Features
Data retention for at least 10
years without power
Automatic write-protection during
power-up/power-downcycles
Conventional SRAM operation,
including unlimited write cycles
Internal isolation of battery be-
fore power application
Industry standard 32-pin DIP
pinout
General Description
The CMOS bq4013/Y is a nonvolatile
1,048,576-bit static RAM organized as
131,072 words by 8 bits. The integral
control circuitry and lithium energy
source provide reliable nonvolatility
coupled with the unlimited write cy-
clesofstandardSRAM.
The control circuitry constantly
monitors the single 5V supply for an
out-of-tolerance condition.
V
CC
falls out of tolerance, the SRAM
is unconditionally write-protected to
prevent inadvertent write operation.
When
At this time the integral energy
source is switched on to sustain the
memory until after V
CC
returns valid.
The bq4013/Y uses an extremely
low standby current CMOS SRAM,
coupled with a small lithium coin
cell to provide nonvolatility without
long write-cycle times and the
write-cycle limitations associated
with EEPROM.
The bq4013/Y requires no external
circuitry and is socket-compatible
with industry-standard SRAMs and
most EPROMs and EEPROMs.
1
bq4013/Y
Pin Connections
9/96 D
A
0
–A
16
Address inputs
DQ
0
–DQ
7
Data input/output
CE
Chip enable input
OE
Output enable input
WE
Write enable input
NC
No connect
V
CC
Supply voltage input
V
SS
Ground
Selection Guide
Part
Number
Maximum
Access
Time (ns)
Negative
Supply
Tolerance
Part
Number
Maximum
Access
Time (ns)
Negative
Supply
Tolerance
bq4013YMA -70
bq4013YMA -85
bq4013YMA-120
70
85
120
-10%
-10%
-10%
bq4013MA -85
bq4013MA-120
85
120
-5%
-5%
128Kx8 Nonvolatile SRAM
Pin Names