DS3231S#

Realtime Clock (RTC)

The DS3231S# is a realtime clock (rtc) from Analog Devices Inc./Maxim Integrated. View the full DS3231S# datasheet below including key specifications, electrical characteristics, absolute maximum ratings.

Manufacturer

Analog Devices Inc./Maxim Integrated

Key Specifications

Parameter	Value
Current - Timekeeping (Max)	110µA ~ 170µA @ 3.63V ~ 5.5V
Date Format	YY-MM-DD-dd
DigiKey Programmable	Not Verified
Features	Alarm, Leap Year, Square Wave Output, TCXO/Crystal
Interface	I2C, 2-Wire Serial
Mounting Type	Surface Mount
Operating Temperature	0°C ~ 70°C
Package / Case	16-SOIC (0.295", 7.50mm Width)
Supplier Device Package	16-SOIC
Time Format	HH:MM:SS (12/24 hr)
Type	Clock/Calendar
Supply Voltage	2.3V ~ 5.5V
Voltage - Supply, Battery	2.3V ~ 5.5V

Overview

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

Applications

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

Pin Configuration

PIN	NAME	FUNCTION
1	32kHz	32kHz Output. This open-drain pin requires an external pullup resistor. When enabled, the output operates on either power supply. It may be left open if not used.
2	V CC	DC Power Pin for Primary Power Supply. This pin should be decoupled using a 0.1μF to 1.0μF capacitor. If not used, connect to ground.
3	INT /SQW	Active-Low Interrupt or Square-Wave Output. This open-drain pin requires an external pullup resistor connected to a supply at 5.5V or less. This multifunction pin is determined by the state of the INTCN bit in the Control Register (0Eh). When INTCN is set to logic 0, this pin outputs a square wave and its frequency is determined by RS2 and RS1 bits. When INTCN is set to logic 1, then a match between the timekeeping registers and either of the alarm registers activates the INT /SQW pin (if the alarm is enabled). Because the INTCN bit is set to logic 1 when power is first applied, the pin defaults to an interrupt output with alarms disabled. The pullup voltage can be up to 5.5V, regardless of the voltage on V CC . If not used, this pin can be left unconnected.
4	RST	Active-Low Reset. This pin is an open-drain input/output. It indicates the status of V CC relative to the V PF specification. As V CC falls below V PF , the RST pin is driven low. When V CC exceeds V PF , for t RST , the RST pin is pulled high by the internal pullup resistor. The active-low, open-drain output is combined with a debounced pushbutton input function. This pin can be activated by a pushbutton reset request. It has an internal 50k nominal value pullup resistor to V CC . No external pullup resistors should be connected. If the oscillator is disabled, t REC is bypassed and RST immediately goes high.
5-12	N.C.	No Connection. Must be connected to ground.
13	GND	Ground
14	V BAT	Backup Power-Supply Input. When using the device with the V BAT input as the primary power source, this pin should be decoupled using a 0.1μF to 1.0μF low-leakage capacitor. When using the device with the V BAT input as the backup power source, the capacitor is not required. If V BAT is not used, connect to ground. The device is UL recognized to ensure against reverse charging when used with a primary lithium battery. Go to www.maxim-ic.com/qa/info/ul .
15	SDA	Serial Data Input/Output. This pin is the data input/output for the I 2 C serial interface. This open-drain pin requires an external pullup resistor. The pullup voltage can be up to 5.5V, regardless of the voltage on V CC .
16	SCL	Serial Clock Input. This pin is the clock input for the I 2 C serial interface and is used to synchronize data movement on the serial interface. Up to 5.5V can be used for this pin, regardless of the voltage on V CC .

Electrical Characteristics

(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)

PARAMETER	SYMBOL	CONDITIONS	CONDITIONS	MIN	TYP	MAX	UNITS
Active Supply Current	I CCA	(Notes 4, 5)	V CC = 3.63V			200	μA
Active Supply Current	I CCA	(Notes 4, 5)	V CC = 5.5V			300	μA
Standby Supply Current	I CCS	I 2 C bus inactive, 32kHz output on, SQW output off (Note 5)	V CC = 3.63V			110	μA
Standby Supply Current	I CCS	I 2 C bus inactive, 32kHz output on, SQW output off (Note 5)	V CC = 5.5V			170	μA
Temperature Conversion Current	I CCSCONV	I 2 C bus inactive, 32kHz output on, SQW output off	V CC = 3.63V			575	μA
Temperature Conversion Current	I CCSCONV	I 2 C bus inactive, 32kHz output on, SQW output off	V CC = 5.5V			650	μA
Power-Fail Voltage	V PF			2.45	2.575	2.7	V
Logic 0 Output, 32kHz, INT /SQW, SDA	V OL	I OL = 3mA	I OL = 3mA			0.4	V
Logic 0 Output, RST	V OL	I OL = 1mA	I OL = 1mA			0.4	V
Output Leakage Current 32kHz, INT /SQW, SDA	I LO	Output high impedance	Output high impedance	-1	0	1	μA
Input Leakage SCL	I LI			-1		1	μA
RST Pin I/O Leakage	I OL	RST high impedance (Note 6)	RST high impedance (Note 6)	-200		10	μA
V BAT Leakage Current (V CC Active)	I BATLKG				25	100	nA

Absolute Maximum Ratings

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.

Recommended Operating Conditions

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

PARAMETER	SYMBOL	MIN	TYP	MAX	UNITS
Supply Voltage	V CC	2.3	3.3	5.5	V
Supply Voltage	V BAT	2.3	3	5.5	V
Logic 1 Input SDA, SCL	V IH	0.7 x V CC		V CC + 0.3	V
Logic 0 Input SDA, SCL	V IL	-0.3		0.3 x V CC	V

Package Information

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.

PACKAGE TYPE	PACKAGE CODE	OUTLINE NO.	LAND PATTERN NO.
16 SO	W16#H2	21-0042	90-0107

Related Variants

The following components are covered by the same datasheet.

Part Number	Manufacturer	Package
DS3231	Analog Devices / Maxim Integrated	16-pin, 300-mil SO
DS3231S	Analog Devices / Maxim Integrated	—
DS3231SN	Analog Devices / Maxim Integrated	—
DS3231SN#	Analog Devices Inc./Maxim Integrated	16-SOIC (0.295", 7.50mm Width)

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