M48T02_10 STMICROELECTRONICS [STMicroelectronics], M48T02_10 Datasheet
M48T02_10
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M48T02_10 Summary of contents
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Features ■ Integrated, ultra low power SRAM, real-time clock, and power-fail control circuit ™ ■ BYTEWIDE RAM-like clock access ■ BCD coded year, month, day, date, hours, minutes, and seconds ■ Typical clock accuracy of ±1 minute a month, at ...
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Contents Contents 1 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...
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M48T02, M48T12 List of tables Table 1. Signal names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...
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List of figures List of figures Figure 1. Logic diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...
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M48T02, M48T12 1 Description The M48T02/12 TIMEKEEPER clock which is pin and functional compatible with the DS1642. A special 24-pin, 600 mil DIP CAPHAT quartz crystal and a long life lithium button cell to form a highly integrated battery-backed memory ...
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Description Figure 2. DIP connections Figure 3. Block diagram 32,768 Hz CRYSTAL LITHIUM CELL 6/ M48T02 19 M48T12 ...
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M48T02, M48T12 2 Operation modes As Figure 3 on page 6 oscillator of the M48T02/12 are integrated on one silicon chip. The two circuits are interconnected at the upper eight memory locations to provide user accessible BYTEWIDE™ clock information in ...
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Operation modes The state of the eight three-state data I/O signals is controlled by E and G. If the outputs are activated before t the address inputs are changed while E and G remain active, output data will remain valid ...
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M48T02, M48T12 2.2 WRITE mode The M48T02/ the WRITE mode whenever W and E are active. The start of a WRITE is referenced from the latter occurring falling edge WRITE is terminated by ...
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Operation modes Table 4. WRITE mode AC characteristics Symbol t WRITE cycle time AVAV t Address valid to WRITE enable low AVWL t Address valid to chip enable low AVEL t WRITE enable pulse width WLWH t Chip enable low ...
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M48T02, M48T12 Figure 7. Checking the BOK flag status POWER-UP READ DATA AT ANY ADDRESS WRITE DATA COMPLEMENT BACK TO SAME ADDRESS READ DATA AT SAME ADDRESS AGAIN IS DATA NO (BATTERY LOW) COMPLEMENT OF FIRST READ? NOTIFY SYSTEM (BATTERY ...
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Clock operations 3 Clock operations 3.1 Reading the clock Updates to the TIMEKEEPER prevent reading data in transition. The BiPORT™ TIMEKEEPER cells in the RAM array are only data registers and not the actual clock counters, so updating the registers ...
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M48T02, M48T12 Table 5. Register map Address D7 7FF 7FE 0 7FD 0 7FC 0 7FB 0 7FA 0 7F9 ST 7F8 W Keys SIGN bit FT = FREQUENCY TEST bit (set to '0' for normal clock operation) ...
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Clock operations '1' indicates positive calibration, '0' indicates negative calibration. Calibration occurs within a 64 minute cycle. The first 62 minutes in the cycle may, once per minute, have one second either shortened by 128 or lengthened by 256 oscillator ...
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M48T02, M48T12 Figure 8. Crystal accuracy across temperature ppm 20 0 -20 -40 ΔF = -0.038 -60 -80 -100 Figure 9. Clock calibration NORMAL POSITIVE CALIBRATION NEGATIVE CALIBRATION ppm 2 ± 10 ...
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Clock operations 3.5 V noise and negative going transients CC I transients, including those produced by output switching, can produce voltage CC fluctuations, resulting in spikes on the V capacitors are used to store energy which stabilizes the V bypass ...
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M48T02, M48T12 4 Maximum ratings 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 ...
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DC and AC parameters 5 DC and AC parameters This section summarizes the operating and measurement conditions, as well as the DC and AC characteristics of the device. The parameters in the following DC and AC characteristic tables are derived ...
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M48T02, M48T12 Table 9. DC characteristics Symbol Parameter I Input leakage current LI (2) I Output leakage current LO I Supply current CC (3) I Supply current (standby) TTL CC1 (3) I Supply current (standby) CMOS CC2 V Input low ...
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DC and AC parameters Table 10. Power down/up AC characteristics Symbol ( PFD ( PFD PFD ...
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M48T02, M48T12 6 Package mechanical data In order to meet environmental requirements, ST offers these devices in different grades of ® ECOPACK packages, depending on their level of environmental compliance. ECOPACK specifications, grade definitions and product status are available at: ...
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Part numbering 7 Part numbering Table 13. Ordering information scheme Example: Device type M48T Supply voltage and write protect voltage 4. 4 ...
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M48T02, M48T12 8 Environmental information Figure 14. Recycling symbols This product contains a non-rechargeable lithium (lithium carbon monofluoride chemistry) button cell battery fully encapsulated in the final product. Recycle or dispose of batteries in accordance with the battery manufacturer's instructions ...
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Revision history 9 Revision history Table 14. Document revision history Date Revision Jul-2000 13-Jul-2000 07-May-2001 14-May-2001 16-Jul-2001 20-May-2002 26-Jun-2002 28-Mar-2003 31-Mar-2004 12-Dec-2005 21-Sep-2007 13-Jan-2009 02-Aug-2010 24/25 1.0 First issue 1.1 t change (Table 10) rec 2.0 Reformatted; temp. / voltage ...
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M48T02, M48T12 Information in this document is provided solely in connection with ST products. STMicroelectronics NV and its subsidiaries (“ST”) reserve the right to make changes, corrections, modifications or improvements, to this document, and the products and services described herein ...