STMICROELECTRONICS M48T128Y_10

M48T128Y
M48T128V
5.0 or 3.3 V, 1 Mbit (128 Kb x 8) TIMEKEEPER® SRAM
Features
■
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):
– M48T128Y: VCC = 4.5 to 5.5 V
4.1 V ≤ VPFD ≤ 4.5 V
– M48T128V: VCC = 3.0 to 3.6 V
2.7 V ≤ VPFD ≤ 3.0 V
(contact the ST sales office for availability)
■
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
■
Self-contained battery and crystal in the DIP
package
■
Pin and function compatible with JEDEC
standard 128 K x 8 SRAMs
■
RoHS compliant
– Lead-free second level interconnect
June 2010
Doc ID 5746 Rev 6
32
1
PMDIP32 module (PM)
1/23
www.st.com
1
Contents
M48T128Y, M48T128V
Contents
1
Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2
Operation modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3
2.1
READ mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.2
WRITE mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.3
Data retention mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Clock operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
3.1
Reading the clock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
3.2
Setting the clock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
3.3
Stopping and starting the oscillator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
3.4
Calibrating the clock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
3.5
VCC noise and negative going transients . . . . . . . . . . . . . . . . . . . . . . . . . 14
4
Maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
5
DC and AC parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
6
Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
7
Environmental information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
8
Part numbering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
9
Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
2/23
Doc ID 5746 Rev 6
M48T128Y, M48T128V
List of tables
List of tables
Table 1.
Table 2.
Table 3.
Table 4.
Table 5.
Table 6.
Table 7.
Table 8.
Table 9.
Table 10.
Table 11.
Table 12.
Table 13.
Table 14.
Signal names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Operating modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
READ mode AC characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
WRITE mode AC characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Register map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Operating and AC measurement conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Capacitance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
DC characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Power down/up AC characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Power down/up trip points DC characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
PMDIP32 – 32-pin plastic module DIP, package mechanical data. . . . . . . . . . . . . . . . . . . 19
Ordering information scheme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Document revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Doc ID 5746 Rev 6
3/23
List of figures
M48T128Y, M48T128V
List of figures
Figure 1.
Figure 2.
Figure 3.
Figure 4.
Figure 5.
Figure 6.
Figure 7.
Figure 8.
Figure 9.
Figure 10.
Figure 11.
Figure 12.
4/23
Logic diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
DIP connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
READ mode AC waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
WRITE enable controlled, WRITE AC waveform . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Chip enable controlled, WRITE AC waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Crystal accuracy across temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Clock calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Supply voltage protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
AC testing load circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Power down/up mode AC waveforms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Recycling symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Doc ID 5746 Rev 6
M48T128Y, M48T128V
1
Description
Description
The M48T128Y/V TIMEKEEPER® RAM is a 128 Kb x 8 non-volatile static RAM and realtime clock. The special DIP package provides a fully integrated battery-backed memory and
real-time clock solution. The M48T128Y/V directly replaces industry standard 128 Kb x 8
SRAM.
It also provides the non-volatility of Flash without any requirement for special WRITE timing
or limitations on the number of WRITEs that can be performed. The 32-pin, 600 mil DIP
hybrid houses a controller chip, SRAM, quartz crystal, and a long-life lithium button cell in a
single package.
Figure 1.
Logic diagram
VCC
17
8
A0-A16
W
DQ0-DQ7
M48T128Y
M48T128V
E
G
VSS
AI02244
Table 1.
Signal names
A0-A16
DQ0-DQ7
Address inputs
Data inputs / outputs
E
Chip enable
G
Output enable
W
WRITE enable
VCC
Supply voltage
VSS
Ground
NC
Not connected internally
Doc ID 5746 Rev 6
5/23
Description
M48T128Y, M48T128V
Figure 2.
DIP connections
NC
A16
A14
A12
A7
A6
A5
A4
A3
A2
A1
A0
DQ0
DQ1
DQ2
VSS
1
32
2
31
30
3
29
4
28
5
27
6
26
7
8 M48T128Y 25
9 M48T128V 24
23
10
22
11
21
12
20
13
19
14
18
15
17
16
VCC
A15
NC
W
A13
A8
A9
A11
G
A10
E
DQ7
DQ6
DQ5
DQ4
DQ3
AI02245
Figure 3.
Block diagram
8x8
TIMEKEEPER
REGISTERS
OSCILLATOR AND
CLOCK CHAIN
32,768 Hz
CRYSTAL
A0-A16
POWER
131,064 x 8
SRAM ARRAY
LITHIUM
CELL
DQ0-DQ7
E
VOLTAGE SENSE
AND
SWITCHING
CIRCUITRY
W
VPFD
VCC
G
VSS
AI01804
6/23
Doc ID 5746 Rev 6
M48T128Y, M48T128V
2
Operation modes
Operation modes
Figure 3 on page 6 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 - valid until 2100), 30, and 31 day
months are made automatically. Byte 1FFF8h is the clock control register. This byte controls
user access to the clock information and also stores the clock calibration setting. The seven
clock bytes (1FFFFh - 1FFF8h) are not the actual clock counters, they are memory locations
consisting of BiPORT™ READ/WRITE memory cells within the static RAM array. The
M48T128Y/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 M48T128Y/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 external SRAM, providing data security in the midst of
unpredictable system operation. As VCC falls below the battery backup switchover voltage
(VSO), the control circuitry automatically switches to the battery, maintaining data and clock
operation until valid power is restored.
Table 2.
Mode
Operating modes
VCC
Deselect
WRITE
READ
4.5 to 5.5 V
or
3.0 to 3.6 V
READ
Deselect
Deselect
VSO to VPFD
(min)(1)
≤ VSO(1)
E
G
W
DQ0-DQ7
Power
VIH
X
X
High Z
Standby
VIL
X
VIL
DIN
Active
VIL
VIL
VIH
DOUT
Active
VIL
VIH
VIH
High Z
Active
X
X
X
High Z
CMOS standby
X
X
X
High Z
Battery backup mode
1. See Table 11 on page 18 for details.
Note:
X = VIH or VIL; VSO = battery backup switchover voltage.
Doc ID 5746 Rev 6
7/23
Operation modes
2.1
M48T128Y, M48T128V
READ mode
The M48T128Y/V is in the READ mode whenever W (WRITE enable) is high and E (chip
enable) is low. The unique address specified by the 17 address inputs defines which one of
the 131,072 bytes of data is to be accessed.
Valid data will be available at the data I/O pins within tAVQV (address access time) 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 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 tAXQX (output
data hold time) but will go indeterminate until the next address access.
Figure 4.
READ mode AC waveforms
tAVAV
VALID
A0-A16
tAXQX
tAVQV
tELQV
tEHQZ
E
tELQX
tGLQV
tGHQZ
G
tGLQX
DQ0-DQ7
DATA OUT
Note:
WE = High.
Table 3.
READ mode AC characteristics
M48T128Y
M48T128V
–70
–85
Parameter(1)
Symbol
AI01197
Min
Max
Min
Unit
Max
tAVAV
READ cycle time
tAVQV
Address valid to output valid
70
85
ns
tELQV
Chip enable low to output valid
70
85
ns
tGLQV
Output enable low to output valid
40
55
ns
tELQX(2)
tGLQX(2)
tEHQZ(2)
tGHQZ(2)
tAXQX
70
Chip enable low to output transition
5
Output enable low to output transition
5
85
ns
5
ns
5
ns
Chip enable high to output Hi-Z
25
30
ns
Output enable high to output Hi-Z
25
30
ns
Address transition to output transition
10
5
1. Valid for ambient operating temperature: TA = 0 to 70 °C; VCC = 4.5 to 5.5 V or 3.0 to 3.6 V (except where noted).
2. CL = 5 pF.
8/23
Doc ID 5746 Rev 6
ns
M48T128Y, M48T128V
2.2
Operation modes
WRITE mode
The M48T128Y/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 5.
WRITE enable controlled, WRITE AC waveform
tAVAV
VALID
A0-A16
tAVWH
tAVEL
tWHAX
E
tWLWH
tAVWL
W
tWLQZ
tWHQX
tWHDX
DQ0-DQ7
DATA INPUT
tDVWH
AI02382
Figure 6.
Chip enable controlled, WRITE AC waveforms
tAVAV
VALID
A0-A16
tAVEH
tAVEL
tELEH
tEHAX
E
tAVWL
W
tEHDX
DQ0-DQ7
DATA INPUT
tDVEH
AI02383
Doc ID 5746 Rev 6
9/23
Operation modes
M48T128Y, M48T128V
Table 4.
Symbol
WRITE mode AC characteristics
M48T128Y
M48T128V
–70
–85
Parameter(1)
Min
Max
Min
Unit
Max
tAVAV
WRITE cycle time
70
85
ns
tAVWL
Address valid to WRITE enable low
0
0
ns
tAVEL
Address valid to chip enable low
0
0
ns
tWLWH
WRITE enable pulse width
50
60
ns
tELEH
Chip enable low to chip enable 1 high
55
65
ns
tWHAX
WRITE enable high to address transition
5
5
ns
tEHAX
Chip enable high to address transition
10
15
ns
tDVWH
Input valid to WRITE enable high
30
35
ns
tDVEH
Input valid to chip enable high
30
35
ns
tWHDX
WRITE enable high to input transition
5
5
ns
tEHDX
Chip enable high to input transition
10
15
ns
tWLQZ(2)(3)
WRITE enable low to output Hi-Z
25
30
ns
tAVWH
Address valid to WRITE enable high
60
70
ns
tAVEH
Address valid to chip enable high
60
70
ns
WRITE enable high to output transition
5
5
ns
tWHQX
(2)(3)
1. Valid for ambient operating temperature: TA = 0 to 70 °C; VCC = 4.5 to 5.5 V or 3.0 to 3.6 V (except where
noted).
2. CL = 5 pF.
3. If E goes low simultaneously with W going low, the outputs remain in the high impedance state.
2.3
Data retention mode
With valid VCC applied, the M48T128Y/V operates as a conventional BYTEWIDE™ static
RAM. Should the supply voltage decay, the RAM will automatically power-fail deselect, write
protecting itself when VCC falls within the 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 currently addressed location,
but does not jeopardize the rest of the RAM's content. At voltages below VPFD (min), the
user can be assured the memory will be in a write protected state, provided the VCC fall time
is not less than tF. The M48T128Y/V may respond to transient noise spikes on VCC that
reach 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
M48T128Y/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. Deselect continues for tREC after VCC reaches VPFD (max).
10/23
Doc ID 5746 Rev 6
M48T128Y, M48T128V
3
Clock operations
3.1
Reading the clock
Clock operations
Updates to the TIMEKEEPER® registers should be halted before clock data is read to
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 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 (1FFF8h).
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 is within a second
after the bit is reset to a '0.'
3.2
Setting the clock
Bit D7 of the control register (1FFF8h) 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 on page 12).
Resetting the WRITE bit to a '0' then transfers the values of all time registers 1FFFFh1FFF9h to the actual TIMEKEEPER counters and allows normal operation to resume. After
the WRITE bit is reset, the next clock update will occur one second later.
3.3
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 1FFF9h. Setting it to a '1' stops the
oscillator. The M48T128Y/V is shipped from STMicroelectronics with the STOP bit set to a
'1.' When reset to a '0,' the M48T128Y/V oscillator starts after one second.
Doc ID 5746 Rev 6
11/23
Clock operations
Table 5.
M48T128Y, M48T128V
Register map
Data
Function/range
Address
D7
D6
1FFFEh
0
0
0
1FFFDh
0
0
10 date
1FFFCh
0
FT
1FFFBh
0
0
1FFFAh
0
1FFF9h
ST
1FFF8h
W
1FFFFh
D5
D4
D3
D2
10 years
D1
D0
BCD format
Year
Year
00-99
Month
Month
01-12
Date
Date
01-31
Day
01-07
Hours
Hours
00-23
10 minutes
Minutes
Minutes
00-59
10 seconds
Seconds
Seconds
00-59
10 M
0
0
0
Day
10 hours
R
S
Calibration
Control
Keys:
S = SIGN bit
R = READ bit
W = WRITE bit
ST = STOP bit
0 = Must be set to '0'
Z = '0' and are Read only
Y = '1' or '0'
3.4
Calibrating the clock
The M48T128Y/V is driven by a quartz controlled oscillator with a nominal frequency of
32,768 Hz. The devices are factory calibrated at 25 °C and tested for accuracy. Clock
accuracy will not exceed 35 ppm (parts per million) oscillator frequency error at 25 °C, 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 25 °C. The oscillation rate of
crystals changes with temperature (see Figure 7 on page 13). The M48T128Y/V design
employs periodic counter correction. The calibration circuit adds or subtracts counts from
the oscillator divider circuit at the divide by 128 stage, as shown in Figure 8 on 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
1FFF8h. 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 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 32,768 Hz, 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.
12/23
Doc ID 5746 Rev 6
M48T128Y, M48T128V
Clock operations
One method is available for ascertaining how much calibration a given M48T128Y/V may
require. This 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 the STMicroelectronics application note, “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 byte. For
example, a deviation of 21 seconds slow over a period of 30 days would indicate a –8 ppm
oscillator frequency error, requiring a +2(WR100010) to be loaded into the calibration byte
for correction.
Figure 7.
Crystal accuracy across temperature
ppm
20
0
-20
-40
ΔF = -0.038 ppm (T - T )2 ± 10%
0
F
C2
-60
T0 = 25 °C
-80
-100
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
°C
AI02124
Figure 8.
Clock calibration
NORMAL
POSITIVE
CALIBRATION
NEGATIVE
CALIBRATION
AI00594B
Doc ID 5746 Rev 6
13/23
Clock operations
3.5
M48T128Y, M48T128V
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 0.1 µF (as shown in
Figure 9) 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, it is recommended to connect 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 9.
Supply voltage protection
VCC
VCC
0.1µF
DEVICE
VSS
AI02169
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M48T128Y, M48T128V
4
Maximum ratings
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 conditions above those indicated in the operating sections of
this specification is not implied. Exposure to absolute maximum rating conditions for
extended periods may affect device reliability.
Table 6.
Absolute maximum ratings
Symbol
TA
TSTG
TSLD(1)(2)
Parameter
Ambient operating temperature
Storage temperature (VCC off, oscillator off)
Value
Unit
0 to 70
°C
–40 to 85
°C
260
°C
–0.3 to 7
V
M48T128Y
–0.3 to 7
V
M48T128V
–0.3 to 4.6
V
Lead solder temperature for 10 seconds
VIO
Input or output voltages
VCC
Supply voltage
IO
Output current
20
mA
PD
Power dissipation
1
W
1. Soldering temperature of the IC leads is to not exceed 260 °C for 10 seconds. In order to protect the lithium
battery, preheat temperatures must be limited such that the battery temperature does not exceed +85 °C.
Furthermore, the devices shall not be exposed to IR reflow.
2. For DIP packaged devices, ultrasonic vibrations should not be used for post-solder cleaning to avoid
damaging the crystal.
Caution:
Negative undershoots below –0.3 V are not allowed on any pin while in the battery backup
mode.
Doc ID 5746 Rev 6
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DC and AC parameters
5
M48T128Y, M48T128V
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)
M48T128Y
M48T128V
Unit
4.5 to 5.5
3.0 to 3.6
V
0 to 70
0 to 70
°C
Load capacitance (CL)
100
50
pF
Input rise and fall times
≤5
≤5
ns
0 to 3
0 to 3
V
1.5
1.5
V
Input pulse voltages
Input and output timing ref. voltages
Note:
Output Hi-Z is defined as the point where data is no longer driven.
Figure 10. AC testing load circuit
650Ω
DEVICE
UNDER
TEST
1.75V
CL = 100pF
or 50pF(1)
CL includes JIG capacitance
AI03630
1. 50 pF for M48T128V.
Table 8.
Capacitance
Parameter(1)(2)
Symbol
CIN
CIO(3)
Min
Max
Unit
Input capacitance
-
20
pF
Input / output capacitance
-
20
pF
1. Effective capacitance measured with power supply at 5 V. Sampled only, not 100% tested.
2. At 25 °C, f = 1 MHz.
3. Outputs deselected.
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M48T128Y, M48T128V
Table 9.
Symbol
DC and AC parameters
DC characteristics
Parameter
M48T128Y
M48T128V
–70
–85
Test condition(1)
Min
ILI
ILO
(2)
Input leakage current
Output leakage current
Max
Min
Unit
Max
0 V ≤ VIN ≤ VCC
±2
±2
µA
0 V ≤ VOUT ≤ VCC
±2
±2
µA
Outputs open
95
50
mA
E = VIH
8
4
mA
E = VCC – 0.2 V
4
3
mA
ICC
Supply current
ICC1
Supply current (standby) TTL
ICC2
Supply current (standby) CMOS
VIL
Input low voltage
–0.3
0.8
–0.3
0.4
V
VIH
Input high voltage
2.2
VCC + 0.3
2.2
VCC + 0.3
V
VOL
Output low voltage
IOL = 2.1 mA
0.4
V
VOH
Output high voltage
IOH = –1 mA
0.4
2.4
2.2
V
1. Valid for ambient operating temperature: TA = 0 to 70 °C; VCC = 4.5 to 5.5 V or 3.0 to 3.6 V (except where noted).
2. Outputs deselected.
Doc ID 5746 Rev 6
17/23
DC and AC parameters
M48T128Y, M48T128V
Figure 11. Power down/up mode AC waveforms
VCC
VPFD (max)
VPFD (min)
VSS
tDR
tF
tREC
tFB
INPUTS
tRB
DON'T CARE
RECOGNIZED
RECOGNIZED
HIGH-Z
OUTPUTS
VALID
VALID
AI03612
Table 10.
Power down/up AC characteristics
Parameter(1)
Symbol
(2)
Min
Max
Unit
VPFD (max) to VPFD (min) VCC fall time
300
µs
VPFD (min) to VSS VCC fall time
10
µs
tR
VPFD (min) to VPFD (max) VCC rise time
0
µs
tRB
VSS to VPFD (min) VCC rise time
1
µs
tREC
VPFD (max) to inputs recognized
40
tF
tFB(3)
200
ms
1. Valid for ambient operating temperature: TA = 0 to 70 °C; VCC = 4.5 to 5.5 V or 3.0 to 3.6 V (except where noted).
2. VPFD (max) to VPFD (min) fall time of less than tF may result in deselection/write protection not occurring until 200 µs 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
Parameter(1)(2)
Symbol
VPFD
Power-fail deselect voltage
VSO
Battery backup switchover voltage
tDR(3)
Expected data retention time
Min
Typ
Max
Unit
M48T128Y
4.1
4.35
4.5
V
M48T128V
2.7
2.9
3.0
V
M48T128Y
3.0
M48T128V
VPFD – 100 mV
10
1. All voltages referenced to VSS.
2. Valid for ambient operating temperature: TA = 0 to 70 °C; VCC = 4.5 to 5.5 V or 3.0 to 3.6 V (except where noted).
3. At 25 °C; VCC = 0 V.
18/23
Doc ID 5746 Rev 6
V
V
YEARS
M48T128Y, M48T128V
6
Package mechanical data
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: www.st.com.
ECOPACK® is an ST trademark.
Figure 1. PMDIP32 – 32-pin plastic module DIP, package outline
A
A1
B
S
L
C
eA
e1
e3
D
N
E
1
PMDIP
Note:
Drawing is not to scale.
Table 12.
PMDIP32 – 32-pin plastic module DIP, package mechanical data
mm
inches
Symb
Typ
A
Min
Max
9.27
Typ
Min
Max
9.52
0.365
0.375
A1
0.38
–
0.015
–
B
0.43
0.59
0.017
0.023
C
0.20
0.33
0.008
0.013
D
42.42
43.18
1.670
1.700
E
18.03
18.80
0.710
0.740
e1
2.29
2.79
0.090
0.110
e3
38.1
1.5
eA
14.99
16.00
0.590
0.630
L
3.05
3.81
0.120
0.150
S
1.91
2.79
0.075
0.110
N
32
Doc ID 5746 Rev 6
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Environmental information
7
M48T128Y, M48T128V
Environmental information
Figure 12. 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
and local/national disposal and recycling regulations.
Please refer to the following web site address for additional information regarding
compliance statements and waste recycling.
Go to www.st.com/nvram, then select "Lithium Battery Recycling" from "Related Topics".
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M48T128Y, M48T128V
8
Part numbering
Part numbering
Table 13.
Ordering information scheme
Example:
M48T
128Y
–70
PM
1
Device type
M48T
Supply voltage and write protect voltage
128Y = VCC = 4.5 to 5.5 V; VPFD = 4.1 to 4.5 V
128V(1) = VCC = 3.0 to 3.6 V; VPFD = 2.7 to 3.0 V
Speed
–70 = 70 ns (128Y)
–85 = 85 ns (128V)
Package
PM = PMDIP32
Temperature range
1 = 0 to 70°C
Shipping method
blank = Ecopack® package, tubes
1. Contact local ST sales office for availability of 3.3 V version.
For other options, or for more information on any aspect of this device, please contact the
ST sales office nearest you.
Doc ID 5746 Rev 6
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Revision history
9
M48T128Y, M48T128V
Revision history
Table 14.
Document revision history
Date
Revision
Jun-1998
1
First issue
31-Jan-2000
1.1
Calibrating the clock paragraph changed
30-Mar-2000
1.2
Storage temperature changed (Table 6)
20-Jul-2001
2
21-Sep-2001
2.1
Corrected speed grade in ordering information
23-May-2002
2.2
Add countries to disclaimer; add marketing status
07-Aug-2002
2.3
Refine marketing status text
Reformatted; temperature information added to tables (Table 8, 9, 3, 4,
10, 11)
28-Mar-2003
3
v2.2 template applied; test condition updated (Table 11)
06-Aug-2004
4
Reformatted; updated register map (Table 5)
22-Feb-2005
5
IR reflow update (Table 6)
6
Updated Features, Section 4, Table 12, 13; added ECOPACK® text to
Section 6; added Section 7: Environmental information; reformatted
document.
18-Jun-2010
22/23
Changes
Doc ID 5746 Rev 6
M48T128Y, M48T128V
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Doc ID 5746 Rev 6
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