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
➤
34-pin LIFETIME LITHIUM™
module
-
-
Snap-on power-source for
lithium battery backup
Replaceable power-source
(part number: bq40MS)
prevent inadvertent write opera-
tion.
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.
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
-
Module completely
surface-mounted
Pin Connections
Pin Names
A
0
–A
16
DQ
0
–DQ
7
NC
A15
A16
NC
V
CC
WE
OE
CE
DQ
7
DQ
6
DQ
5
DQ
4
DQ
3
DQ
2
DQ
1
DQ
0
V
SS
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
34
33
32
31
30
29
28
27
26
25
24
23
22
21
20
19
18
NC
NC
A14
A13
A12
A11
A10
A9
A8
A7
A6
A5
A4
A3
A2
A1
A0
Address inputs
Data input/output
Chip enable input
Output enable input
Write enable input
No connect
Supply voltage input
Ground
CE
OE
WE
NC
V
CC
V
SS
34-Pin LIFETIME LITHIUM Module
PN4013Ygs.eps
Selection Guide
Part
Number
bq4013x -85
bq4013x -120
Maximum
Access
Time (ns)
85
120
Negative
Supply
Tolerance
-5%
-5%
Part
Number
bq4013Yx -70
bq4013Yx -85
bq4013Yx -120
Maximum
Access
Time (ns)
70
85
120
Negative
Supply
Tolerance
-10%
-10%
-10%
Note:
x = MA for PDIP module or MS for LIFETIME LITHIUM module.
5/99 E
1
bq4013/Y
Functional Description
When power is valid, the bq4013/Y operates as a stan-
dard CMOS SRAM. During power-down and power-up
cycles, the bq4013/Y acts as a nonvolatile memory, auto-
matically protecting and preserving the memory con-
tents.
Power-down/power-up control circuitry constantly moni-
tors the V
CC
supply for a power-fail-detect threshold
V
PFD
. The bq4013 monitors for V
PFD
= 4.62V typical for
use in systems with 5% supply tolerance. The bq4013Y
monitors for V
PFD
= 4.37V typical for use in systems
with 10% supply tolerance.
When V
CC
falls below the V
PFD
threshold, the SRAM au-
tomatically write-protects the data. All outputs become
high impedance, and all inputs are treated as “don’t
care.” If a valid access is in process at the time of
power-fail detection, the memory cycle continues to com-
pletion. If the memory cycle fails to terminate within
time t
WPT
, write-protection takes place.
As V
CC
falls past V
PFD
and approaches 3V, the control
circuitry switches to the internal lithium backup supply,
which provides data retention until valid V
CC
is applied.
When V
CC
returns to a level above the internal backup
cell voltage, the supply is switched back to V
CC
. After
V
CC
ramps above the V
PFD
threshold, write-protection
continues for a time t
CER
(120ms maximum) to allow for
processor stabilization. Normal memory operation may
resume after this time.
The internal coin cell used by the bq4013/Y has an ex-
tremely long shelf life and provides data retention for
more than 10 years in the absence of system power.
As shipped from Unitrode, the integral lithium cell of
the MT-type module is electrically isolated from the
memory. (Self-discharge in this condition is approxi-
mately 0.5% per year.) Following the first application of
V
CC
, this isolation is broken, and the lithium backup cell
provides data retention on subsequent power-downs.
The LIFETIME LITHIUM package option is shipped as
two parts.
Block Diagram
OE
WE
128K x 8
SRAM
Block
A
0
–A
16
DQ
0
–DQ
7
CE
CON
Power
CE
Power-Fail
V
CC
Control
Lithium
Cell
BD-42
2
bq4013/Y
Truth Table
Mode
Not selected
Output disable
Read
Write
CE
H
L
L
L
WE
X
H
H
L
OE
X
H
L
X
I/O Operation
High Z
High Z
D
OUT
D
IN
Power
Standby
Active
Active
Active
Absolute Maximum Ratings
Symbol
V
CC
V
T
T
OPR
T
STG
T
BIAS
T
SOLDER
Note:
Parameter
DC voltage applied on V
CC
relative to V
SS
DC voltage applied on any pin excluding V
CC
relative to V
SS
Operating temperature
Storage temperature
Temperature under bias
Soldering temperature
Value
-0.3 to 7.0
-0.3 to 7.0
0 to +70
-40 to +85
-40 to +70
-40 to +85
-10 to +70
-40 to +85
+260
Unit
V
V
°C
°C
°C
°C
°C
°C
°C
V
T
≤
V
CC
+ 0.3
Commercial
Industrial “N”
Commercial
Industrial “N”
Commercial
Industrial “N”
For 10 seconds
Conditions
Permanent device damage may occur if
Absolute Maximum Ratings
are exceeded. Functional operation
should be limited to the Recommended DC Operating Conditions detailed in this data sheet. Exposure to con-
ditions beyond the operational limits for extended periods of time may affect device reliability.
3
bq4013/Y
Recommended DC Operating Conditions
(TA = TOPR)
Symbol
V
CC
V
SS
V
IL
V
IH
Note:
Parameter
Supply voltage
Supply voltage
Input low voltage
Input high voltage
Minimum
4.5
4.75
0
-0.3
2.2
Typical
5.0
5.0
0
-
-
Maximum
5.5
5.5
0
0.8
V
CC
+ 0.3
Unit
V
V
V
V
V
bq4013Y
bq4013
Notes
Typical values indicate operation at T
A
= 25°C.
DC Electrical Characteristics
(TA = TOPR, VCCmin
Symbol
I
LI
I
LO
V
OH
V
OL
I
SB1
I
SB2
Parameter
Input leakage current
Output leakage current
Output high voltage
Output low voltage
Standby supply current
Standby supply current
Minimum
-
-
2.4
-
-
-
Typical
-
-
-
-
4
2.5
≤
VCC
≤
VCCmax)
Unit
µA
µA
V
V
mA
mA
Conditions/Notes
V
IN
= V
SS
to V
CC
CE = V
IH
or OE = V
IH
or
WE = V
IL
I
OH
= -1.0 mA
I
OL
= 2.1 mA
CE = V
IH
CE
≥
V
CC
- 0.2V,
0V
≤
V
IN
≤
0.2V,
or V
IN
≥
V
CC
- 0.2V
Min. cycle, duty = 100%,
CE = V
IL
, I
I/O
= 0mA
bq4013
bq4013Y
Maximum
±
1
±
1
-
0.4
7
4
I
CC
Operating supply current
-
4.55
75
4.62
4.37
3
105
4.75
4.50
-
mA
V
V
V
V
PFD
V
SO
Note:
Power-fail-detect voltage
4.30
Supply switch-over voltage
-
Typical values indicate operation at T
A
= 25°C, V
CC
= 5V.
Capacitance
(TA = 25°C, F = 1MHz, VCC = 5.0V)
Symbol
C
I/O
C
IN
Note:
Parameter
Input/output capacitance
Input capacitance
Minimum
-
-
Typical
-
-
Maximum
10
10
Unit
pF
pF
Conditions
Output voltage = 0V
Input voltage = 0V
These parameters are sampled and not 100% tested.
4
bq4013/Y
AC Test Conditions
Parameter
Input pulse levels
Input rise and fall times
Input and output timing reference levels
Output load (including scope and jig)
Test Conditions
0V to 3.0V
5 ns
1.5 V (unless otherwise specified)
See Figures 1 and 2
Figure 1. Output Load A
Figure 2. Output Load B
Read Cycle
Symbol
t
RC
t
AA
t
ACE
t
OE
t
CLZ
t
OLZ
t
CHZ
t
OHZ
t
OH
(TA = TOPR, VCCmin
≤
VCC
≤
VCCmax)
-70/-70N
Parameter
Min.
70
-
-
-
5
0
0
0
10
Min.
-
70
70
35
-
-
25
25
-
-85/-85N
Min.
85
-
-
-
5
0
0
0
10
Max.
-
85
85
45
-
-
35
25
-
-120
Min.
120
-
-
-
5
0
0
0
10
Max.
-
120
120
60
-
-
45
35
-
Unit
ns
ns
ns
ns
ns
ns
ns
ns
ns
Output load A
Output load A
Output load A
Output load B
Output load B
Output load B
Output load B
Output load A
Conditions
Read cycle time
Address access time
Chip enable access time
Output enable to output valid
Chip enable to output in low Z
Output enable to output in low Z
Chip disable to output in high Z
Output disable to output in high Z
Output hold from address change
5
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