M48T37V10MH1TR STMicroelectronics, M48T37V10MH1TR Datasheet
M48T37V10MH1TR
Specifications of M48T37V10MH1TR
Related parts for M48T37V10MH1TR
M48T37V10MH1TR Summary of contents
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V, 256 Kbit (32 Kbit x 8) TIMEKEEPER Features ■ Integrated ultra low power SRAM, real-time clock, power-fail control circuit, and battery ■ Frequency test output for real-time clock software calibration ■ Automatic power-fail chip deselect and ...
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Contents Contents 1 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...
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M48T37Y, M48T37V 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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M48T37Y, M48T37V 1 Description The M48T37Y/V TIMEKEEPER clock. The monolithic chip is available in a special package which provides a highly integrated battery-backed memory and real-time clock solution. The 44-lead, 330 mil SOIC package provides sockets with gold-plated contacts at ...
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Description Table 1. Signal names A0-A14 DQ0-DQ7 RST IRQ/FT WDI Figure 2. SOIC connections 6/30 Address inputs Data inputs / outputs Reset output (open drain) Interrupt / frequency test output (open drain) ...
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M48T37Y, M48T37V Figure 3. Block diagram 32,768 Hz CRYSTAL LITHIUM CELL IRQ/FT WDI OSCILLATOR AND CLOCK CHAIN POWER VOLTAGE SENSE V PFD AND SWITCHING CIRCUITRY V CC RST Doc ID 7019 Rev 9 Description BiPORT SRAM ARRAY ...
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Operation modes 2 Operation modes As Figure 3 on page 7 oscillator of the M48T37Y/V are integrated on one silicon chip. The memory locations that provide user accessible BYTEWIDE™ clock information are in the bytes with addresses 7FF1 and 7FF9h-7FFFh ...
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M48T37Y, M48T37V met, valid data will be available after the latter of the chip enable access time (t output enable access time (t The state of the eight three-state data I/O signals is controlled by E and G. If the ...
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Operation modes 2.2 WRITE mode The M48T37Y the WRITE mode whenever W and E are low. The start of a WRITE is referenced from the latter occurring falling edge WRITE is terminated by ...
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M48T37Y, M48T37V 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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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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M48T37Y, M48T37V Table 5. Register map Address D7 7FFFh 7FFEh 0 7FFDh 0 7FFCh 0 7FFBh 0 7FFAh 0 7FF9h ST 7FF8h W 7FF7h WDS 7FF6h AFE 7FF5h RPT4 7FF4h RPT3 7FF3h RPT2 7FF2h RPT1 7FF1h 7FF0h WDF Keys: S ...
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Clock operations 3.4 Setting the alarm clock Registers 7FF5h-7FF2h contain the alarm settings. The alarm can be configured to go off at a predetermined time on a specific day of the month or repeat every day, hour, minute, or second. ...
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M48T37Y, M48T37V Figure 8. Backup mode alarm waveforms PFD (max) V PFD (min ABE, AFE bit in Interrupt Register AF bit in Flags Register IRQ/FT 3.5 Calibrating the clock The M48T37Y/V is driven by a ...
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Clock operations Two methods are available for ascertaining how much calibration a given M48T37Y/V may require. The first involves simply setting the clock, letting it run for a month and comparing known accurate reference (like WWW broadcasts). ...
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M48T37Y, M48T37V The watchdog timer is disabled by writing a value of 00000000 to the eight bits in the watchdog register. Should the watchdog timer time out, a value of 00h needs to be written to the watchdog register in ...
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Clock operations 3.9 Battery low flag The M48T37Y/V automatically performs periodic battery voltage monitoring upon power-up. The battery low flag (BL), bit D4 of the flags register 7FF0h, will be asserted high if the ® SNAPHAT battery is found to ...
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M48T37Y, M48T37V one volt. These negative spikes can cause data corruption in the SRAM while in battery backup mode. To protect from these voltage spikes recommended to connect a Schottky diode from V 1N5817 is recommended for through ...
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Maximum ratings 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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M48T37Y, M48T37V 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 from tests ...
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DC and AC parameters Table 11. DC characteristics Symbol Parameter (2) I Input leakage current LI (3) I Output leakage current LO I Supply current CC I Supply current (standby) TTL CC1 Supply current (standby) I CC2 CMOS V Input ...
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M48T37Y, M48T37V Table 12. Power down/up AC characteristics Symbol ( PFD ( PFD PFD ( REC PFD 1. Valid for ambient operating temperature: T (except ...
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Package mechanical data 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 ...
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M48T37Y, M48T37V Figure 15. SH – 4-pin SNAPHAT Note: Drawing is not to scale. Table 15. SH – 4-pin SNAPHAT mechanical data Symbol ® housing for 48 mAh battery & ...
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Package mechanical data Figure 16. SH – 4-pin SNAPHAT Note: Drawing is not to scale. Table 16. SH – 4-pin SNAPHAT mechanical data Symbol 26/30 ® housing for 120 mAh ...
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M48T37Y, M48T37V 7 Part numbering Table 17. Ordering information scheme Example: Device type M48T Supply voltage and write protect voltage 37Y = V = 4 37V = V = 3 ...
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Environmental information 8 Environmental information Figure 17. 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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M48T37Y, M48T37V 9 Revision history Table 19. Document revision history Date Revision Dec-1999 07-Feb-2000 11-Jul-2000 19-Jun-2001 06-Aug-2001 15-Jan-2002 20-May-2002 31-Mar-2003 01-Apr-2004 08-Feb-2006 03-Aug-2007 24-Mar-2009 02-Aug-2010 1 First issue From preliminary data to datasheet; battery low flag paragraph 2 changed; 100 ...
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