DS3231数据手册(DS3231).pdf-资料库

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DS3231 Extremely Accurate I2C-Integrated RTC/TCXO/Crystal Features General 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 accu- rate timekeeping when main power to the device is inter- rupted. 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 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 refer- ence 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 nec- essary. Additionally, the RST pin is monitored as a pushbutton input for generating a µP reset. Applications Servers Telematics Utility Power Meters GPS Pin Configuration appears at end of data sheet. o Accuracy ±2ppm from 0°C to +40°C o Accuracy ±3.5ppm from -40°C to +85°C o Battery Backup Input for Continuous Timekeeping o Operating Temperature Ranges Commercial: 0°C to +70°C Industrial: -40°C to +85°C o Low-Power Consumption o Real-Time Clock Counts Seconds, Minutes, Hours, Day, Date, Month, and Year with Leap Year Compensation Valid Up to 2100 o Two Time-of-Day Alarms o Programmable Square-Wave Output o Fast (400kHz) I2C Interface o 3.3V Operation o Digital Temp Sensor Output: ±3°C Accuracy o Register for Aging Trim o RST Output/Pushbutton Reset Debounce Input o Underwriters Laboratories (UL) Recognized Ordering Information TEMP RANGE 0°C to +70°C -40°C to +85°C PART DS3231S# DS3231SN# #Denotes an RoHS-compliant device that may include lead (Pb) that is exempt under RoHS requirements. The lead finish is JESD97 category e3, and is compatible with both lead- based and lead-free soldering processes. A "#" anywhere on the top mark denotes an RoHS-compliant device. PIN-PACKAGE 16 SO 16 SO Typical Operating Circuit VCC SCL SDA RST µP VCC RPU = tR/CB RPU RPU PUSHBUTTON RESET VCC VCC DS3231 GND INT/SQW 32kHz VBAT N.C. N.C. N.C. N.C. SCL SDA RST N.C. N.C. N.C. N.C. For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim Integrated’s website at www.maximintegrated.com. 19-5170; Rev 9; 1/13

DS3231 Extremely Accurate I2C-Integrated RTC/TCXO/Crystal ABSOLUTE MAXIMUM RATINGS Voltage Range on Any Pin Relative to Ground......-0.3V to +6.0V Junction-to-Ambient Thermal Resistance (θJA) (Note 1)....73°C/W Junction-to-Case Thermal Resistance (θJC) (Note 1) ......23°C/W Operating Temperature Range DS3231S ..............................................................0°C to +70°C DS3231SN ........................................................-40°C to +85°C Junction Temperature......................................................+125°C 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 Assemblysection.) Note 1: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four- layer 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 CONDITIONS Supply Voltage Logic 1 Input SDA, SCL Logic 0 Input SDA, SCL VCC VBAT VIH VIL TYP 3.3 3.0 MIN 2.3 2.3 0.7 x VCC -0.3 MAX 5.5 5.5 VCC + 0.3 0.3 x VCC UNITS V V V V 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 MIN TYP Active Supply Current ICCA (Notes 4, 5) 2.45 2.575 -1 -1 -200 0 25 MAX 200 300 110 170 575 650 2.70 0.4 0.4 +1 +1 +10 100 UNITS μA μA μA V V V μA μA μA nA Maxim Integrated VCC = 3.63V VCC = 5.5V VCC = 3.63V VCC = 5.5V I2C bus inactive, 32kHz output on, SQW output off (Note 5) I2C bus inactive, 32kHz VCC = 3.63V output on, SQW output off VCC = 5.5V IOL = 3mA IOL = 1mA Output high impedance RST high impedance (Note 6) Standby Supply Current ICCS Temperature Conversion Current ICCSCONV Power-Fail Voltage Logic 0 Output, 32kHz, INT/SQW, SDA Logic 0 Output, RST Output Leakage Current 32kHz, INT/SQW, SDA Input Leakage SCL RST Pin I/O Leakage VBAT Leakage Current (VCC Active) 2 VPF VOL VOL ILO ILI IOL IBATLKG

DS3231 Extremely Accurate I2C-Integrated RTC/TCXO/Crystal ELECTRICAL CHARACTERISTICS (continued) (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 MIN Output Frequency fOUT VCC = 3.3V or VBAT = 3.3V Frequency Stability vs. Temperature (Commercial) Frequency Stability vs. Temperature (Industrial) f/fOUT f/fOUT VCC = 3.3V or VBAT = 3.3V, aging offset = 00h VCC = 3.3V or VBAT = 3.3V, aging offset = 00h 0°C to +40°C >40°C to +70°C -40°C to <0°C 0°C to +40°C >40°C to +85°C Frequency Stability vs. Voltage f/V Trim Register Frequency Sensitivity per LSB f/LSB Specified at: -40°C +25°C +70°C +85°C Temperature Accuracy Crystal Aging Temp f/fO VCC = 3.3V or VBAT = 3.3V After reflow, not production tested First year 0–10 years -3 TYP 32.768 1 0.7 0.1 0.4 0.8 UNITS kHz ppm ppm ppm/V ppm MAX ±2 ±3.5 ±3.5 ±2 ±3.5 +3 °C ±1.0 ±5.0 ppm ELECTRICAL CHARACTERISTICS (VCC = 0V, VBAT = 2.3V to 5.5V, TA = TMIN to TMAX, unless otherwise noted.) (Note 2) PARAMETER SYMBOL CONDITIONS MIN TYP Active Battery Current IBATA EOSC = 0, BBSQW = 0, SCL = 400kHz (Note 5) VBAT = 3.63V VBAT = 5.5V MAX 70 150 Timekeeping Battery Current IBATT Temperature Conversion Current IBATTC Data-Retention Current IBATTDR EOSC = 0, BBSQW = 0, EN32kHz = 1, SCL = SDA = 0V or SCL = SDA = VBAT (Note 5) VBAT = 5.5V VBAT = 3.63V EOSC = 0, BBSQW = 0, SCL = SDA = 0V or SCL = SDA = VBAT EOSC = 1, SCL = SDA = 0V, +25°C VBAT = 3.63V VBAT = 5.5V 0.84 3.0 1.0 3.5 575 650 100 UNITS μA μA μA nA Maxim Integrated 3

DS3231 Extremely Accurate I2C-Integrated RTC/TCXO/Crystal AC ELECTRICAL CHARACTERISTICS (VCC = VCC(MIN) to VCC(MAX) or VBAT = VBAT(MIN) to VBAT(MAX), VBAT > VCC, TA = TMIN to TMAX, unless otherwise noted.) (Note 2) PARAMETER SYMBOL CONDITIONS SCL Clock Frequency Bus Free Time Between STOP and START Conditions Hold Time (Repeated) START Condition (Note 7) Low Period of SCL Clock High Period of SCL Clock Data Hold Time (Notes 8, 9) Data Setup Time (Note 10) START Setup Time Rise Time of Both SDA and SCL Signals (Note 11) Fall Time of Both SDA and SCL Signals (Note 11) fSCL tBUF tHD:STA tLOW tHIGH tHD:DAT tSU:DAT tSU:STA tR tF Setup Time for STOP Condition tSU:STO Capacitive Load for Each Bus Line Capacitance for SDA, SCL Pulse Width of Spikes That Must Be Suppressed by the Input Filter Pushbutton Debounce Reset Active Time Oscillator Stop Flag (OSF) Delay Temperature Conversion Time CB CI/O tSP PBDB tRST tOSF tCONV Fast mode Standard mode Fast mode Standard mode Fast mode Standard mode Fast mode Standard mode Fast mode Standard mode Fast mode Standard mode Fast mode Standard mode Fast mode Standard mode Fast mode Standard mode Fast mode Standard mode Fast mode Standard mode (Note 11) (Note 12) POWER-SWITCH CHARACTERISTICS (TA = TMIN to TMAX) MIN 100 0 1.3 4.7 0.6 4.0 1.3 4.7 0.6 4.0 0 0 100 250 0.6 4.7 20 + 0.1CB 20 + 0.1CB 0.6 4.7 TYP 10 30 250 250 100 125 MAX 400 100 UNITS kHz 0.9 0.9 300 1000 300 300 400 200 μs μs μs μs μs ns μs ns ns μs pF pF ns ms ms ms ms PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS VCC Fall Time; VPF(MAX) to VPF(MIN) VCC Rise Time; VPF(MIN) to VPF(MAX) Recovery at Power-Up tVCCF tVCCR tREC (Note 13) 300 0 250 300 μs μs ms 4 Maxim Integrated

DS3231 Extremely Accurate I2C-Integrated RTC/TCXO/Crystal Pushbutton Reset Timing RST PBDB tRST Power-Switch Timing VCC VPF(MAX) VPF(MIN) RST tVCCF VPF VPF tVCCR tREC Maxim Integrated 5

DS3231 Extremely Accurate I2C-Integrated RTC/TCXO/Crystal Data Transfer on I2C Serial Bus SDA SCL tBUF tLOW tR tF tHD:STA tSP tHD:STA tHIGH tSU:STA STOP START tSU:DAT REPEATED START tHD:DAT tSU:STO WARNING: Negative undershoots below -0.3V while the part is in battery-backed mode may cause loss of data. Note 2: Limits at -40°C are guaranteed by design and not production tested. Note 3: All voltages are referenced to ground. Note 4: Note 5: Current is the averaged input current, which includes the temperature conversion current. Note 6: The RST pin has an internal 50kΩ (nominal) pullup resistor to VCC. Note 7: After this period, the first clock pulse is generated. Note 8: A device must internally provide a hold time of at least 300ns for the SDA signal (referred to the VIH(MIN) of the SCL signal) ICCA—SCL clocking at max frequency = 400kHz. to bridge the undefined region of the falling edge of SCL. Note 9: The maximum tHD:DAT needs only to be met if the device does not stretch the low period (tLOW) of the SCL signal. Note 10: A fast-mode device can be used in a standard-mode system, but the requirement tSU:DAT ≥ 250ns must then be met. This is automatically the case if the device does not stretch the low period of the SCL signal. If such a device does stretch the low period of the SCL signal, it must output the next data bit to the SDA line tR(MAX) + tSU:DAT = 1000 + 250 = 1250ns before the SCL line is released. Note 11: CB—total capacitance of one bus line in pF. Note 12: The parameter tOSF is the period of time the oscillator must be stopped for the OSF flag to be set over the voltage range of 0.0V ≤ VCC ≤ VCC(MAX) and 2.3V ≤ VBAT ≤ 3.4V. Note 13: This delay applies only if the oscillator is enabled and running. If the EOSC bit is a 1, tREC is bypassed and RST immedi- ately goes high. The state of RST does not affect the I2C interface, RTC, or TCXO. 6 Maxim Integrated

DS3231 Extremely Accurate I2C-Integrated RTC/TCXO/Crystal Typical Operating Characteristics (VCC = +3.3V, TA = +25°C, unless otherwise noted.) ) A μ ( S C C I ) A μ ( T A B I 150 125 100 75 50 25 0 1.0 0.9 0.8 0.7 0.6 STANDBY SUPPLY CURRENT vs. SUPPLY VOLTAGE BSY = 0, SCL = SDA = VCC RST ACTIVE 1 0 c o t 1 3 2 3 S D 2.0 2.5 3.0 4.0 3.5 VCC (V) 4.5 5.0 5.5 SUPPLY CURRENT vs. TEMPERATURE VCC = 0, EN32kHz = 1, BSY = 0, SDA = SCL = VBAT OR GND 3 0 c o t 1 3 2 3 S D -40 -15 10 35 60 85 TEMPERATURE (°C) 1.2 1.1 1.0 0.9 0.8 0.7 0.6 60 50 40 30 20 10 0 -10 -20 -30 -40 SUPPLY CURRENT vs. SUPPLY VOLTAGE VCC = 0V, BSY = 0, SDA = SCL = VBAT OR VCC 2 0 c o t 1 3 2 3 S D EN32kHz = 1 EN32kHz = 0 2.3 3.3 4.3 5.3 VBAT (V) FREQUENCY DEVIATION vs. TEMPERATURE vs. AGING VALUE 4 0 c o t 1 3 2 3 S D -128 -33 0 32 127 -40 -15 10 35 60 85 TEMPERATURE (°C) ) A μ ( T A B I ) m p p ( I I N O T A V E D Y C N E U Q E R F ) m p p ( Y C N E U Q E R F A T L E D 20 0 -20 -40 -60 -80 -100 -120 -140 -160 -180 -200 DELTA TIME AND FREQUENCY vs. TEMPERATURE DS3231 toc05 CRYSTAL +20ppm TYPICAL CRYSTAL, UNCOMPENSATED CRYSTAL -20ppm DS3231 ACCURACY BAND -40 -30 -20 -10 0 10 20 30 40 TEMPERATURE (°C) 50 60 70 80 ) R A E Y / I N M ( E M I T A T L E D 0 -20 -40 -60 -80 -100 Maxim Integrated 7

DS3231 Extremely Accurate I2C-Integrated RTC/TCXO/Crystal OSCILLATOR AND CAPACITOR ARRAY X1 X2 CONTROL LOGIC/ DIVIDER SQUARE-WAVE BUFFER; INT/SQW CONTROL 1Hz VCC VBAT GND SCL SDA POWER CONTROL TEMPERATURE SENSOR ALARM, STATUS, AND CONTROL REGISTERS I2C INTERFACE AND ADDRESS REGISTER DECODE DS3231 1Hz CLOCK AND CALENDAR REGISTERS USER BUFFER (7 BYTES) VOLTAGE REFERENCE; DEBOUNCE CIRCUIT; PUSHBUTTON RESET Block Diagram 32kHz INT/SQW RST N N VCC N 8 Maxim Integrated

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