Overview
The LC35256D, LC35256DM, and LC35256DT are
32768-word
8-bit asynchronous silicon gate CMOS
static RAMs. These devices use a 6-transistor full CMOS
memory cell, and feature low-voltage operation, low
current drain, and an ultralow standby current. They
provide two control signal inputs: an OE input for high-
speed access and a chip select (CE) input for device
selection and low power operating mode. This makes
these devices optimal for systems that require low power
or battery backup, and they allow memory to be expanded
easily. Their ultralow standby current allows capacitor-
based backup to be used as well. Since they support 3-V
operation, they are appropriate for use in portable systems
that operate from batteries.
Features
Supply voltage range: 2.7 to 5.5 V
-- 5-V operation:
5.0 V10%
-- 3-V operation:
2.7 to 3.6 V
Access times
-- 5-V operation
LC35256DM, DT-70:
70 ns (max)
LC35256D, DM, DT-10: 100 ns (max)
-- 3-V operation
LC35256DM, DT-70:
200 ns (max)
LC35256D, DM, DT-10: 500 ns (max)
Standby current
-- 5-V operation: 1.0 A (Ta
60C),
5.0 A (Ta
85C)
-- 3-V operation: 0.8 A (Ta
60C),
4.0 A (Ta
85C)
Operating temperature range: 40 to +85C
Data retention supply voltage: 2.0 to 5.5 V
All I/O levels
-- 5-V operation: TTL compatible
-- 3-V operation: V
CC
0.2 V/0.2 V
Shared I/O pins and 3-state outputs
No clock signal required.
Packages
-- 28-pin DIP (600 mil) plastic package: LC35256D
-- 28-pin SOP (450 mil) plastic package: LC35256DM
-- 28-pin TSOP (8
13.4 mm) plastic package:
LC35256DT
Package Dimensions
unit: mm
3012A-DIP28
unit: mm
3187-SOP28D
unit: mm
3221-TSOP28(type-I)
CMOS IC
51398RM (OT) No. 5823-1/8
SANYO: DIP28
[LC35256D]
SANYO: SOP28D
[LC35256DM]
SANYO: TSOP28(type-I)
[LC35256DT]
SANYO Electric Co.,Ltd. Semiconductor Bussiness Headquarters
TOKYO OFFICE Tokyo Bldg., 1-10, 1 Chome, Ueno, Taito-ku, TOKYO, 110-8534 JAPAN
Dual Control Pins: OE and CE
256K (32768-word
8-bit) SRAM
LC35256D-10, LC35256DM, DT-70/10
Ordering number : EN5823
Pin Assignment
No. 5823-2/8
LC35256D-10, LC35256DM, DT-70/10
Block Diagram
Pin Functions
A0 to A14
Address inputs
WE
Read/write control input
OE
Output enable input
CE
Chip enable input
I/O1 to I/O8
Data I/O
V
CC
, GND
Power supply, ground
Address buffer
Address buffer
Input data buffer
Input data
control circuit
Row decoder
Memory cell array
Column
I/O circuit
Output
data
buffer
Column
decoder
No. 5823-3/8
LC35256D-10, LC35256DM, DT-70/10
Function Table
X : H or L
Note
*
: 3.0 V for pulse widths of up to 30 ns.
Note: These parameters are not measured in all units, but rather are only measured in sampled units.
Note
*
: 3.0 V for pulse widths of up to 30 ns.
Note
*
: Reference value at Ta = 25C, V
CC
= 5 V.
Mode
CE
OE
WE
I/O
Supply current
Read cycle
L
L
H
Data output
I
CCA
Write cycle
L
X
L
Data input
I
CCA
Output disable
L
H
H
High-impedance
I
CCA
Unselected
H
X
X
High-impedance
I
CCS
Parameter
Symbol
Conditions
Ratings
Unit
Maximum supply voltage
V
CC
max
7.0
V
Input pin voltage
V
IN
0.3
*
to V
CC
+ 0.3
V
I/O pin voltage
V
I/O
0.3 to V
CC
+ 0.3
V
Operating temperature
Topr
40 to +85
C
Storage temperature
Tstg
55 to +125
C
Specifications
Absolute Maximum Ratings
Parameter
Symbol
Conditions
Ratings
Unit
min
typ
max
I/O pin capacitance
C
I/O
V
I/O
= 0 V
6
10
pF
Input pin capacitance
C
IN
V
IN
= 0 V
6
10
pF
I/O Capacitances
at Ta = 25C, f = 1 MHz
[5-V Operation]
Parameter
Symbol
Conditions
Ratings
Unit
min
typ
max
Supply voltage
V
CC
4.5
5.0
5.5
V
Input voltages
V
IH
2.2
V
CC
+ 0.3
V
V
IL
0.3
*
+0.8
V
DC Allowable Operating Ranges
at Ta = 40 to +85C, V
CC
= 4.5 to 5.5 V
Parameter
Symbol
Conditions
Ratings
Unit
min
typ
*
max
Input leakage current
I
LI
V
IN
= 0 to V
CC
1.0
+1.0
A
Output leakage current
I
LO
V
CE
= V
IH
or V
OE
= V
IH
or V
WE
= V
IL
, V
I/O
= 0 to V
CC
1.0
+1.0
A
High-level output voltage
V
OH
I
OH
= 1.0 mA
2.4
V
Low-level output voltage
V
OL
I
OL
= 2.0 mA
0.4
V
I
CCA2
V
CE
= V
IL
, I
I/O
= 0 mA, V
IN
= V
IH
or V
IL
5.0
mA
Operating
TTL inputs
V
CE
= V
IL
, V
IN
= V
IH
or V
IL
,
min
LC35256DM, DT-70
35
40
mA
current drain
I
CCA3
I
I/O
= 0 mA, Duty 100%
cycle LC35256D, DM, DT-10
25
30
mA
1 s cycle
3.5
6.0
mA
V
CC
0.2 V/
V
CE
V
CC
0.2 V,
Ta
25C
0.01
A
Standby mode
0.2 V inputs
I
CCS1
V
IN
= 0 to V
CC
Ta
60C
1.0
A
current drain
Ta
85C
5.0
A
TTL inputs
I
CCS2
V
CE
= V
IH
, V
IN
= 0 to V
CC
1.0
mA
DC Electrical Characteristics
at Ta = 40 to +85C, V
CC
= 4.5 to 5.5 V
AC Electrical Characteristics
at Ta = 40 to +85C, V
CC
= 4.5 to 5.5 V
No. 5823-4/8
LC35256D-10, LC35256DM, DT-70/10
LC35256D, DM, DT
Parameter
Symbol
-70
*
-10
Unit
min
max
min
max
Read cycle time
t
RC
70
100
ns
Address access time
t
AA
70
100
ns
CE access time
t
CA
70
100
ns
OE access time
t
OA
35
50
ns
Output hold time
t
OH
10
10
ns
CE output enable time
t
COE
10
10
ns
OE output enable time
t
OOE
5
5
ns
CE output disable time
t
COD
30
30
ns
OE output disable time
t
OOD
25
25
ns
Read Cycle
Note
*
: Specification values for the LC35256DM and LC35256DT.
LC35256D, DM, DT
Parameter
Symbol
-70
*
-10
Unit
min
max
min
max
Write cycle time
t
WC
70
100
ns
Address setup time
t
AS
0
0
ns
Write pulse width
t
WP
55
60
ns
CE setup time
t
CW
60
70
ns
Write recovery time
t
WR
0
0
ns
CE write recovery time
t
WR1
0
0
ns
Data setup time
t
DS
35
40
ns
Data hold time
t
DH
0
0
ns
CE data hold time
t
DH1
0
0
ns
WE output enable time
t
WOE
5
5
ns
WE output disable time
t
WOD
30
30
ns
Write Cycle
Note
*
: Specification values for the LC35256DM and LC35256DT.
Note
*
: 2.0 V for pulse widths of up to 30 ns.
[3-V Operation]
Parameter
Symbol
Conditions
Ratings
Unit
min
typ
max
Supply voltage
V
CC
2.7
3.0
3.6
V
Input voltages
V
IH
V
CC
0.2
V
CC
+ 0.3
V
V
IL
0.3
*
+0.2
V
DC Allowable Operating Ranges
at Ta = 40 to +85C, V
CC
= 2.7 to 3.6 V
AC test conditions
Input pulse voltage level
V
IH
= 2.4 V, V
IL
= 0.6 V
Input rise and fall times
5 ns
Input and output timing level
1.5 V
Output load
LC35256DM, DT-70
One TTL gate + 30 pF (Including jig capacitances.)
LC35256D, DM, DT-10
One TTL gate + 100 pF (Including jig capacitances.)
No. 5823-5/8
LC35256D-10, LC35256DM, DT-70/10
Note
*
: Reference value at Ta = 25C, V
CC
= 3 V.
Parameter
Symbol
Conditions
Ratings
Unit
min
typ
*
max
Input leakage current
I
LI
V
IN
= 0 to V
CC
1.0
+1.0
A
Output leakage current
I
LO
V
CE
= V
IH
or V
OE
= V
IH
or V
WE
= V
IL
, V
I/O
= 0 to V
CC
1.0
+1.0
A
High-level output voltage
V
OH
I
OH
= 0.5 mA
V
CC
0.2
V
Low-level output voltage
V
OL
I
OL
= 1.0 mA
0.2
V
Operating
V
CC
0.2 V/
V
CE
= V
IL
, V
IN
= V
IH
or V
IL
,
min
LC35256DM, DT-70
7
10
mA
current drain
0.2 V inputs
I
CCA4
I
I/O
= 0 mA, Duty 100%
cycle LC35256D, DM, DT-10
3
5
mA
1 s cycle
1.5
2.5
mA
Standby mode
V
CC
0.2 V/
V
CE
V
CC
0.2 V,
Ta
25C
0.01
A
current drain
0.2 V inputs
I
CCS1
V
IN
= 0 to V
CC
Ta
60C
0.8
A
Ta
85C
4.0
A
DC Electrical Characteristics
at Ta = 40 to +85C, V
CC
= 2.7 to 3.6 V
AC Electrical Characteristics
at Ta = 40 to +85C, V
CC
= 2.7 to 3.6 V
LC35256D, DM, DT
Parameter
Symbol
-70
*
-10
Unit
min
max
min
max
Read cycle time
t
RC
200
500
ns
Address access time
t
AA
200
500
ns
CE access time
t
CA
200
500
ns
OE access time
t
OA
100
250
ns
Output hold time
t
OH
20
20
ns
CE output enable time
t
COE
20
20
ns
OE output enable time
t
OOE
10
10
ns
CE output disable time
t
COD
60
120
ns
OE output disable time
t
OOD
50
100
ns
Read Cycle
Note
*
: Specification values for the LC35256DM and LC35256DT.
AC test conditions
Input pulse voltage level
V
IH
= V
CC
0.2 V, V
IL
= 0.2 V
Input rise and fall times
10 ns
Input and output timing level
1.5 V
Output load
LC35256DM, DT-70
30 pF (Including jig capacitances.)
LC35256D, DM, DT-10
100 pF (Including jig capacitances.)
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