DS1553
64kB, Nonvolatile, Year-2000-Compliant
Timekeeping RAM
www.maxim-ic.com
GENERAL DESCRIPTION
The DS1553 is a full-function, year-2000-compliant
(Y2KC) real-time clock/calendar (RTC) with an RTC
alarm, watchdog timer, power-on reset, battery
monitor, and 8k x 8 nonvolatile static RAM. User
access to all registers within the DS1553 is
accomplished with a bytewide interface as shown in
Figure 1. The RTC registers contain century, year,
month, date, day, hours, minutes, and seconds data in
24-hour BCD format. Corrections for day of month and
leap year are made automatically.
FEATURES
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§
Integrated NV SRAM, RTC, Crystal, Power-Fail
Control Circuit, and Lithium Energy Source
Clock Registers are Accessed Identically to the
Static RAM; These Registers are Resident in the 16
Top RAM Locations
Totally Nonvolatile with Over 10 Years of
Operation in the Absence of Power
Precision Power-On Reset
Programmable Watchdog Timer and RTC Alarm
BCD-Coded Year, Month, Date, Day, Hours,
Minutes, and Seconds with Automatic Leap Year
Compensation Valid Up to the Year 2100
Battery Voltage Level Indicator Flag
Power-Fail Write Protection Allows for
±10%
V
CC
Power-Supply Tolerance
Lithium Energy Source is Electrically
Disconnected to Retain Freshness Until Power is
Applied for the First Time
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§
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ORDERING INFORMATION
PART
DS1553-100
DS1553-70
DS1553P-100
DS1553P-70
DS1553W-120
DS1553W-150
DS1553WP-120
DS1553WP-150
DS9034PCX*
PIN-PACKAGE
28 EDIP
28 EDIP
34 PowerCap
®
34 PowerCap
28 EDIP
28 EDIP
34 PowerCap
34 PowerCap
—
V
CC
(V)
5.0
5.0
5.0
5.0
3.3
3.3
3.3
3.3
—
TOP MARK
DS1553-100
DS1553-070
DS1553P-100
DS1553P-70
DS1553W-120
DS1553W-150
DS1553WP-120
DS1553WP-150
DS9034PCX
§
§
§
*
PowerCap required, must be ordered separately.
PIN CONFIGURATIONS
TOP VIEW
RST
A12
A7
A6
A5
A4
A3
A2
A1
A0
DQ0
DQ1
DQ2
GND
1
28
2
27
3
DS1553
26
4
25
5
24
6
23
7
22
8
21
9
20
10
19
11
18
12
17
13
16
14
15
V
CC
WE
IRQ/FT
A8
A9
A11
OE
A10
CE
DQ7
DQ6
DQ5
DQ4
DQ3
IRQ/FT
N.C.
N.C.
RST
V
CC
WE
OE
CE
DQ7
DQ6
DQ5
DQ4
DQ3
DQ2
DQ1
DQ0
GND
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
34
33
32
31
30
29
28
27
26
25
24
23
22
21
20
19
18
N.C.
N.C.
N.C.
N.C.
A12
A11
A10
A9
A8
A7
A6
A5
A4
A3
A2
A1
A0
DS1553
28-Pin Encapsulated Package
(700-mil Extended)
X1
GND
V
BAT
X2
34-Pin PowerCap Module Board
(Uses DS9034PCX PowerCap)
PowerCap is a registered trademark of Dallas Semiconductor.
Note:
Some revisions of this device may incorporate deviations from published specifications known as errata. Multiple revisions of any device
may be simultaneously available through various sales channels. For information about device errata, click here:
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REV: 022304