Datasheet

1 of 10
FEATURES
 10 years minimum data retention in the
absence of external power
 Data is automatically protected during power
loss
 Replaces 32k x 8 volatile static RAM,
EEPROM or Flash memory
 Unlimited write cycles
 Low-power CMOS
 Read and write access times of 100ns
 Lithium energy source is electrically
disconnected to retain freshness until power is
applied for the first time
 Optional industrial temperature range of
-40°C to +85°C, designated IND
 JEDEC standard 28-pin DIP package
 PowerCap Module (PCM) package
- Directly surface-mountable module
- Replaceable snap-on PowerCap provides
lithium backup battery
- Standardized pinout for all nonvolatile
SRAM products
- Detachment feature on PowerCap allows
easy removal using a regular screwdriver
PIN ASSIGNMENT
PIN DESCRIPTION
A0 - A14 - Address Inputs
DQ0 - DQ7 - Data In/Data Out
CE
- Chip Enable
WE
- Write Enable
OE
- Output Enable
V
CC
- Power (+3.3V)
GND - Ground
NC - No Connect
DS1230W
3.3V 256k Nonvolatile SRAM
www.maxim-ic.com
13
1
2
3
4
5
6
7
8
9
10
11
12
14
27
28-Pin Encapsulated Package
740-Mil Extended
A7
A5
A3
A2
A1
A0
DQ0
DQ1
GND
DQ2
V
CC
WE
A13
A8
A9
A11
OE
A10
CE
DQ7
DQ6
DQ5
DQ3
DQ4
28
26
25
24
23
22
21
20
19
18
17
15
16
A12
A6
A4
A14
1
NC
2
3
NC
NC
NC
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
A14
33
32
31
30
29
28
27
26
25
24
23
22
21
20
19
18
A13
A12
A11
A10
A9
A8
A7
A6
A5
A4
A3
A2
A1
A0
34
NC
GND
V
BAT
34-Pin PowerCap Module (PCM)
(Uses DS9034PC+ or DS9034PCI+ PowerCap)
19-5636; Rev 11/10