V3021- Real Time Clocks - IC

Ultra Low Power 1-Bit 32kHz RTC, 0.8uA standby current.

General Description

The V3021 is a low power CMOS real time clock. Data is transmitted serially as 4 address bits and 8 data bits, over one line of a standard parallel data bus. The device is accessed by chip select (/CS) with read and write control timing provided by either /RD and /WR pulse (Intel CPU) or /DS with advanced R/W (Motorola CPU). Data can also be transmitted over a conventional 3 wire serial interface having CLK, data I/O and strobe. The V3021 has no busy states and there is no danger of a clock update while accessing. Supply current is typically 800nA at VDD = 3.0V. Battery operation is supported by complete functionality down to 2.0V. The oscillator stability is typically 0.3 ppm/V.


  • Utility meters
  • Battery operated and portable equipment
  • Consumer electronics
  • White/brown goods
  • Pay phones
  • Cash registers
  • Personal computers
  • Programmable controller systems
  • Data loggers
  • Automotive electronics


  • Supply current typically 800nA at 3V
  • 50ns access time with 50pF load capacitance
  • Fully operational from 2.0V to 5.5V
  • No busy states or danger of a clock update while accessing
  • Serial communication on one line of a standard parallel data bus or over a conventional 3 wire serial interface
  • Interface compatible with both Intel and Motorola
  • Seconds, minutes, hours, day of month, month, year, week day and week number in BCD format
  • Leap year and week number correction
  • Time set lock mode to prevent unauthorized setting of the current time or date
  • Oscillator stability 0.3 ppm/volt
  • No external capacitor needed
  • Frequency measurement and test modes
  • Temperature range - 40 to +85°C
  • Package
    • SO8
    • DIP8 (End-of-Life, not recommended for new designs)
EM3021 Datasheet (870.68 KB)870.68 KB
Part numberStockMOQPrice
V3021SO8A+Available1$3.01Order now
V3021SO8B+Available on demand--Order now
V3021DL8A+Available on demand--Order now

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