Part: DS3231 — Maxim Integrated

Type: I2C Realtime Clock (RTC) with integrated TCXO

Description: A low-cost, extremely accurate I2C realtime clock (RTC) with an integrated temperature-compensated crystal oscillator (TCXO) and crystal, featuring battery backup, two programmable alarms, and a programmable square-wave output.

Operating Conditions:

• Supply voltage: 2.3V to 5.5V (VCC, VBAT)
• Operating temperature: -40°C to +85°C
• I2C clock frequency: Up to 400 kHz (Fast mode)

Absolute Maximum Ratings:

• Max supply voltage: +6.0V (relative to ground)
• Max junction temperature: +125°C

Key Specs:

• Frequency Stability vs. Temperature: ±2ppm (0°C to +40°C, VCC/VBAT = 3.3V)
• Frequency Stability vs. Temperature: ±3.5ppm (-40°C to +85°C, VCC/VBAT = 3.3V)
• Active Supply Current (I CCA): 200 μA max (VCC = 3.63V)
• Timekeeping Battery Current (I BATT): 3 μA max (V BAT = 3.63V)
• Digital Temperature Sensor Accuracy: ±3°C (VCC/VBAT = 3.3V)
• SCL Clock Frequency: 400 kHz (Fast mode)
• Power-Fail Voltage (V PF): 2.45V min, 2.7V max
• Output Frequency: 32.768 kHz

Features:

• Accuracy ±2ppm from 0°C to +40°C
• Accuracy ±3.5ppm from -40°C to +85°C
• Battery Backup Input for Continuous Timekeeping
• 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
• RST Output/Pushbutton Reset Debounce Input
• Underwriters Laboratories (UL) Recognized

Applications:

• Servers
• Utility Power Meters
• Telematics
• GPS

Package:

• 16-pin, 300-mil SO package
• 16 SO

Servers

Utility Power Meters

Telematics

GPS

Functional Diagrams

Pin Configuration appears at end of data sheet.

Functional Diagrams continued at end of data sheet.

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) I 2 C Interface
• ♦ 3.3V Operation
• ♦ Digital Temp Sensor Output: ±3°C Accuracy
• ♦ Register for Aging Trim
• ♦ RST Output/Pushbutton Reset Debounce Input
• ♦ Underwriters Laboratories (UL) Recognized

DS3231 Pinout

Package: 16-pin, 300-mil SO

Notes

• Pin numbers extracted directly from the provided text table (Pin column).
• Pins 5–12 are all No Connection (N.C.) and must be connected to ground.
• Open-drain pins (32kHz, INT/SQW, RST, SDA) require external pullup resistors; pullup voltage can reach 5.5V regardless of VCC voltage.
• RST has an internal 50kΩ pullup to VCC; no external pullup should be added.
• VCC and VBAT should be decoupled with 0.1μF to 1.0μF capacitors.

(VCC = 2.3V to 5.5V, VCC = Active Supply (see Table 1), TA = TMIN to TMAX, unless otherwise noted.) (Typical values are at VCC = 3.3V, VBAT = 3.0V, and TA = +25°C, unless otherwise noted.) (Notes 2, 3)

• INT /SQW Relative to Ground.............................-0.3V to +6.0V

• Junction-to-Ambient Thermal Resistance ( θ JA ) (Note 1)....73°C/W

• Junction-to-Case Thermal Resistance ( θ JC ) (Note 1) ......23°C/W

• Operating Temperature Range

• (noncondensing) .............................................-40°C to +85°C

• Junction Temperature......................................................+125°C

• Lead Temperature (soldering, 10s) .................................+260°C

• Soldering Temperature (reflow, 2 times max) Lead(Pb)-free...............................................................+260°C

• Containing lead(Pb).....................................................+240°C

• (See the Handling, PC Board Layout, and Assembly section.)

Note 1: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a fourlayer board. For detailed information on package thermal considerations, refer to www.maxim-ic.com/thermal-tutorial .

Stresses beyond those listed under 'Absolute Maximum Ratings' may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.

(TA = TMIN to TMAX, unless otherwise noted.) (Notes 2, 3)

For the latest package outline information and land patterns, go to www.maxim-ic.com/packages . Note that a '+', '#', or '' in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status.