Features
➤ 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 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-
cles of standard SRAM.
The control circuitry constantly
monitors the single 5V supply for an
out-of-tolerance condition. When
V
CC falls out of tolerance, the SRAM
is unconditionally write-protected to
prevent inadvertent write operation.
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
DQ0–DQ7 Data input/output
CE Chip enable input
OE Output enable input
WE Write enable input
NC No connect
VCC Supply voltage input
VSS Ground
Selection Guide
Part
Number
Maximum
Access
Time (ns)
Negative
Supply
Tolerance
Part
Number
Maximum
Access
Time (ns)
Negative
Supply
Tolerance
bq4013YMA -70 70 -10%
bq4013MA -85 85 -5% bq4013YMA -85 85 -10%
bq4013MA-120 120 -5% bq4013YMA-120 120 -10%
128Kx8 Nonvolatile SRAM
Pin Names