DS2045W Datasheet, PDF (1/12 Pages) Maxim Integrated Products – 3.3V Single-Piece 1Mb Nonvolatile SRAM

Rev 1; 1/05
DS2045W 3.3V Single-Piece 1Mb
Nonvolatile SRAM
General Description
The DS2045W is a 1Mb reflowable nonvolatile (NV)
SRAM, which consists of a static RAM (SRAM), an NV
controller, and an internal rechargeable manganese
lithium (ML) battery. These components are encased in
a surface-mount module with a 256-ball BGA footprint.
Whenever V_CC is applied to the module, it recharges the
ML battery, powers the SRAM from the external power
source, and allows the contents of the SRAM to be mod-
ified. When V_CC is powered down or out of tolerance,
the controller write-protects the SRAM’s contents and
powers the SRAM from the battery. The DS2045W also
contains a power-supply monitor output, RST, which can
be used as a CPU supervisor for a microprocessor.
RAID Systems and Servers
Industrial Controllers
Gaming
Router/Switches
Applications
POS Terminals
Data-Acquisition Systems
Fire Alarms
PLC
Features
♦ Single-Piece, Reflowable, 27mm² PBGA Package
Footprint
♦ Internal ML Battery and Charger
♦ Unconditionally Write-Protects SRAM when V_CC
is Out-of-Tolerance
♦ Automatically Switches to Battery Supply when
V_CC Power Failures Occur
♦ Internal Power-Supply Monitor Detects Power Fail
Below Nominal V_CC (3.3V)
♦ Reset Output can be used as a CPU Supervisor
for a Microprocessor
♦ Industrial Temperature Range (-40°C to +85°C)
♦ UL Recognized
Pin Configuration appears at end of data sheet.
PART
DS2045W-100
TEMP RANGE
-40°C to +85°C
PIN-PACKAGE
256 Ball 27mm² BGA Module
Ordering Information
SPEED (ns)
100
SUPPLY TOLERANCE (%)
3.3V ±0.3V
Typical Operating Circuit
(CE0)
P4.0
(WR)
P3.6
(RD)
P3.7
8051 ^AD0–AD7
MICROPROCESSOR
P1.0–7
P4.4
P2.0–7
(INT0)
P3.2
8 BITS
8 BITS
8 BITS
CE
WE
OE
DS2045W
DQ0–7 _{128k x 8}
NV SRAM
A0–7
A16
A8–15
RST
______________________________________________ Maxim Integrated Products 1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.