M41T00 SGS-Thomson-Microelectronics, M41T00 Datasheet
M41T00
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M41T00 Summary of contents
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... AUTOMATIC LEAP YEAR COMPENSATION SPECIAL SOFTWARE PROGRAMMABLE OUTPUT DESCRIPTION ® The M41T00 TIMEKEEPER Serial TIMEKEEPER with a built-in 32.768kHz os- cillator (external crystal controlled). Eight bytes of the RAM are used for the clock/calendar function and are configured in binary coded decimal (BCD) format. Addresses and data are transferred serial- ly via a two-line bi-directional bus ...
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... The energy needed to sustain the RAM and clock operations can be supplied from a small lithium coin cell. Typical data retention time is in excess of 5years with a 50mA/h 3V lithium cell. The M41T00 is sup- plied in 8 lead Plastic Small Outline package. 2/15 Parameter Off, Oscillator Off) ...
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... Date Date Month Years S Calibration 1 Hz SECONDS MINUTES CENTURY/HOURS DAY DATE MONTH YEAR CONTROL Function/Range BCD Format D1 D0 Seconds Minutes Century/Hour Day Day Date Month Year Control X = Don’t care CEB = Century Enable Bit CB = Century Bit M41T00 AI00603 00-59 00-59 0-1/00-23 01-07 01-31 01-12 00-99 3/15 ...
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... M41T00 Table 4. AC Measurement Conditions Input Rise and Fall Times Input Pulse Voltages Input and Output Timing Ref. Voltages Note that Output Hi-Z is defined as the point where data is no longer driven. 2-WIRE BUS CHARACTERISTICS This bus is intended for communication between different ICs. It consists of two lines: one bi-direc- tional for data signals (SDA) and one for clock sig- nals (SCL) ...
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... Load Capacitance L Note: Load capacitors are integrated within the M41T00. Circuit board layout considerations for the 32.768kHz crystal of minimum trace lengths and isolation from RF generating signals should be taken into account. STMicroelectronics recommends the KDS DT-38 Tuning Fork Type quartz crystal for industrial temperature operations. ...
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... M41T00 Table 9. Power Down/Up AC Characteristics (T = –40 to 85°C) A Symbol t SCL and SDA SCL and SDA REC Note fall time should not exceed 5mV/µs. CC Figure 5. Power Down/Up Mode AC Waveforms tPD SDA SCL Acknowledge. Each byte of eight bits is followed by one acknowledge bit ...
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... Figure 9). READ MODE In this mode, the master reads the M41T00 slave after setting the slave address (see Figure 11). Following the write mode control bit (R and the acknowledge bit, the word address An is writ- Parameter ten to the on-chip address pointer ...
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... M41T00 Figure 6. Serial Bus Data Transfer Sequence CLOCK DATA START CONDITION Figure 7. Acknowledgment Sequence START SCLK FROM MASTER DATA OUTPUT BY TRANSMITTER DATA OUTPUT BY RECEIVER CLOCK OPERATION The eight byte clock register (see Table 3) is used to both set the clock and to read the date and time from the clock binary coded decimal format ...
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... CLOCK CALIBRATION The M41T00 is driven by a quartz controlled oscil- lator with a nominal frequency of 32,768Hz. The devices are tested not to exceed 35ppm (parts per million) oscillator frequency error at 25°C, which equates to about ±1.53 minutes per month. With the calibration bits properly set, the accuracy of each M41T00 improves to better than +2/– ...
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... M41T00 Figure 10. Write Mode Sequence BUS ACTIVITY: MASTER SDA LINE S BUS ACTIVITY: SLAVE ADDRESS Figure 11. Read Mode Sequence BUS ACTIVITY: MASTER SDA LINE S BUS ACTIVITY: SLAVE ADDRESS Figure 12. Alternate Read Mode Sequence BUS ACTIVITY: MASTER SDA LINE S BUS ACTIVITY: SLAVE ADDRESS ...
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... CALIBRATION NEGATIVE CALIBRATION Two methods are available for ascertaining how much calibration a given M41T00 may require. The first involves simply setting the clock, letting it run for a month and comparing known accu- rate reference (like WWV broadcasts). While that may seem crude, it allows the designer to give the ...
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... M41T00 Figure 14. Crystal Accuracy Across Temperature Frequency (ppm –20 –40 –60 –80 –100 –120 –140 –160 –40 –30 –20 12/ -0.038 ppm ( – Temperature 10 AI00999 ...
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... TR = Tape & Reel For a list of available options (Speed, Package, etc...) or for further information on any aspect of this de- vice, please contact the ST Sales Office nearest to you. Table 12. Revision History Date March 1999 First Issue 05/15/00 AC Characteristic conditions changed (Table 10) M41T00 Revision Details M41T00 13/15 ...
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... M41T00 Table 13. SO8 - 8 lead Plastic Small Outline, 150 mils body width, Package Mechanical Data Symb Typ 1. Figure 15. SO8 - 8 lead Plastic Small Outline, 150 mils body width, Package Outline SO-a Drawing is not to scale. 14/15 mm Min Max 1 ...
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... Australia - Brazil - China - Finland - France - Germany - Hong Kong - India - Italy - Japan - Malaysia - Malta - Morocco - Singapore - Spain - Sweden - Switzerland - United Kingdom - U.S.A. The ST logo is registered trademark of STMicroelectronics © 2000 STMicroelectronics - All Rights Reserved All other names are the property of their respective owners. STMicroelectronics GROUP OF COMPANIES http://www.st.com M41T00 15/15 ...