DS1330W Datasheet, PDF (1/11 Pages) Dallas Semiconductor – 3.3V 256K Nonvolatile SRAM with Battery Monitor

DS1330W
PRELIMINARY
DS1330W
3.3V 256K Nonvolatile SRAM
with Battery Monitor
FEATURES
• 10 years minimum data retention in the absence of
external power
• Data is automatically protected during power loss
• Power supply monitor resets processor when V_CC
power loss occurs and holds processor in reset during
V_CC ramp–up
• Battery monitor checks remaining capacity daily
• Read and write access times as fast as 150 ns
• Unlimited write cycle endurance
• Typical standby current 50 µA
PIN ASSIGNMENT
BW
1
NC
2
NC
3
RST
4
V_CC
5
WE
6
OE
7
CE
8
DQ7
9
DQ6
10
DQ5
11
DQ4
12
DQ3
13
DQ2
14
DQ1
15
DQ0
16
GND
17
GND V_BAT
34
NC
33
NC
32
A14
31
A13
30
A12
29
A11
28
A10
27
A9
26
A8
25
A7
24
A6
23
A5
22
A4
21
A3
20
A2
19
A1
18
A0
• Upgrade for 32K x 8 SRAM, EEPROM or Flash
• Lithium battery 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
• New PowerCap Module (PCM) package
– Directly surface–mountable module
– Replaceable snap–on PowerCap provides lith-
ium backup battery
– Standardized pinout for all nonvolatile SRAM
products
– Detachment feature on PowerCap allows easy
removal using a regular screwdriver
34–PIN POWERCAP MODULE (PCM)
(USES DS9034PC POWERCAP)
PIN DESCRIPTION
A0–A14
– Address Inputs
DQ0–DQ7 – Data In/Data Out
CE
– Chip Enable
WE
– Write Enable
OE
– Output Enable
RST
– Reset Output
BW
– Battery Warning Output
V_CC
GND
– Power (+3.3 Volts)
– Ground
NC
– No Connect
DESCRIPTION
The DS1330W 3.3V 256K Nonvolatile SRAM is a
262,144–bit, fully static, nonvolatile SRAM organized
as 32,768 words by eight bits. Each NV SRAM has a
self–contained lithium energy source and control cir-
cuitry which constantly monitors V_CC for an out–of–tol-
erance condition. When such a condition occurs, the
lithium energy source is automatically switched on and
write protection is unconditionally enabled to prevent
data corruption. Additionally, the DS1330W has dedi-
cated circuitry for monitoring the status of V_CC and the
status of the internal lithium battery. DS1330W devices
in the PowerCap Module package are directly surface
mountable and are normally paired with a DS9034PC
PowerCap to form a complete Nonvolatile SRAM mod-
ule. The devices can be used in place of 32K x 8 SRAM,
EEPROM or Flash components.
022598 1/11