DS3231S
Realtime Clock (RTC)The DS3231S is a realtime clock (rtc) from Analog Devices. View the full DS3231S datasheet below including key specifications, electrical characteristics, absolute maximum ratings.
Official DS3231S datasheet (PDF) — the source this page was extracted from.
DS3231S Key Specifications
| Parameter | Value |
|---|---|
| Alarms | Two programmable time-of-day alarms |
| Outputs | Programmable square-wave, 32kHz, RST |
| Output Frequency | 32.768kHz |
| Power-Fail Voltage | 2.45V to 2.7V (2.575V typ) |
| Supply Voltage (VCC) | 2.3V to 5.5V |
| Battery Voltage (VBAT) | 2.3V to 5.5V |
| Communication Interface | I2C, up to 400kHz |
| Operating Temperature Range | 0°C to +70°C (commercial) |
| Absolute Maximum Pin Voltage | -0.3V to +6.0V |
| Active Supply Current (VCC=3.63V) | 200µA max |
| Package Thermal Resistance (θJA) | 73°C/W |
| Standby Supply Current (VCC=3.63V) | 110µA max |
| Digital Temperature Sensor Accuracy | ±3°C |
| Timekeeping Accuracy (0°C To +40°C) | ±2ppm |
| Timekeeping Accuracy (>40°C To +70°C) | ±3.5ppm |
| Timekeeping Battery Current (VBAT=3.63V) | 0.84µA typ, 3µA max |
DS3231S Overview
Part: DS3231SN# — Maxim Integrated
Type: Extremely Accurate I2C Real-Time Clock (RTC) with Integrated TCXO
Description: The DS3231 is a low-cost, extremely accurate I2C real-time clock (RTC) with an integrated temperature-compensated crystal oscillator (TCXO) and crystal, offering ±2ppm accuracy from 0°C to +40°C and battery backup for continuous timekeeping.
Operating Conditions:
- Supply voltage: 2.3–5.5 V (VCC or VBAT)
- Operating temperature: -40°C to +85°C (DS3231SN)
- I2C clock frequency: Up to 400 kHz (Fast mode)
Absolute Maximum Ratings:
- Max supply voltage: +6.0 V (relative to ground)
- Max junction temperature: +125°C
- Max storage temperature: -40°C to +85°C
Key Specs:
- Accuracy (0°C to +40°C): ±2 ppm
- Accuracy (-40°C to +85°C): ±3.5 ppm
- Active supply current (VCC = 3.63V): 200 μA (max)
- Timekeeping battery current (VBAT = 3.63V): 3 μA (max)
- Power-fail voltage (VPF): 2.45 V (min) to 2.7 V (max)
- Digital temperature sensor accuracy: ±3°C
- I2C clock frequency: 400 kHz (Fast mode)
- Output frequency: 32.768 kHz
Features:
- Battery Backup Input for Continuous Timekeeping
- 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
- Digital Temp Sensor Output
- Register for Aging Trim
- RST Output/Pushbutton Reset Debounce Input
Applications:
- Servers
- Utility Power Meters
- Telematics
- GPS
Package:
- 16 SO
DS3231S Applications
Servers
Utility Power Meters
Telematics
GPS
Pin Configuration appears 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
DS3231S 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.maximintegrated.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 . |
DS3231S 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 |
- Storage Temperature Range...............................-40°C to +85°C
- Lead Temperature (soldering, 10s) .................................+260°C
- Soldering Temperature (reflow, 2 times max)..................+260°C (See the Handling, PC Board Layout, and Assembly section.)
DS3231S Absolute Maximum Ratings
Voltage Range on Any Pin 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
DS3231S..............................................................0°C to +70°C
DS3231SN ........................................................-40°C to +85°C
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.
DS3231S 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 |
DS3231S Package Information
For the latest package outline information and land patterns (footprints), go to www.maximintegrated.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 |
Variants on the same datasheet
These parts have exact links to the same datasheet. They are candidates to compare, not verified drop-in replacements; check package, pinout and electrical limits.
| Part Number | Manufacturer | Package |
|---|---|---|
| DS3231 | Analog Devices | 16-pin, 300-mil SO |
| DS3231S/T | Analog Devices | SO-16 |
| DS3231SN | Analog Devices | SOIC-16 |
| DS3231SN/T | Analog Devices | SO-16 |
| DS3231SN# | Analog Devices | 16-SOIC (0.295", 7.50mm Width) |
More part numbers on this datasheet
Their pages show this same datasheet. Some are linked through their part family rather than checked part by part, so confirm the exact part in the ordering information.
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