedded crystal for the SOX18 package). Eight bytes of the Register Map (see Table 3 on page 18) are used for the clock/calendar function and are configured in binary coded decimal (BCD) format. An additional 17 bytes of the Register Map provide status/control of the two Alarms, Watchdog, 8-Bit Counter, and Square Wave functions. An additional seven bytes are made available as user SRAM.

FEATUREs
■ Ultra-low battery supply current of 365nA
■ Factory calibrated accuracy ±5PPM guaranteed after 2 reflows (SOX18)
  – Much better accuracies achievable using built-in programmable analog and digital calibration circuits
■ 2.0V to 5.5V clock operating voltage
■ Counters for tenths/hundredths of seconds, seconds, minutes, hours, day, date, month, year, and century
■ Automatic switch-over and reset output circuitry (fixed reference)
  –M41T93S: VCC= 3.0V to 5.5V (2.85V≤VRST ≤ 3.00V)
  –M41T93R: VCC= 2.7V to 5.5V (2.55V≤VRST ≤ 2.70V)
  –M41T93Z: VCC= 2.38V to 5.50V (2.25V≤VRST≤2.38V)
■ Compatible with SPI busserial interface (positive clock SPI modes)
■ Programmable alarm with interrupt function (valid even during battery back-up mode)
■ Optional 2nd programmable alarm available
■ Square wave output (defaults to 32kHz on power-up)
■ RESET (RST) output
■ Watchdog timer
■ Programmable 8-bit counter/timer
■ 7 bytes of battery-backed user SRAM
■ Battery low flag
■ Power-down timestamp (HT bit)
■ Low operating current of 80µA
■ Oscillator stop detection
■ Battery or Super-cap™ back-up
■ Operating temperature of –40°C to +85°C
■ Package options include:
  – a 16-lead QFN or an 18-lead embedded crystal SOIC
■ RoHS compliance: lead-free components are compliant with the RoHS directive