DS1646 Datasheet, PDF (1/11 Pages) Dallas Semiconductor – Nonvolatile Timekeeping RAM

DS1646/DS1646P
Nonvolatile Timekeeping RAM
www.dalsemi.com
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
PIN ASSIGNMENT
NC 1
A16 ₂
A14 3
A12 4
A7 5
A6 6
A5 7
A4 8
A3 9
A2 10
A1 11
A0 ¹²
DQ0 ¹³
DQ1 14
DQ2 15
GND 16
32
VCC
31 A15
30 NC
29 WE
28 A13
27 A8
26 A9
25 A11
24 ^OE
23 A10
22
CE
21 DQ7
20 DQ6
19 DQ5
18 DQ4
17 DQ3
32-Pin Encapsulated Package
NC
1
34
NC
A15
2
33
NC
A16
3
PFO
4
VCC
WE
5
6
32
A14
31
A13
30
A12
29
A11
OE
CE
DQ7
7
8
9
28
A10
27
A9
26
A8
DQ6
10
25
A7
DQ5
11
DQ4
12
24
A6
23
A5
DQ3
13
22
A4
DQ2
14
21
A3
DQ1
DQ0
15
16
X1
GND VBAT
X2
20
19
A2
A1
GND
17
18
A0
34-Pin PowerCap Module Board
(Uses DS9034PCX PowerCap)
*DS9034PCX
Power Cap
(Required; must be ordered
separately)
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