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PRELIMINARY DATA
January 1998
This is preliminary information on a new product now in development or undergoing evaluation. Details are subject to change without notice.
M48T39Y
256 Kb (32K x8) TIMEKEEPER
SRAM
s
INTEGRATED ULTRA LOW POWER SRAM,
REAL TIME CLOCK, POWER-FAIL CONTROL
CIRCUIT, BATTERY and CRYSTAL
s
BCD CODED YEAR, MONTH, DAY, DATE,
HOURS, MINUTES and SECONDS
s
AUTOMATIC POWER-FAIL CHIP DESELECT
and WRITE PROTECTION
s
WRITE PROTECT VOLTAGE
(V
PFD
= Power-fail Deselect Voltage):
M48T39Y: 4.20V
V
PFD
4.50V
s
PROGRAMMABLE INTERRUPTS and
SQUARE WAVE OUTPUT
s
WATCHDOG TIMER RESTARTS on
OUT-OF-CONTROL PROCESSOR
s
CLOCK ACCURACY IS BETTER THAN
1 MINUTE per MONTH at 25C
s
10 YEARS of DATA RETENTION and CLOCK
OPERATION in the ABSENCE of POWER
s
SELF-CONTAINED BATTERY and CRYSTAL
in DIP PACKAGE
s
PROGRAMMABLE ALARM OUTPUT ACTIVE
in the BATTERY BACK-UP MODE
s
PIN and FUNCTION COMPATIBLE with
DS1386
DESCRIPTION
The M48T39Y TIMEKEEPER
RAM is a non-vol-
atile 262,144 bit static RAM and real time clock or-
ganized as 32,768 words by 8 bits. System
integration features include Programmable
Alarms, Watchdog Timer and Interval Timer. The
special 32-pin DIP package provides a highly inte-
grated battery back-up memory and real time
clock solution.
Figure 1. Logic Diagram
AI02311
15
A0-A14
W
DQ0-DQ7
VCC
M48Z129Y
G
VSS
8
E
INTA
INTB
SQW
32
1
PMDIP32 (PM)
Module
M48T39Y
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Figure 2. DIP Connections
A1
A0
DQ0
A7
A4
A3
A2
A6
A5
A13
A10
A8
A9
DQ7
SQW
A11
G
E
DQ5
DQ1
DQ2
DQ3
VSS
DQ4
DQ6
INTB
INTA
VCC
AI02312
10
1
2
5
6
7
8
9
11
12
13
14
15
16
30
29
26
25
24
23
22
21
20
19
18
17
A12
A14
W
VCC
3
4
28
27
32
31
M48T39Y
Table 1. Signal Names
A0-A14
Address Inputs
DQ0-DQ7
Data Inputs / Outputs
E
Chip Enable Input
G
Output Enable Input
W
Write Enable Input
INTA
Interrupt Output A (Open Drain)
INTB
Interrupt Output B (Open Drain)
SQW
Square Wave Output
V
CC
Supply Voltage
V
SS
Ground
Table 2. Ordering Information Scheme
For a list of available options (Speed, Package, etc...) or for further information on any aspect of this de-
vice, please contact the ST Sales Office nearest to you.
Example:
M48T39Y
-100 PM
1
Device Type
M48T
Supply Voltage and Write Protect Voltage
39Y = V
CC
= 4.5V to 5.5V; V
PFD
= 4.2V to 4.5V
Speed
-100 = 100ns
-150 = 150ns
Package
PM = PMDIP32
Temperature Range
1 = 0 to 70 C
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M48T39Y
Table 3. PMDIP32 - 32 pin Plastic Module DIP, Package Mechanical Data
Symb
mm
inches
Typ
Min
Max
Typ
Min
Max
A
9.27
9.52
0.3650
0.3748
A1
0.38
0.0150
B
0.43
0.59
0.0169
0.0232
C
0.20
0.33
0.0079
0.0130
D
42.42
43.18
1.6701
1.7000
E
18.03
18.80
0.7098
0.7402
e1
2.29
2.79
0.0902
0.1098
e3
34.29
41.91
1.3500
1.6500
eA
14.99
16.00
0.5902
0.6299
L
3.05
3.81
0.1201
0.1500
S
1.91
2.79
0.0752
0.1098
N
32
32
Figure 3. PMDIP32 - 32 pin Plastic Module DIP, Package Outline
Drawing is not to scale.
PMDIP
A1
A
L
B
e1
D
E
N
1
eA
e3
S
C
M48T39Y
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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.
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