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M48T512Y M48T512V*
5.0 or 3.3V, 4 Mbit (512 Kbit x 8) TIMEKEEPER(R) SRAM
FEATURES SUMMARY

INTEGRATED ULTRA LOW POWER SRAM, REAL TIME CLOCK, POWER-FAIL CONTROL CIRCUIT, BATTERY, AND CRYSTAL BCD CODED YEAR, MONTH, DAY, DATE, HOURS, MINUTES, AND SECONDS AUTOMATIC POWER-FAIL CHIP DESELECT and WRITE PROTECTION WRITE PROTECT VOLTAGES: (VPFD = Power-fail Deselect Voltage) - M48T512Y: VCC = 4.5 to 5.5V 4.2V VPFD 4.5V - M48T512V*: VCC = 3.0 to 3.6V 2.7V VPFD 3.0V CONVENTIONAL SRAM OPERATION; UNLIMITED WRITE CYCLES SOFTWARE CONTROLLED CLOCK CALIBRATION FOR HIGH ACCURACY APPLICATIONS 10 YEARS OF DATA RETENTION AND CLOCK OPERATION IN THE ABSENCE OF POWER PIN AND FUNCTION COMPATIBLE WITH INDUSTRY STANDARD 512K x 8 SRAMS SELF-CONTAINED BATTERY AND CRYSTAL IN DIP PACKAGE
Figure 1. 32-pin, PMDIP Module
32 1
PMDIP32 (PM) Module
* Contact local ST sales office for availability of 3.3V version.
February 2005 1/21
M48T512Y, M48T512V*
TABLE OF CONTENTS
FEATURES SUMMARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Figure 1. 32-pin, PMDIP Module. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 SUMMARY DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Figure 2. Table 1. Figure 3. Figure 4. Logic Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Signal Names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 32-pin DIP Connections. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
OPERATING MODES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Table 2. Operating Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 READ Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Figure 5. READ Mode AC Waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Table 3. READ Mode AC Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 WRITE Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Figure 6. WRITE AC Waveforms, WRITE Enable Controlled . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Figure 7. WRITE AC Waveforms, Chip Enable Controlled . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Table 4. WRITE Mode AC Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Data Retention Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 CLOCK OPERATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Reading the Clock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Setting the Clock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Stopping and Starting the Oscillator. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Table 5. Register Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Calibrating the Clock. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Figure 8. Crystal Accuracy Across Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Figure 9. Calibration Waveform . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 VCC Noise And Negative Going Transients. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Figure 10.Supply Voltage Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 MAXIMUM RATING. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Table 6. Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 DC AND AC PARAMETERS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Table 7. Operating and AC Measurement Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Figure 11.AC Measurement Load Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Table 8. Capacitance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Table 9. DC Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Figure 12.Power Down/Up Mode AC Waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Table 10. Power Down/Up AC Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Table 11. Power Down/Up Trip Points DC Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
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M48T512Y, M48T512V*
PACKAGE MECHANICAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Figure 13.PMDIP32 - 32-pin Plastic Module DIP, Package Outline . . . . . . . . . . . . . . . . . . . . . . . . 18 Table 12. PMDIP32 - 32-pin Plastic Module DIP, Package Mechanical Data . . . . . . . . . . . . . . . . 18 PART NUMBERING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Table 13. Ordering Information Scheme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 REVISION HISTORY. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 Table 14. Document Revision History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
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M48T512Y, M48T512V*
SUMMARY DESCRIPTION
The M48T512Y/V TIMEKEEPER(R) RAM is a 512Kb x 8 non-volatile static RAM and real time clock organized as 524,288 words by 8 bits. The special DIP package provides a fully integrated battery back-up memory and real time clock solution. The M48T512Y/V directly replaces industry standard 512Kb x 8 SRAMs. It also provides the nonvolatility of Flash without any requirement for special WRITE timing or limitations on the number of WRITEs that can be performed.
Figure 2. Logic Diagram
VCC
Table 1. Signal Names
A0-A18 DQ0-DQ7 Address Inputs Data Inputs / Outputs Chip Enable Input Output Enable Input WRITE Enable Input Supply Voltage Ground
19 A0-A18 W E G M48T512Y M48T512V
8 DQ0-DQ7
E G W VCC VSS
VSS
AI02262
Figure 3. 32-pin DIP Connections
A18 A16 A14 A12 A7 A6 A5 A4 A3 A2 A1 A0 DQ0 DQ1 DQ2 VSS 1 32 2 31 3 30 4 29 28 5 27 6 7 26 8 M48T512Y 25 9 M48T512V 24 10 23 11 22 12 21 13 20 14 19 15 18 16 17
AI02263
VCC A15 A17 W A13 A8 A9 A11 G A10 E DQ7 DQ6 DQ5 DQ4 DQ3
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M48T512Y, M48T512V*
Figure 4. Block Diagram
OSCILLATOR AND CLOCK CHAIN 32,768 Hz CRYSTAL POWER
8x8 TIMEKEEPER REGISTERS A0-A18
524,280 x 8 SRAM ARRAY LITHIUM CELL VOLTAGE SENSE AND SWITCHING CIRCUITRY VPFD
DQ0-DQ7
E W G
VCC
VSS
AI02384
5/21
M48T512Y, M48T512V*
OPERATING MODES
The 32-pin, 600mil DIP Hybrid houses a controller chip, SRAM, quartz crystal, and a long life lithium button cell in a single package. Figure 11., page 15 illustrates the static memory array and the quartz controlled clock oscillator. The clock locations contain the year, month, date, day, hour, minute, and second in 24 hour BCD format. Corrections for 28, 29 (leap year - compliant until the year 2100), 30, and 31 day months are made automatically. Byte 7FFF8h is the clock control register (see Table 5., page 11). This byte controls user access to the clock information and also stores the clock calibration setting. The seven clock bytes (7FFFFh-7FFF9h) are not the actual clock counters, they are memory locations consisting of BiPORTTM READ/WRITE memory cells Table 2. Operating Modes
Mode Deselect WRITE READ READ Deselect Deselect VSO to VPFD (min)(1) VSO(1) 4.5 to 5.5V or 3.0 to 3.6V VCC E VIH VIL VIL VIL X X G X X VIL VIH X X W X VIL VIH VIH X X DQ0-DQ7 High Z DIN DOUT High Z High Z High Z Power Standby Active Active Active CMOS Standby Battery Back-up Mode
within the static RAM array. The M48T512Y/V includes a clock control circuit which updates the clock bytes with current information once per second. The information can be accessed by the user in the same manner as any other location in the static memory array. The M48T512Y/V also has its own Power-Fail Detect circuit. This control circuitry constantly monitors the supply voltage for an out of tolerance condition. When VCC is out of tolerance, the circuit write protects the TIMEKEEPER register data and SRAM, providing data security in the midst of unpredictable system operation. As VCC falls, the control circuitry automatically switches to the battery, maintaining data and clock operation until valid power is restored.
Note: X = VIH or VIL; VSO = Battery Back-up Switchover Voltage. 1. See Table 10., page 17 for details.
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M48T512Y, M48T512V*
READ Mode The M48T512Y/V is in the READ Mode whenever W (WRITE Enable) is high and E (Chip Enable) is low. The unique address specified by the 19 Address Inputs defines which one of the 524,288 bytes of data is to be accessed. Valid data will be available at the Data I/O pins within Address Access Time (tAVQV) after the last address input signal is stable, providing the E and G access times are also satisfied. If the E and G access times are not met, valid data will be available after the latter Figure 5. READ Mode AC Waveforms
tAVAV A0-A18 tAVQV tELQV E tELQX tGLQV G tGLQX DQ0-DQ7 DATA OUT
AI02389
of the Chip Enable Access Times (tELQV) or Output Enable Access Time (tGLQV). The state of the eight three-state Data I/O signals is controlled by E and G. If the outputs are activated before tAVQV, the data lines will be driven to an indeterminate state until tAVQV. If the Address Inputs are changed while E and G remain active, output data will remain valid for Output Data Hold Time (tAXQX) but will go indeterminate until the next Address Access.
VALID tAXQX tEHQZ
tGHQZ
Note: WE = High.
Table 3. READ Mode AC Characteristics
M48T512Y Symbol Parameter(1) Min tAVAV tAVQV tELQV tGLQV tELQX(2) tGLQX(2) tEHQZ(2) tGHQZ(2) tAXQX READ Cycle Time Address Valid to Output Valid Chip Enable Low to Output Valid Output Enable Low to Output Valid Chip Enable Low to Output Transition Output Enable Low to Output Transition Chip Enable High to Output Hi-Z Output Enable High to Output Hi-Z Address Transition to Output Transition 10 5 5 25 25 5 70 70 70 40 5 5 30 30 -70 Max Min 85 85 85 55 M48T512V -85 Max ns ns ns ns ns ns ns ns ns Unit
Note: 1. Valid for Ambient Operating Temperature: TA = 0 to 70C; VCC = 4.5 to 5.5V or 3.0 to 3.6V (except where noted). 2. CL = 5pF.
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M48T512Y, M48T512V*
WRITE Mode The M48T512Y/V is in the WRITE Mode whenever W (WRITE Enable) and E (Chip Enable) are low state after the address inputs are stable. The start of a WRITE is referenced from the latter occurring falling edge of W or E. A WRITE is terminated by the earlier rising edge of W or E. The addresses must be held valid throughout the cycle. E or W must return high for a minimum of tEHAX from Chip Enable or tWHAX from WRITE Enable prior to the initiation of another READ or WRITE cycle. Data-in must be valid tDVWH prior to the end of WRITE and remain valid for tWHDX afterward. G should be kept high during WRITE cycles to avoid bus contention; although, if the output bus has been activated by a low on E and G a low on W will disable the outputs tWLQZ after W falls.
Figure 6. WRITE AC Waveforms, WRITE Enable Controlled
tAVAV A0-A18 VALID tAVWH tAVEL E tWLWH tAVWL W tWLQZ tWHDX DQ0-DQ7 DATA INPUT tDVWH
AI02386
tWHAX
tWHQX
Figure 7. WRITE AC Waveforms, Chip Enable Controlled
tAVAV A0-A18 VALID tAVEH tAVEL E tAVWL W tEHDX DQ0-DQ7 DATA INPUT tDVEH
AI02387
tELEH
tEHAX
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M48T512Y, M48T512V*
Table 4. WRITE Mode AC Characteristics
M48T512Y Symbol Parameter
(1)
M48T512V -85 Unit Max ns ns ns ns ns ns ns ns ns ns ns 30 70 70 5 ns ns ns ns
-70 Min Max Min 85 0 0 60 65 5 15 35 35 5 15 25 60 60 5
tAVAV tAVWL tAVEL tWLWH tELEH tWHAX tEHAX tDVWH tDVEH tWHDX tEHDX tWLQZ (2,3) tAVWH tAVEH tWHQX (2,3)
WRITE Cycle Time Address Valid to WRITE Enable Low Address Valid to Chip Enable Low WRITE Enable Pulse Width Chip Enable Low to Chip Enable High WRITE Enable High to Address Transition Chip Enable High to Address Transition Input Valid to WRITE Enable High Input Valid to Chip Enable High WRITE Enable High to Input Transition Chip Enable High to Input Transition WRITE Enable Low to Output Hi-Z Address Valid to WRITE Enable High Address Valid to Chip Enable High WRITE Enable High to Output Transition
70 0 0 50 55 5 10 30 30 5 10
Note: 1. Valid for Ambient Operating Temperature: TA = 0 to 70C; VCC = 4.5 to 5.5V or 3.0 to 3.6V (except where noted). 2. CL = 5pF. 3. If E goes low simultaneously with W going low, the outputs remain in the high impedance state.
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M48T512Y, M48T512V*
Data Retention Mode With valid VCC applied, the M48T512Y/V operates as a conventional BYTEWIDETM static RAM. Should the supply voltage decay, the RAM will automatically deselect, write protecting itself when VCC falls between VPFD (max), VPFD (min) window. All outputs become high impedance and all inputs are treated as "Don't care." Note: A power failure during a WRITE cycle may corrupt data at the current addressed location, but does not jeopardize the rest of the RAM's content. At voltages below VPFD (min), the memory will be in a write protected state, provided the VCC fall time is not less than tF. The M48T512Y/V may respond to transient noise spikes on VCC that cross into the deselect window during the time the device is sampling VCC.Therefore, decoupling of the power supply lines is recommended. When VCC drops below VSO, the control circuit switches power to the internal battery, preserving data and powering the clock. The internal energy source will maintain data in the M48T512Y/V for an accumulated period of at least 10 years at room temperature. As system power rises above VSO, the battery is disconnected, and the power supply is switched to external VCC. Write protection continues until VCC reaches VPFD (min) plus tREC (min). Normal RAM operation can resume tREC after VCC exceeds VPFD (max). Refer to Application Note (AN1012) on the ST Web Site for more information on battery life.
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M48T512Y, M48T512V*
CLOCK OPERATIONS
Reading the Clock Updates to the TIMEKEEPER(R) registers should be halted before clock data is read to prevent reading data in transition (see Table 5.). The BiPORTTM TIMEKEEPER cells in the RAM array are only data registers and not the actual clock counters, so updating the registers can be halted without disturbing the clock itself. Updating is halted when a '1' is written to the READ Bit, D6 in the Control Register (7FFF8h). As long as a '1' remains in that position, updating is halted. After a halt is issued, the registers reflect the count; that is, the day, date, and time that were current at the moment the halt command was issued. All of the TIMEKEEPER registers are updated simultaneously. A halt will not interrupt an update in progress. Updating occurs 1 second after the READ Bit is reset to a '0.' Setting the Clock Bit D7 of the Control Register (7FFF8h) is the WRITE Bit. Setting the WRITE Bit to a '1,' like the READ Bit, halts updates to the TIMEKEEPER registers. The user can then load them with the correct day, date, and time data in 24 hour BCD format (see Table 5., page 11). Resetting the Table 5. Register Map
Data Address D7 7FFFFh 7FFFEh 7FFFDh 7FFFCh 7FFFBh 7FFFAh 7FFF9h 7FFF8h 0 0 0 0 0 ST W R D6 D5 D4 D3 D2 Year 10 M Month Date 0 0 Day Hours Minutes Seconds Calibration D1 D0 10 Years 0 0 0 0 0 Function/Range BCD Format Year Month Date Day Hours Minutes Seconds Control 00-99 01-12 01-31 01-07 00-23 00-59 00-59
WRITE Bit to a '0' then transfers the values of all time registers 7FFFFh-7FFF9h to the actual TIMEKEEPER counters and allows normal operation to resume. After the WRITE Bit is reset, the next clock update will occur approximately one second later. See Application Note, AN923, "TIMEKEEPER (R) Rolling Into the 21st Century" on the ST Web Site for more information on Century Rollover. Note: Upon power-up, both the WRITE Bit and the READ Bit will be reset to '0.' Stopping and Starting the Oscillator. The oscillator may be stopped at any time. If the device is going to spend a significant amount of time on the shelf, the oscillator can be turned off to minimize current drain on the battery. The STOP bit is located at Bit D7 within 7FFF9h. Setting it to a '1' stops the oscillator. The M48T512Y/V is shipped from STMicroelectronics with the STOP bit set to a '1.' When reset to a '0,' the M48T512Y/ V oscillator starts after approximately one second. Note: It is not necessary to set the WRITE Bit when setting or resetting the FREQUENCY TEST Bit (FT) or the STOP Bit (ST).
10 Date 0
10 Hours 10 Minutes 10 Seconds S
Keys: S = SIGN Bit R = READ Bit W = WRITE Bit ST = STOP Bit 0 = Must be set to '0'
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M48T512Y, M48T512V*
Calibrating the Clock The M48T512Y/V is driven by a quartz controlled oscillator with a nominal frequency of 32,768Hz. The devices are factory calibrated at 25C and tested for accuracy. Clock accuracy will not exceed 35 ppm (parts per million) oscillator frequency error at 25C, which equates to about 1.53 minutes per month. When the Calibration circuit is properly employed, accuracy improves to better than +1/-2 ppm at 25C. The oscillation rate of crystals changes with temperature. The M48T512Y/V design employs periodic counter correction. The calibration circuit adds or subtracts counts from the oscillator divider circuit at the divide by 256 stage (see Figure 9., page 13). The number of times pulses are blanked (subtracted, negative calibration) or split (added, positive calibration) depends upon the value loaded into the five Calibration bits found in the Control Register. Adding counts speeds the clock up, subtracting counts slows the clock down. The Calibration bits occupy the five lower order bits (D4-D0) in the Control Register 7FFF8h. These bits can be set to represent any value between 0 and 31 in binary form. Bit D5 is a Sign bit; '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 cycles. If a binary '1' is loaded into the register, only the first 2 minutes in the 64 Figure 8. Crystal Accuracy Across Temperature
Frequency (ppm) 20 0 -20 -40 -60 -80 -100 -120 -140 -160 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 F = -0.038 ppm (T - T )2 10% 0 F C2 T0 = 25 C
minute cycle will be modified; if a binary 6 is loaded, the first 12 will be affected, and so on. Therefore, each calibration step has the effect of adding 512 or subtracting 256 oscillator cycles for every 125, 829, 120 actual oscillator cycles; that is, +4.068 or -2.034 ppm of adjustment per calibration step in the calibration register. Assuming that the oscillator is running at exactly 32,768Hz, each of the 31 increments in the Calibration byte would represent +10.7 or -5.35 seconds per month which corresponds to a total range of +5.5 or -2.75 minutes per month. One method for ascertaining how much calibration a given M48T512Y/V may require involves setting the clock, letting it run for a month and comparing it to a known accurate reference and recording deviation over a fixed period of time. Calibration values, including the number of seconds lost or gained in a given period, can be found in STMicroelectronics Application Note AN934, TIMEKEEPER Calibration." This allows the designer to give the end user the ability to calibrate the clock as the environment requires, even if the final product is packaged in a non-user serviceable enclosure. The designer could provide a simple utility that accesses the Calibration bits. For more information on calibration (see the Application Note AN934, "TIMEKEEPER(R) Calibration" on the ST Web Site).
Temperature C
AI00999
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M48T512Y, M48T512V*
Figure 9. Calibration Waveform
NORMAL
POSITIVE CALIBRATION
NEGATIVE CALIBRATION
AI00594B
VCC Noise And Negative Going Transients ICC transients, including those produced by output switching, can produce voltage fluctuations, resulting in spikes on the VCC bus. These transients can be reduced if capacitors are used to store energy, which stabilizes the VCC bus. The energy stored in the bypass capacitors will be released as low going spikes are generated or energy will be absorbed when overshoots occur. A ceramic bypass capacitor value of 0.1F is recommended in order to provide the needed filtering. In addition to transients that are caused by normal SRAM operation, power cycling can generate negative voltage spikes on VCC that drive it to values below VSS by as much as one volt. These negative spikes can cause data corruption in the SRAM while in battery backup mode. To protect from these voltage spikes, ST recommends connecting a schottky diode from VCC to VSS (cathode connected to VCC, anode to VSS). (Schottky diode 1N5817 is recommended for through hole and MBRS120T3 is recommended for surface mount).
Figure 10. Supply Voltage Protection
VCC VCC
0.1F
DEVICE
VSS
AI02169
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M48T512Y, M48T512V*
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 those indicated in the Operating sections of this specification is Table 6. Absolute Maximum Ratings
Symbol TA TSTG TSLD(1) VIO VCC IO PD Parameter Ambient Operating Temperature Storage Temperature (VCC Off, Oscillator Off) Lead Solder Temperature for 10 seconds Input or Output Voltages M48T512Y Supply Voltage M48T512V Output Current Power Dissipation -0.3 to 4.6 20 1 V mA W Value 0 to 70 -40 to 85 260 -0.3 to VCC +0.3 -0.3 to 7.0 Unit C C C V V
not implied. Exposure to Absolute Maximum Rating conditions for extended periods may affect device reliability. Refer also to the STMicroelectronics SURE Program and other relevant quality documents.
Note: 1. Soldering temperature not to exceed 260C for 10 seconds (total thermal budget not to exceed 150C for longer than 30 seconds). No preheat above 150C, or direct exposure to IR reflow (or IR preheat) allowed, to avoid damaging the Lithium battery.
CAUTION: Negative undershoots below -0.3V are not allowed on any pin while in the Battery Back-up mode.
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M48T512Y, M48T512V*
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 performed under the Measurement Conditions listed in the relevant tables. Designers should check that the operating conditions in their projects match the measurement conditions when using the quoted parameters.
Table 7. Operating and AC Measurement Conditions
Parameter Supply Voltage (VCC) Ambient Operating Temperature (TA) Load Capacitance (CL) Input Rise and Fall Times Input Pulse Voltages Input and Output Timing Ref. Voltages M48T512Y 4.5 to 5.5 0 to 70 100 5 0 to 3 1.5 M48T512V 3.0 to 3.6 0 to 70 50 5 0 to 3 1.5 Unit V C pF ns V V
Figure 11. AC Measurement Load Circuit
DEVICE UNDER TEST
650
CL
1.75V
CL includes JIG capacitance
AI03971
Note: 50pF for M48T512V.
Table 8. Capacitance
Symbol CIN CIO(3) Input Capacitance Input / Output Capacitance Parameter(1,2) Min Max 20 20 Unit pF pF
Note: 1. Effective capacitance measured with power supply at 5V (M48T512Y) or 3.3V (M48T512V). Sampled only, not 100% tested. 2. At 25C, f = 1MHz. 3. Outputs deselected.
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M48T512Y, M48T512V*
Table 9. DC Characteristics
M48T512Y Symbol Parameter Test Condition(1) Min ILI ILO(2) ICC ICC1 ICC2 VIL VIH VOL VOH Input Leakage Current Output Leakage Current Supply Current Supply Current (Standby) TTL Supply Current (Standby) CMOS Input Low Voltage Input High Voltage Output Low Voltage Output High Voltage IOL = 2.1mA IOH = -1mA 2.4 0V VIN VCC 0V VOUT VCC Outputs open E = VIH E = VCC - 0.2V -0.3 2.2 -70 Max 2 2 115 8 4 0.8 VCC +0.3 0.4 2.2 -0.3 2.2 Min M48T512V -85 Max 2 2 60 4 3 0.4 VCC +0.3 0.4 A A mA mA mA V V V V Unit
Note: 1. Valid for Ambient Operating Temperature: TA = 0 to 70C; VCC = 4.5 to 5.5V or 3.0 to 3.6V (except where noted). 2. Outputs deselected.
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M48T512Y, M48T512V*
Figure 12. Power Down/Up Mode AC Waveforms
VCC VPFD (max) VPFD (min) VSO VSS
tF tFB
tDR tRB DON'T CARE
tR tREC
RECOGNIZED
INPUTS
(Including E)
RECOGNIZED
HIGH-Z OUTPUTS VALID VALID
AI02385
Table 10. Power Down/Up AC Characteristics
Symbol tF(2) tFB(3) tR tRB tREC Parameter(1) VPFD (max) to VPFD (min) VCC Fall Time M48T512Y VPFD (min) to VSS VCC Fall Time VPFD (min) to VPFD (max) VCC Rise Time VSS to VPFD (min) VCC Rise Time E Recovery Time M48T512V Min 300 10 150 10 1 40 200 Max Unit s s s s s ms
Note: 1. Valid for Ambient Operating Temperature: TA = 0 to 70C; VCC = 4.5 to 5.5V or 3.0 to 3.6V (except where noted). 2. VPFD (max) to VPFD (min) fall time of less than tF may result in deselection/write protection not occurring until 200s after VCC passes VPFD (min). 3. VPFD (min) to VSS fall time of less than tFB may cause corruption of RAM data.
Table 11. Power Down/Up Trip Points DC Characteristics
Symbol VPFD Parameter(1,2) M48T512Y Power-fail Deselect Voltage M48T512V M48T512Y VSO tDR(3) Battery Back-up Switchover Voltage M48T512V Expected Data Retention Time 10 VPFD -100mV V YEARS 2.7 2.9 3.0 3.0 V V Min 4.2 Typ 4.35 Max 4.5 Unit V
Note: 1. All voltages referenced to VSS. 2. Valid for Ambient Operating Temperature: TA = 0 to 70C; VCC = 4.5 to 5.5V or 3.0 to 3.6V (except where noted). 3. At 25C, VCC = 0V.
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M48T512Y, M48T512V*
PACKAGE MECHANICAL INFORMATION
Figure 13. PMDIP32 - 32-pin Plastic Module DIP, Package Outline
A
A1 S B e3 D e1
L eA
C
N
E
1 PMDIP
Note: Drawing is not to scale.
Table 12. PMDIP32 - 32-pin Plastic Module DIP, Package Mechanical Data
mm Symb Typ A A1 B C D E e1 e3 eA L S N Min 9.27 0.38 0.43 0.20 42.42 18.03 2.29 34.29 14.99 3.05 1.91 32 Max 9.52 - 0.59 0.33 43.18 18.80 2.79 41.91 16.00 3.81 2.79 Typ Min 0.365 0.015 0.017 0.008 1.670 0.710 0.090 1.350 0.590 0.120 0.075 32 Max 0.375 - 0.023 0.013 1.700 0.740 0.110 1.650 0.630 0.150 0.110 inches
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M48T512Y, M48T512V*
PART NUMBERING
Table 13. Ordering Information Scheme
Example: M48T 512Y -70 PM 1
Device Type M48T
Supply Voltage and Write Protect Voltage 512Y = VCC = 4.5 to 5.5V; VPFD = 4.2 to 4.5V 512V(1) = VCC = 3.0 to 3.6V; VPFD = 2.7 to 3.0V
Speed -70 = 70ns (512Y) -85 = 85ns (512V)
Package PM = PMDIP32
Temperature Range 1 = 0 to 70C
Note: 1. Contact local ST sales office for availability of 3.3V version.
For other options, or for more information on any aspect of this device, please contact the ST Sales Office nearest you.
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M48T512Y, M48T512V*
REVISION HISTORY
Table 14. Document Revision History
Date June 1998 03-Dec-99 11-Dec-00 20-Jul-01 07-Aug-01 20-May-02 07-Aug-02 31-Mar-03 22-Feb-05 Version 1.0 1.1 2.0 2.1 2.2 2.3 2.4 3.0 4.0 First Issue M48T512Y: VPFD (Min) changed; AC Measurement Load Circuit changed (Figure 11); tFB and tRB changed (Figure 12, Table 10) Reformatted Segments re-ordered; temp./voltage info. added to tables (Table 8, 9, 3, 4, 10, 11) Text re-ordered from last adjustment ("Operating Modes" section) Add countries to disclaimer Add marketing status v2.2 template applied; data retention condition updated (Table 11) Reformatted; IR reflow update (Table 6) Revision Details
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M48T512Y, M48T512V*
Information furnished is believed to be accurate and reliable. However, STMicroelectronics assumes no responsibility for the consequences of use of such information nor for any infringement of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of STMicroelectronics. Specifications mentioned in this publication are subject to change without notice. This publication supersedes and replaces all information previously supplied. STMicroelectronics products are not authorized for use as critical components in life support devices or systems without express written approval of STMicroelectronics. The ST logo is a registered trademark of STMicroelectronics. All other names are the property of their respective owners (c) 2005 STMicroelectronics - All rights reserved STMicroelectronics group of companies Australia - Belgium - Brazil - Canada - China - Czech Republic - Finland - France - Germany - Hong Kong - India - Israel - Italy - Japan Malaysia - Malta - Morocco - Singapore - Spain - Sweden - Switzerland - United Kingdom - United States of America www.st.com
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