SPI-Compatible RTC in a TDFN

Please check latest availability status for a specific part variant.


The MAX6902 SPI™-compatible real-time clock contains a real-time clock/calendar and 31 x 8 bits of static random-access memory (SRAM). The real-time clock/calendar provides seconds, minutes, hours, day, date, month, year, and century information. A time/date programmable polled ALARM is included in the MAX6902. The end-of-the-month date is automatically adjusted for months with fewer than 31 days, including corrections for leap year up to the year 2100. The clock operates in either the 24hr or 12hr format with an AM/PM indicator. The MAX6902 operates with a supply voltage of +2V to +5.5V, is available in the ultra-small 8-pin TDFN package, and works over the -40°C to +85°C industrial temperature range.
MAX6902: Typical Operating Circuit MAX6902: Typical Operating Circuit Enlarge+

Key Features

  • Real-Time Clock Counts Seconds, Minutes, Hours, Day of Week, Date of Month, Month, Year, and Century
  • Leap-Year Compensation Valid up to Year 2100
  • +2V to +5.5V Wide Operating Voltage Range
  • SPI Interface: 4MHz at 5V; 1MHz at 2V
  • 31 x 8-Bit SRAM for Scratchpad Data Storage
  • Uses Standard 32.768kHz, 12.5pF Watch Crystal
  • Low Timekeeping Current (400nA at 2V)
  • Single-Byte or Multiple-Byte (Burst Mode) Data Transfer for Read or Write of Clock Registers or SRAM
  • Ultra-Small 8-Pin 3mm x 3mm x 0.8mm TDFN Package
  • Programmable Time/Date Polled ALARM Function
  • No External Crystal Bias Resistors or Capacitors Required


  • Battery-Powered Products
  • Fax Machines
  • Intelligent Instruments
  • Point-of-Sale Equipment
  • Portable Instrumentation

Additional Resources

RTC Calculator
Product Reliability Reports: MAX6902.pdf 
Device   Fab Process   Technology   Sample size   Rejects   FIT at 25°C   FIT at 55°C   Material Composition  

Note : The failure rates are summarized by technology and mapped to the associated material part numbers. The failure rates are highly dependent on the number of units tested.

Quality Management System >
Environmental Management System >


Related Resources

±5ppm, I2C Real-Time Clock with Integrated MEMS Oscillator

  • Highly Accurate RTC with Integrated MEMS Resonator Completely Manages All Timekeeping Functions
  • 64-Byte RAM for User Data Storage
  • Simple Serial Interface Connects to Most Microcontrollers