M41T80M ST Microelectronics, M41T80M Datasheet
M41T80M
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M41T80M Summary of contents
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FEATURES SUMMARY 2.0 TO 5.5V CLOCK OPERATING VOLTAGE COUNTERS FOR TENTHS/HUNDREDTHS OF SECONDS, SECONDS, MINUTES, HOURS, DAY, DATE, MONTH, YEAR, and CENTURY SERIAL INTERFACE SUPPORTS I (400KHz) PROGRAMMABLE ALARM and INTERRUPT FUNCTION LOW OPERATING CURRENT OF 200µA OPERATING TEMPERATURE OF ...
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M41T80 TABLE OF CONTENTS SUMMARY DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...
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SUMMARY DESCRIPTION The M41T80 Serial Access TIMEKEEPER SRAM is a low power Serial RTC with a built-in 32.768 KHz oscillator (external crystal controlled). Eight registers (see Table 8, page 13) are used for the clock/calendar function and are configured in ...
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M41T80 MAXIMUM RATING Stressing the device above the rating listed in the “Absolute Maximum Ratings” table may cause permanent damage to the device. These are stress ratings only and operation of the device at these or any other conditions above ...
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DC AND AC PARAMETERS This section summarizes the operating and mea- surement conditions, as well as the DC and AC characteristics of the device. The parameters in the following DC and AC Characteristic tables are derived from tests performed under ...
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M41T80 Table 5. DC Characteristics Symbol Parameter Input Leakage I LI Current Output Leakage I LO Current I Supply Current CC1 Supply Current (2) I CC2 (standby) Switch Freq (SCL) = 0Hz V Input Low Voltage IL V Input High ...
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OPERATION The M41T80 clock operates as a slave device on the serial bus. Access is obtained by implementing a start condition followed by the correct slave ad- dress (D0h). The 20 bytes contained in the device can then be accessed ...
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M41T80 Figure 6. Serial Bus Data Transfer Sequence CLOCK DATA START CONDITION Figure 7. Acknowledgement Sequence START SCL FROM MASTER DATA OUTPUT BY TRANSMITTER DATA OUTPUT BY RECEIVER 8/20 DATA LINE STABLE DATA VALID CHANGE OF DATA ALLOWED 1 2 ...
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Figure 8. Bus Timing Requirements Sequence SDA tBUF SCL P S Table 7. AC Characteristics Sym f SCL Clock Frequency SCL t Clock Low Period LOW t Clock High Period HIGH t SDA and SCL Rise Time R t SDA ...
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M41T80 READ Mode In this mode the master reads the M41T80 slave after setting the slave address (see Figure 10, page 10). Following the WRITE Mode Control Bit (R/W=0) and the Acknowledge Bit, the word ad- dress 'An' is written ...
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Figure 11. Alternative READ Mode Sequence BUS ACTIVITY: MASTER SDA LINE S BUS ACTIVITY: SLAVE ADDRESS WRITE Mode In this mode the master transmitter transmits to the M41T80 slave receiver. Bus protocol is shown in Figure 12, page 11. Following ...
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M41T80 CLOCK OPERATION The M41T80 is driven by a quartz-controlled oscil- lator with a nominal frequency of 32,768Hz. The accuracy of the Real Time Clock depends on the frequency of the quartz crystal that is used as the time-base for ...
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Table 8. TIMEKEEPER Register Map Addr 00h 0.1 Seconds 01h ST 10 Seconds 02h 0 10 Minutes 03h CEB CB 04h 0 0 05h 0 0 06h 0 0 07h 10 Years 08h OUT 0 09h ...
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M41T80 Setting Alarm Clock Registers Address locations 0Ah-0Eh contain the alarm set- tings. The alarm can be configured to go off at a prescribed time on a specific month, date, hour, minute, or second or repeat every year, month, day, ...
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Table 10. Square Wave Output Frequency Square Wave Bits RS3 RS2 ...
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M41T80 Century Bit Bits D7 and D6 of Clock Register 03h contain the CENTURY ENABLE Bit (CEB) and the CENTURY Bit (CB). Setting CEB to a '1' will cause CB to tog- gle, either from a '0' to '1' or ...
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PART NUMBERING Table 12. Ordering Information Scheme Example: Device Type M41T Supply Voltage and Write Protect Voltage 2.0 to 5.5V CC Package M = SO8 Temperature Range 6 = –40°C to 85°C Shipping Method for SOIC ...
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M41T80 PACKAGE MECHANICAL INFORMATION Figure 14. SO8 – 8 lead Plastic Small Outline, 150 mils body width, Package Mechanical Drawing Note: Drawing is not to scale. Table 13. SO8 – 8-lead Plastic Small Outline, ...
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REVISION HISTORY Table 14. Document Revision History Date Rev. # October 2002 1.0 First Issue Revision Details M41T80 19/20 ...
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M41T80 M41T80, 41T80, T80, Serial, Serial, Serial, Serial, Serial, Serial, Serial, Serial, Serial, Serial, Serial, Serial, Serial, Serial, Serial, Serial, Serial, Serial, Serial, Serial, Serial, Serial, Serial, Serial, Serial, Serial, Serial, Serial, Serial, Serial, Serial, Serial, Serial, Serial, Serial, Serial, ...