CMOS Static RAM
1 Meg (256K x 4-Bit)
Features
x
x
IDT71028
Description
The IDT71028 is a 1,048,576-bit high-speed static RAM orga-
nized as 256K x 4. It is fabricated using IDT’s high-perfomance, high-
reliability CMOS technology. This state-of-the-art technology, com-
bined with innovative circuit design techniques, provides a cost-
effective solution for high-speed memory needs.
The IDT71028 has an output enable pin which operates as fast
as 6ns, with address access times as fast as 12ns. All bidirectional
inputs and outputs of the IDT71028 are TTL-compatible and oper-
ation is from a single 5V supply. Fully static asynchronous circuitry
is used, requiring no clocks or refresh for operation.
The IDT71028 is packaged in a 28-pin 400 mil Plastic SOJ.
x
x
x
x
256K x 4 advanced high-speed CMOS static RAM
Equal access and cycle times
— Commercial and Industrial: 12/15/20ns
One Chip Select plus one Output Enable pin
Bidirectional data inputs and outputs directly
TTL-compatible
Low power consumption via chip deselect
Available in 400 mil Plastic SOJ package.
Functional Block Diagram
A
0
•
•
•
ADDRESS
DECODER
•
•
•
1,048,576-BIT
MEMORY
ARRAY
A
17
I/O
0
–I/O
3
4
4
I/O CONTROL
CS
WE
OE
CONTROL
LOGIC
2966 drw 01
FEBRUARY 2001
1
©2000 Integrated Device Technology, Inc.
DSC-2966/08
IDT71028 CMOS Static RAM
1 Meg (256K x 4-Bit)
Commercial and Industrial Temperature Ranges
Pin Configuration
A
0
A
1
A
2
A
3
A
4
A
5
A
6
A
7
A
8
A
9
A
10
CS
OE
GND
1
28
27
2
3
26
25
4
24
5
23
6
SO28-6
22
7
21
8
9
20
10
19
11
18
17
12
13
16
15
14
V
CC
A
17
A
16
A
15
A
14
A
13
A
12
A
11
NC
I/O
3
I/O
2
I/O
1
I/O
0
WE
Absolute Maximum Ratings
(1)
Symbol
V
TERM
(2)
T
A
T
BIAS
T
STG
P
T
I
OUT
Rating
Terminal Voltage with Respect to GND
Operating Temperature
Temperature Under Bias
Storage Temperature
Power Dissipation
DC Output Current
Value
–0.5 to +7.0
0 to +70
–55 to +125
–55 to +125
1.25
50
Unit
V
o
o
o
C
C
C
W
mA
2966 tbl 02
2966 drw 02
SOJ
Top View
NOTES:
1. Stresses greater than those listed under ABSOLUTE MAXIMUM RATINGS may cause
permanent damage to the device. This is a stress rating only and functional operation
of the device at these or any other conditions above those indicated in the operational
sections of this specification is not implied. Exposure to absolute maximum rating
conditions for extended periods may affect reliability.
2. V
TERM
must not exceed V
CC
+ 0.5V.
Capacitance
Truth Table
CS
L
L
L
H
V
HC
(3)
OE
L
X
H
X
X
H
L
H
X
X
(1,2)
(T
A
= +25°C, f = 1.0MHz, SOJ package)
Symbol
I/O
DATA
OUT
DATA
IN
High-Z
High-Z
High-Z
Function
Read Data
Write Data
Output Disabled
Deselected – Standby (I
SB
)
Deselected – Standby (I
SB1
)
2966 tbl 01
Parameter
(1)
Input Capacitance
I/O Capacitance
Conditions
V
IN
= 3dV
V
OUT
= 3dV
Max.
8
8
Unit
pF
pF
2966 tbl 03
WE
C
IN
C
I/O
NOTE:
1. This parameter is guaranteed by device characterization, but not production tested.
NOTES:
1. H = V
IH
, L = V
IL
, x = Don't care.
2. V
LC
= 0.2V, V
HC
= V
CC
-0.2V.
3. Other inputs
≥V
HC
or
≤V
LC
.
Recommended DC Operating
Conditions
Symbol
V
CC
Parameter
Supply Voltage
Ground
Input High Voltage
Input Low Voltage
Min.
4.5
0
2.2
–0.5
(1)
Typ.
5.0
0
____
____
Max.
5.5
0
V
CC
+0.5
0.8
Unit
V
V
V
V
2966 tbl 04
Recommended Operating
Temperature and Supply Voltage
Grade
Commercial
Industrial
Temperature
0
O
C to +70
O
C
–40
O
C to +85
O
C
V
SS
0V
0V
V
SS
5.0V ± 10%
5.0V ± 10%
2966 tbl 05
GND
V
IH
V
IL
NOTE:
1. V
IL
(min.) = –1.5V for pulse width less than 10ns, once per cycle.
6.42
2
IDT71028 CMOS Static RAM
1 Meg (256K x 4-Bit)
Commercial and Industrial Temperature Ranges
DC Electrical Characteristics
(V
CC
= 5.0V ± 10%, Commercial and Industrial Temperature Ranges)
IDT71028
Symbol
|I
LI
|
|I
LO
|
V
OL
V
OH
Parameter
Input Leakage Current
Output Leakage Current
Output Low Voltage
Output High Voltage
Test Condition
V
CC
= Max., V
IN
= GND to V
CC
V
CC
= Max.,
CS
= V
IH
, V
OUT
= GND to V
CC
I
OL
= 8mA, V
CC
= Min.
I
OH
= –4mA, V
CC
= Min.
Min.
___
___
___
Max.
5
5
0.4
___
Unit
µA
µA
V
V
2966 tbl 06
2.4
DC Electrical Characteristics
(1)
(V
CC
= 5.0V ± 10%, V
LC
= 0.2V, V
HC
= V
CC
– 0.2V)
71028S12
Symbol
I
CC
Parameters
Dynamic Operating Current,
CS
≤
V
IL
, Outputs Open,
V
CC
= Max., f = f
MAX
(2)
Standby Power Supply Current (TTL Level)
CS
≥
V
IH
, Outputs Open,
V
CC
= Max., f=f
MAX
(2)
Full Standby Power Supply Current
(CMOS Level),
CS
≥
V
HC
, Outputs Open,
V
CC
= Max., f = 0
(2)
, V
IN
≤
V
LC
or V
IN
≥
V
HC
Com'l.
155
Ind.
170
71028S15
Com'l.
150
Ind.
165
71028S20
Com'l.
145
Ind.
160
Unit
mA
I
SB
40
40
40
40
40
40
mA
I
SB1
10
10
10
10
10
10
mA
NOTES:
1. All values are maximum guaranteed values.
2. f
MAX
= 1/t
RC
(all address inputs are cycling at f
MAX
)
;
f = 0 means no address input lines are changing.
2966 tbl 07
AC Test Conditions
Input Pulse Levels
Input Rise/Fall Times
Input Timing Reference Levels
Output Reference Levels
AC Test Load
GND to 3.0V
3ns
1.5V
1.5V
See Figures 1 and 2
2966 tbl 08
AC Test Loads
5V
480Ω
DATA
OUT
30pF
255Ω
2966 drw 03
5V
480Ω
DATA
OUT
5pF*
255Ω
2966 drw 04
*Including jig and scope capacitance.
Figure 2. AC Test Load
Figure 1. AC Test Load
6.42
3
(for t
CLZ
, t
OLZ
, t
CHZ
, t
OHZ
, t
OW,
and t
WHZ
)
IDT71028 CMOS Static RAM
1 Meg (256K x 4-Bit)
Commercial and Industrial Temperature Ranges
AC Electrical Characteristics
(V
CC
= 5.0V ± 10%, Commercial and Industrial Temperature Ranges)
71028S12
Symbol
Read Cycle
t
RC
t
AA
t
ACS
t
CLZ
(1)
t
CHZ
(1)
t
OE
t
OLZ
(1)
t
OHZ
(1)
t
OH
t
PU
(1)
t
PD
(1)
Write Cycle
t
WC
t
AW
t
CW
t
AS
t
WP
t
WR
t
DW
t
DH
t
OW
(1)
t
WHZ
(1)
Write Cycle Time
Address Valid to End-of-Write
Chip Select to End-of-Write
Address Set-Up Time
Write Pulse Width
Write Recovery Time
Data Valid to End-of-Write
Data Hold Time
Output Active from End-of-Write
Write Enable to Output in High-Z
12
10
10
0
10
0
7
0
3
0
—
—
—
—
—
—
—
—
—
5
15
12
12
0
12
0
8
0
3
0
—
—
—
—
—
—
—
—
—
5
20
15
15
0
15
0
9
0
4
0
—
—
—
—
—
—
—
—
—
8
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
2966 tbl 09
71028S15
Min.
Max.
71028S20
Min.
Max.
Unit
Parameter
Min.
Max.
Read Cycle Time
Address Access Time
Chip Select Access Time
Chip Select to Output in Low-Z
Chip Deselect to Output in High-Z
Output Enable to Output Valid
Output Enable to Output in Low-Z
Output Disable to Output in High-Z
Output Hold from Address Change
Chip Select to Power-Up Time
Chip Deselect to Power-Down Time
12
—
—
3
0
—
0
0
4
0
—
—
12
12
—
6
6
—
5
—
—
12
15
—
—
3
0
—
0
0
4
0
—
—
15
15
—
7
7
—
5
—
—
15
20
—
—
3
0
—
0
0
4
0
—
—
20
20
—
8
8
—
7
—
—
20
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
NOTE:
1. This parameter guaranteed with the AC load (Figure 2) by device characterization, but is not production tested.
6.42
4
IDT71028 CMOS Static RAM
1 Meg (256K x 4-Bit)
Commercial and Industrial Temperature Ranges
Timing Waveform of Read Cycle No. 1
(1)
t
RC
ADDRESS
t
AA
OE
t
OE
CS
t
OLZ
(5)
(5)
(3)
t
ACS
t
CLZ
DATA
OUT
t
CHZ (5)
t
OHZ (5)
HIGH IMPEDANCE
DATA
OUT
VALID
t
PD
V
CC
SUPPLY I
CC
CURRENT I
SB
t
PU
2966 drw 05
Timing Waveform of Read Cycle No. 2
(1,2,4)
t
RC
ADDRESS
t
AA
t
OH
DATA
OUT
PREVIOUS DATA
OUT
VALID
t
OH
DATA
OUT
VALID
2966 drw 06
NOTES:
1.
WE
is HIGH for Read Cycle.
2. Device is continuously selected,
CS
is LOW.
3. Address must be valid prior to or coincident with the later of
CS
transition LOW; otherwise t
AA
is the limiting parameter.
4.
OE
is LOW.
5. Transition is measured ±200mV from steady state.
6.42
5
Embedded System
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