BQ4013 Datasheet, PDF (1/14 Pages) Texas Instruments – 128Kx8 Nonvolatile SRAM

bq4013/Y
128Kx8 Nonvolatile SRAM
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
VCC 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 VCC 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.
Pin Connections
Pin Names
A0–A16 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)
bq4013MA -85
85
bq4013MA-120
120
9/96 D
Negative
Supply
Tolerance
-5%
-5%
Part
Number
bq4013YMA -70
bq4013YMA -85
bq4013YMA-120
Maximum
Access
Time (ns)
70
85
120
1
Negative
Supply
Tolerance
-10%
-10%
-10%