DS1743/DS1743P
Y2KC Nonvolatile Timekeeping RAM
www.dalsemi.com
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
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 8k x 8 static RAM
pinout
PowerCap
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
NC
A12
A7
A6
A5
A4
A3
A2
A1
A0
DQ0
DQ1
DQ2
GND
1
2
3
4
5
6
7
8
9
10
11
12
13
14
28
27
26
25
24
23
22
21
20
19
18
17
16
15
V
CC
WE
CE2
A8
A9
A11
OE
A10
CE
DQ7
DQ6
DQ5
DQ4
DQ3
28-Pin Encapsulated Package
(700-mil Extended)
NC
NC
NC
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
NC
NC
NC
NC
A12
A11
A10
A9
A8
A7
A6
A5
A4
A3
A2
A1
A0
X1
GND V
BAT
X2
ORDERING INFORMATION
DS1743P-XXX (5V)
-70
-100
blank
P
70 ns access
100 ns access
34-Pin Powercap Module Board
(Uses DS9034PCX Powercap)
PIN DESCRIPTION
A0-A12
CE
28-pin DIP Module
34-pin PowerCap Module
board*
(3.3V)
-120
120 ns access
-150
150 ns access
CE2
OE
WE
*DS1743WP-XXX
28-pin DIP Module
34-pin PowerCap Module
board*
*DS9034PCX (PowerCap) Required:
blank
P
V
CC
GND
DQ0-DQ7
NC
RST
(must be ordered separately)
X1, X2
V
BAT
1 of 17
- Address Input
- Chip Enable
- Chip Enable 2 (DIP
Module only)
- Output Enable
- Write Enable
- Power Supply Input
- Ground
- Data Input/Output
- No Connection
- Power-On Reset Output
(PowerCap Module board only)
- Crystal Connection
- Battery Connection
022301
DALLAS [ DALLAS SEMICONDUCTOR ]
