User guide

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FEATURES
§ Integrated NV SRAM, real-time clock,
crystal, power-fail control circuit and lithium
energy source
§ Clock registers are accessed identical to the
static RAM. These registers are resident in the
eight top RAM locations.
§ Century byte register (Y2K compliant)
§ Totally nonvolatile with over 10 years of
operation in the absence of power
§ BCD coded century, 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
§ DIP Module only
- Standard JEDEC bytewide 512k x 8 static
RAM pinout
§ PowerCap
Ò
Module Board only
- Surface mountable package for direct
connection to PowerCap containing
battery and crystal
- Replaceable battery (PowerCap)
- Power-On Reset Output
- Pin for pin compatible with other densities
of DS174XP Timekeeping RAM
PIN ASSIGNMENT
DS1747/DS1747P
Y2KC Nonvolatile Timekeeping RAM
www.maxim-ic.com
1
NC
2
3
A15
A16
RST
V
CC
WE
OE
CE
DQ7
DQ6
DQ5
DQ4
DQ3
DQ2
DQ1
DQ0
GND
4
5
6
7
8
9
10
11
12
13
14
15
16
17
A
17
A
14
33
32
31
30
29
28
27
26
25
24
23
22
21
20
19
18
A
13
A
12
A
11
A
10
A
9
A
8
A
7
A
6
A
5
A
4
A
3
A
2
A
1
A
0
34
A
18
X1 GND
V
BAT
X2
34-Pin PowerCap Module Board
(Uses DS9034PCX PowerCap)
A18
13
1
2
3
4
5
6
7
8
9
10
11
12
14
31
512k X 8
32-Pin Encapsulated Package
A14
A7
A5
A4
A3
A2
A1
A0
DQ1
DQ0
V
CC
A
15
A
17
WE
A
13
A
8
A
9
A
11
OE
A
10
CE
DQ7
DQ5
DQ6
32
30
29
28
27
26
25
24
23
22
21
19
20
A16
A12
A6
DQ2
GND
15
16
18
17
DQ4
DQ3