Not Recommended For New Designs
bq4011/Y/LY
www.ti.com
SLUS118A – MAY 1999 – REVISED MAY 2007
32 k × 8 NONVOLATILE SRAM (5 V, 3.3 V)
FEATURES
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GENERAL DESCRIPTION
Data Retention for at least 10 Years Without
Power
Automatic Write-Protection During
Power-up/Power-down Cycles
Conventional SRAM Operation, Including
Unlimited Write Cycles
Internal Isolation of Battery before Power
Application
5-V or 3.3-V Operation
Industry Standard 28-Pin DIP Pinout
The CMOS bq4011/Y/LY is a nonvolatile 262,144-bit
static RAM organized as 32,768 words by 8 bits. The
integral control circuitry and lithium energy source
provide reliable nonvolatility coupled with the
unlimited write cycles of standard SRAM.
The control circuitry constantly monitors the single
supply for an out-of-tolerance condition. When VCC
falls out of tolerance, the SRAM is unconditionally
write-protected to prevent an inadvertent write
operation.
At this time the integral energy source is switched on
to sustain the memory until after VCC returns valid.
The bq4011/Y/LY uses extremely low standby
current CMOS SRAMs, coupled with small lithium
coin cells to provide nonvolatility without long
write-cycle times and the write-cycle limitations
associated with EEPROM.
The bq4011/Y/LY requires no external circuitry and is
compatible with the industry-standard 256-kb SRAM
pinout.
PIN CONNECTIONS
28−Pin DIP Module
(TOP VIEW)
A14
A12
A7
A6
A5
A4
A3
A2
A1
A0
DQ0
DQ1
DQ2
VSS
1
28
2
27
3
26
4
25
5
24
6
23
7
22
8
21
9
20
10
19
11
18
12
17
13
16
14
15
VCC
WE
A13
A8
A9
A11
OE
A10
CE
DQ7
DQ6
DQ5
DQ4
DQ3
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas
Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 1999–2007, Texas Instruments Incorporated
