DS3231

Extremely Accurate I²C-Integrated RTC/TCXO/Crystal


Description

The DS3231 is a low-cost, extremely accurate I²C real-time clock (RTC) with an integrated temperature-compensated crystal oscillator (TCXO) and crystal. The device incorporates a battery input, and maintains accurate timekeeping when main power to the device is interrupted. The integration of the crystal resonator enhances the long-term accuracy of the device as well as reduces the piece-part count in a manufacturing line. The DS3231 is available in commercial and industrial temperature ranges, and is offered in a 16-pin, 300-mil SO package.

The RTC maintains seconds, minutes, hours, day, date, month, and year information. The date at the end of the month is automatically adjusted for months with fewer than 31 days, including corrections for leap year. The clock operates in either the 24-hour or 12-hour format with an active-low AM/PM indicator. Two programmable time-of-day alarms and a programmable square-wave output are provided. Address and data are transferred serially through an I²C bidirectional bus.

A precision temperature-compensated voltage reference and comparator circuit monitors the status of VCC to detect power failures, to provide a reset output, and to automatically switch to the backup supply when necessary. Additionally, the active-low RST pin is monitored as a pushbutton input for generating a µP reset.
DS3231: Typical Operating Circuit DS3231: Typical Operating Circuit Enlarge+

Key Features

  • Accuracy ±2ppm from 0°C to +40°C
  • Accuracy ±3.5ppm from -40°C to +85°C
  • Battery Backup Input for Continuous Timekeeping
  • Operating Temperature Ranges
    • Commercial: 0°C to +70°C
    • Industrial: -40°C to +85°C
  • Low-Power Consumption
  • Real-Time Clock Counts Seconds, Minutes, Hours, Day, Date, Month, and Year with Leap Year Compensation Valid Up to 2100
  • Two Time-of-Day Alarms
  • Programmable Square-Wave Output
  • Fast (400kHz) I²C Interface
  • 3.3V Operation
  • Digital Temp Sensor Output: ±3°C Accuracy
  • Register for Aging Trim
  • Active-Low RST Output/Pushbutton Reset Debounce Input

Applications/Uses

  • Global Positioning Systems (GPS)
  • Servers
  • Telematics
  • Utility Power Meters
Part Number Freq. Osc. Type Tuning Adjustment Type Freq. Output Type Frequency Stability
(±ppm/yr)
Frequency Stability
(±ppm/yr)
Frequency Stability
(±ppm/yr)
Frequency Stability
(±ppm)
VSUPPLY
(V)
Budgetary
Price
0 to +40°C -40 to 0°C/ +40 to +85°C vs. VCC vs. Aging See Notes
DS3231  32.768kHz TCXO Digital CMOS Open-Drain 2 3.5 1 (typ) 5 (0-10 Years) 2.3 to 5.5 $3.85 @1k
See All Oscillator Modules (24)

Part Number Interface VSUPPLY
(V)
Time Keeping Current
(nA)
Memory Type Time of Day Alarms Integrated Resonator Budgetary
Price
typ See Notes
DS3231  I2C 2.3 to 5.5 840 None 2 XTAL $3.85 @1k
See All Timekeeping & Real-Time Clocks (84)
Pricing Notes:
This pricing is BUDGETARY, for comparing similar parts. Prices are in U.S. dollars and subject to change. Quantity pricing may vary substantially and international prices may differ due to local duties, taxes, fees, and exchange rates. For volume-specific and version-specific prices and delivery, please see the price and availability page or contact an authorized distributor.


MAXPMBAE: Maxim Analog Essentials Collection of Peripheral Modules

Tools & Models

DS3231 IBIS Model

 

Related Resources