DS3231 Maxim, DS3231 Datasheet
DS3231
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DS3231 Summary of contents
Page 1
... 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. ...
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... 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 ...
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Extremely Accurate I ELECTRICAL CHARACTERISTICS (continued 2.3V to 5.5V Active Supply (see Table 1 3.3V 3.0V, and T = +25°C, unless otherwise noted.) (Notes 2, 3) BAT A PARAMETER SYMBOL Output ...
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Extremely Accurate I RTC/TCXO/Crystal AC ELECTRICAL CHARACTERISTICS ( CC(MIN) CC(MAX) BAT PARAMETER SYMBOL SCL Clock Frequency Bus Free Time Between STOP and START Conditions Hold Time (Repeated) START t HD:STA Condition ...
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Extremely Accurate I RST PF(MAX PF(MIN) t VCCF RST _____________________________________________________________________ 2 C-Integrated RTC/TCXO/Crystal Pushbutton Reset Timing t RST Power-Switch Timing VCCR t REC 5 ...
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... Note 8: A device must internally provide a hold time of at least 300ns for the SDA signal (referred to the V to bridge the undefined region of the falling edge of SCL. Note 9: The maximum t needs only to be met if the device does not stretch the low period (t ...
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... V ( GND -10 -20 -30 - DELTA TIME AND FREQUENCY vs. TEMPERATURE DS3231 toc05 20 0 CRYSTAL -20 +20ppm -40 TYPICAL CRYSTAL, -60 UNCOMPENSATED -80 -100 DS3231 CRYSTAL ACCURACY -120 -20ppm BAND -140 -160 -180 -200 -40 -30 -20 - TEMPERATURE (°C) _____________________________________________________________________ ...
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... ADDRESS REGISTER DECODE SDA 8 _____________________________________________________________________ 2 C-Integrated CONTROL LOGIC/ SQUARE-WAVE BUFFER; DIVIDER INT/SQW CONTROL 1Hz TEMPERATURE ALARM, STATUS, AND SENSOR CONTROL REGISTERS 1Hz CLOCK AND CALENDAR VOLTAGE REFERENCE; DEBOUNCE CIRCUIT; PUSHBUTTON RESET DS3231 Block Diagram 32kHz N INT/SQW N REGISTERS USER BUFFER (7 BYTES RST N ...
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... SCL movement on the serial interface 5.5V can be used for this pin, regardless of the voltage on V Detailed Description The DS3231 is a serial RTC driven by a temperature- compensated 32kHz crystal oscillator. The TCXO pro- vides a stable and accurate reference clock, and maintains the RTC to within ±2 minutes per year accu- racy from -40° ...
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... DS3231 continues to monitor the RST line. ( the line is still low, the DS3231 continuously monitors the line looking for a rising edge. Upon detecting ACTIVE SUPPLY release, the DS3231 forces the RST pin low and holds it V BAT low for t RST V CC RST is also used to indicate a power-fail condition ...
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... DATA 0 Note: Unless otherwise specified, the registers’ state is not defined when power is first applied. Figure 1 shows the address map for the DS3231 time- keeping registers. During a multibyte access, when the address pointer reaches the end of the register space (12h), it wraps around to location 00h ...
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... The countdown chain is reset whenever the seconds regis- ter is written. Write transfers occur on the acknowledge from the DS3231. Once the countdown chain is reset, to avoid rollover issues the remaining time and date registers must be written within 1 second. The 1Hz square-wave out- put, if enabled, transitions high 500ms after the seconds data transfer, provided the oscillator is already running ...
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... Control Register (0Eh) Bit 7: Enable Oscillator (EOSC). When set to logic 0, the oscillator is started. When set to logic 1, the oscilla- tor is stopped when the DS3231 switches to V bit is clear (logic 0) when power is first applied. When the DS3231 is powered the oscillator is always CC on regardless of the status of the EOSC bit ...
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... The initial power-up state of this bit is logic 1, and a 32.768kHz square-wave signal appears at the 32kHz pin after a power source is applied to the DS3231 (if the oscillator is running). Bit 2: Busy (BSY). This bit indicates the device is busy executing TCXO functions. It goes to logic 1 when the ...
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... SCL input and open-drain SDA I/O lines. Within the bus specifications, a standard mode (100kHz maximum clock rate) and a fast mode (400kHz maximum clock rate) are defined. The DS3231 works in both modes. The following bus protocol has been defined (Figure 2): • ...
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Extremely Accurate I RTC/TCXO/Crystal MSB FIRST SDA SLAVE R/W ADDRESS SCL 1–7 8 IDLE START CONDITION 2 Figure Data Transfer Overview slave by not generating an acknowledge bit on the last byte that has been clocked out ...
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... A MASTER TO SLAVE SLAVE TO MASTER acknowledging the transfer. The master may then transmit zero or more bytes of data, with the DS3231 acknowledging each byte received. The register pointer increments after each data byte is trans- ferred. The master generates a STOP condition to terminate the data write. ...
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... Extremely Accurate I RTC/TCXO/Crystal Handling, PC Board Layout, and Assembly The DS3231 package contains a quartz tuning-fork crystal. Pick-and-place equipment can be used, but precautions should be taken to ensure that excessive shocks are avoided. Ultrasonic cleaning should be avoided to prevent damage to the crystal. Avoid running signal traces under the package, unless ...
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Extremely Accurate I REVISION REVISION NUMBER DATE 0 1/05 Initial release. Changed Digital Temp Sensor Output from ±2°C to ±3°C. Updated Typical Operating Circuit. 1 2/05 Changed T A Updated Block Diagram. Added “UL Recognized” to Features; added lead-free packages ...
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... Register (0Eh) section; added the land pattern no. to the Package Information table. Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. ...