User Manual

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FEATURES
 Integrates NV SRAM, real time clock,
crystal, power-fail control circuit and lithium
energy source
 Clock registers are accessed identically to the
static RAM. These registers are resident in
the eight top RAM locations
 Totally nonvolatile with over 10 years of
operation in the absence of power
 BCD coded year, month, date, day, hours,
minutes, and seconds with leap year
compensation valid up to 2100
 Power-fail write protection allows for ±10%
V
CC
power supply tolerance
 DS1646 only (DIP Module)
− Standard JEDEC bytewide 128k x 8 RAM
pinout
 DS1646P only (PowerCap
®
Module Board)
− Surface mountable package for direct
connection to PowerCap containing battery
and crystal
− Replaceable battery (PowerCap)
− Power-fail output
− Pin-for-pin compatible with other densities
of DS164XP Timekeeping RAM
ORDERING INFORMATION
DS1646 32-pin DIP module
*DS1646P 34-pin PowerCap Module
Board
*DS9034PCX Power Cap
(Required; must be ordered
separately)
PIN ASSIGNMENT
DS1646/DS1646P
Nonvolatile Timekeeping RAM
www.dalsemi.com
1
NC
2
3
A15
A16
PFO
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
NC
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
NC
X1 GND V
BAT
X2
34-Pin PowerCap Module Board
(Uses DS9034PCX PowerCap)
13
1
2
3
4
5
6
7
8
9
10
11
12
14
31
32-Pin Encapsulated Package
A14
A7
A5
A4
A3
A2
A1
A0
DQ1
DQ0
V
CC
A
15
NC
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
NC
DQ2
GND
15
16
18
17
DQ4
DQ3