PDM41028
1 Megabit Static RAM
256K x 4-Bit
Features
n
1
2
3
4
5
6
7
Description
The PDM41028 is a high-performance CMOS static
RAM organized as 262,144 x 4 bits. Writing to this
device is accomplished when the write enable (WE)
and the chip enable (CE) inputs are both LOW.
Reading is accomplished when WE remains HIGH
and CE and OE are both LOW.
The PDM41028 operates from a single +5V power
supply and all the inputs and outputs are fully TTL-
compatible. The PDM41028 comes in two versions,
the standard power version PDM41028SA and a low
power version the PDM41028LA. The two versions
are functionally the same and only differ in their
power consumption.
The PDM41028 is available in a 28-pin 300-mil SOJ,
and a 28-pin 400-mil SOJ for surface mount
applications.
High speed access times
Com’l: 10, 12 and 15 ns
Ind’l: 12 and 15 ns
Low power operation (typical)
- PDM41028SA
Active: 400 mW
Standby: 150 mW
- PDM41028LA
Active: 350 mW
Standby: 100 mW
Single +5V (
±
10%) power supply
TTL-compatible inputs and outputs
Packages
Plastic SOJ (300 mil) - TSO
Plastic SOJ (400 mil) - SO
n
n
n
n
Functional Block Diagram
A
0
•
•
•
•
•
A
17
Decoder
Memory
Matrix
Addresses
•
•
•
•
•
•
8
9
10
11
I/O
0
I/O
1
I/O
2
I/O
3
• • • • •
Input
Data
Control
Column I/O
CE
WE
OE
12
1
Rev. 2.2 - 4/29/98
PDM41028
Pin Configuration
SOJ
A7
A8
A9
A10
A11
A12
A13
A14
A15
A16
A17
CE
OE
Vss
1
2
3
4
5
6
7
8
9
10
11
12
13
14
28
27
26
25
24
23
22
21
20
19
18
17
16
15
Vcc
A6
A5
A4
A3
A2
A1
A0
NC
I/O3
I/O2
I/O1
I/O0
WE
Pin Description
Name
A17-A0
I/O3-I/O0
OE
WE
CE
NC
V
CC
V
SS
Description
Address Inputs
Data Inputs/Outputs
Output Enable Input
Write Enable Input
Chip Enable Input
No Connect
Power (+5V)
Ground
Truth Table
(1)
OE
X
L
X
H
WE
X
H
L
H
CE
H
L
L
L
I/O
Hi-Z
D
OUT
D
IN
Hi-Z
MODE
Standby
Read
Write
Output Disable
NOTE: 1. H = V
IH
, L = V
IL
, X = DON’T CARE
Absolute Maximum Ratings
(1)
Symbol
V
TERM
T
BIAS
T
STG
P
T
I
OUT
T
j
Rating
Terminal Voltage with Respect to V
SS
Temperature Under Bias
Storage Temperature
Power Dissipation
DC Output Current
Maximum Junction Temperature
(2)
Com’l.
–0.5 to +7.0
–55 to +125
–55 to +125
1.0
50
125
Ind.
–0.5 to +7.0
–65 to +135
–65 to +150
1.0
50
145
Unit
V
°
C
°
C
W
mA
°
C
NOTE: 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. Appropriate thermal calculations should be performed in all cases and specifically for
those where the chosen package has a large thermal resistance (e.g., TSOP). The cal-
culation should be of the form
: T
j
= T
a
+ P *
θ
ja
where T
a
is the ambient temperature, P
is average operating power and
θ
ja
the thermal resistance of the package. For this
product, use the following
θ
ja
values:
SOJ: 76
o
C/W
TSOP: 100
o
C/W
2
Rev. 2.2 - 4/29/98
PDM41028
Recommended DC Operating Conditions
Symbol
V
CC
V
SS
Industrial
Commercial
Parameter
Supply Voltage
Supply Voltage
Ambient Temperature
Ambient Temperature
Min.
4.5
0
–40
0
Typ.
5.0
0
25
25
Max.
5.5
0
85
70
Unit
V
V
°
C
°
C
1
2
3
DC Electrical Characteristics
(V
CC
= 5.0V
±
10%)
PDM41028SA
Symbol
I
LI
I
LO
V
IL
V
IH
V
OL
V
OH
Parameter
Input Leakage Current
Output Leakage Current
Input Low Voltage
Input High Voltage
Output Low Voltage
Output High Voltage
I
OL
= 8 mA, V
CC
= Min.
I
OL
= 10 mA, V
CC
= Min.
I
OH
= –4 mA, V
CC
= Min.
Test Conditions
V
CC
= MAX., V
IN
= V
SS
to V
CC
V
CC
= MAX.,
CE = V
IH
, V
OUT
= V
SS
to V
CC
Com’l/
Ind.
Com’l/
Ind.
Min.
–5
–5
–0.5
(1)
2.2
—
—
2.4
Max.
5
5
0.8
6.0
0.4
0.5
—
PDM41028LA
Min.
–5
–5
–0.5
(1)
2.2
—
—
2.4
Max.
5
5
0.8
6.0
0.4
0.5
—
µ
A
µ
A
V
V
V
V
V
Unit
4
5
6
7
NOTE: 1. V
IL
(min) = –3.0V for pulse width less than 20 ns
Power Supply Characteristics
-10
Symbol Parameter
I
CC
Operating Current
CE = V
IL
,
f = f
MAX
= 1/t
RC
V
CC
= Max.
I
OUT
= 0 mA
I
SB
Standby Current
CE = V
IH
f = f
MAX
= 1/t
RC
V
CC
= Max.
I
SB1
Full Standby Current
CE
≥
V
HC
f=0
V
CC
= Max.,
V
IN
≥
V
CC
– 0.2V or
≤
0.2V
-12
-15
Unit
mA
mA
Power Com’l. Com’l Ind. Com’l Ind.
SA
250
230
240
185
195
LA
230
210
220
165
175
8
9
10
11
12
3
SA
LA
SA
LA
80
75
20
10
70
65
15
10
70
65
25
10
55
50
10
5
55
50
15
10
mA
mA
mA
mA
SHADED AREA = PRELIMINARY DATA
NOTES: All values are maximum guaranteed values.
V
LC
≤
0.2V, V
HC
≥
V
CC
– 0.2V
Rev. 2.2 - 4/29/98
PDM41028
Capacitance
(1)
(T
A
= +25
°
C, f = 1.0 MHz)
Symbol
C
IN
C
OUT
Parameter
Input Capacitance
Output Capacitance
Max.
8
8
Unit
pF
pF
NOTE:1. This parameter is determined by device characterization but is not production tested.
AC Test Conditions
Input pulse levels
Input rise and fall times
Input timing reference levels
Output reference levels
Output load
V
SS
to 3.0V
3 ns
1.5V
1.5V
See Figures 1 and 2
+5V
480Ω
D
OUT
255Ω
30 pF
+5V
480Ω
D
OUT
255Ω
5 pf
Figure 1. Output Load Equivalent
Figure 2. Output Load Equivalent
(for t
LZCE
, t
HZCE
, t
LZWE
, t
HZWE
, t
LZOE
,
t
HZOE
)
Delta tAA - ns
5
4
3
2
1
0
0
Typical Delta tAA vs Capacitive Loading
Figure 4.
30
60
90
120
Additional Lumped Capacitive Loading (pF)
4
Rev. 2.2 - 4/29/98
PDM41028
Read Cycle No. 1
(4, 5)
t
RC
ADDR
1
DATA VALID
t
AA
t
OH
DOUT
PREVIOUS DATA VALID
2
3
Read Cycle
No. 2
(2, 4, 6)
t
RC
ADDR
t
AA
t
ACE
CE
4
t
HZCE
t
LZCE
OE
5
t
HZOE
t
LZOE
D
OUT
DATA VALID
6
7
t
AOE
AC Electrical Characteristics
Description
READ Cycle
READ cycle time
Address access time
Chip enable access time
Output hold from address change
Chip enable to output in low Z
(1,3)
-10
Sym
t
RC
t
AA
t
ACE
t
OH
t
LZCE
t
HZCE
t
PU
t
PD
t
AOE
t
LZOE
t
HZOE
0
0
3
5
(7)
-12
(7)
8
-15
15
ns
15
15
3
5
6
7
0
ns
ns
ns
ns
ns
ns
15
6
0
6
6
ns
ns
ns
ns
Min. Max. Min. Max. Min. Max. Units
10
10
10
3
5
6
0
10
6
0
6
12
6
12
12
12
9
10
11
12
5
Chip disable to output in high Z
(1,2,3)
Chip enable to power up time
(3)
Chip disable to power down time
(3)
Output enable access time
Output enable to output in low Z
(1,3)
Output disable to output in high Z
(1,3)
SHADED AREA = PRELIMINARY DATA
Notes referenced are after Data Retention Table.
Rev. 2.2 - 4/29/98
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