U621708
128K x 8 SRAM
Features
131072 x 8 bit static CMOS RAM
70 ns Access Time
Common data inputs and
data outputs
Three-state outputs
Typ. operating supply current
70 ns: 15 mA
Standby current < 1 mA at 85°C
TTL/CMOS-compatible
Power supply voltage 5 V
Operating temperature range
0 °C to 70 °C
-40 °C to 85 °C
QS 9000 Quality Standard
ESD protection > 750 V
(MIL STD 883C M3015.7)
Latch-up immunity >100 mA
Package: PDIP32 (600 mil)
SOP32 (450 mil)
TSOP I 32
sTSOP I 32
Description
The U621708 is a static RAM
manufactured using a CMOS pro-
cess technology with the following
operating modes:
- Read
- Standby
- Write
- Data Retention
The memory array is based on a
6-Transistor cell.
The circuit is activated by the rising
edge of E2 (at E1 = L), or the falling
edge of E1 (at E2 = H). The
address and control inputs open
simultaneously. According to the
information of W and G, the data
inputs, or outputs, are active.
During the active state (E1 = L and
E2 = H) each address change
leads to a new Read cycle. In a
Read cycle, the data outputs are
activated by the falling edge of G,
afterwards the data word will be
available at the outputs DQ0-DQ7.
After the address change, the data
outputs go High-Z until the new
information is available. The data
outputs have no preferred state. If
the memory is driven by CMOS
levels in the active state, and if
there is no change of the address,
data input and control signals W or
G, the operating current (I
O
= 0 mA)
drops to the value of the operating
current in the Standby mode. The
Read cycle is finished by the falling
edge of E2 or W, or by the rising
edge of E1, respectively.
Data retention is guaranteed down
to 2 V. With the exception of E1
and E2, all inputs consist of NOR
gates, so that no pull-up/pull-down
resistors are required.
Pin Configuration
Pin Description
n.c.
A16
A14
A12
A7
A6
A5
A4
A3
A2
A1
A0
DQ0
DQ1
DQ2
VSS
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
32
31
30
29
28
27
26
VCC
A15
E2
W
A13
A8
A9
A11
G
A10
E1
DQ7
DQ6
DQ5
DQ4
DQ3
A11
A9
A8
A13
W
E2
A15
VCC
n.c.
A16
A14
A12
A7
A6
A5
A4
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
32
31
30
29
28
27
26
G
A10
E1
DQ7
DQ6
DQ5
DQ4
DQ3
VSS
DQ2
DQ1
DQ0
A0
A1
A2
A3
Signal Name Signal Description
A0 - A16
DQ0 - DQ7
E1
E2
G
W
VCC
VSS
n.c.
Address Inputs
Data In/Out
Chip Enable 1
Chip Enable 2
Output Enable
Write Enable
Power Supply Voltage
Ground
not connected
PDIP
25
SOP
24
23
22
21
20
19
18
17
TSOP
25
sTSOP
24
23
22
21
20
19
18
17
Top View
Top View
September 1, 2004
1
U621708
Characteristics
All voltages are referenced to V
SS
= 0 V (ground).
All characteristics are valid in the power supply voltage range and in the operating temperature range specified.
Dynamic measurements are based on a rise and fall time of
≤
5 ns, measured between 10 % and 90 % of V
I
, as well as
input levels of V
IL
= 0 V and V
IH
= 3 V. The timing reference level of all input and output signals is 1.5 V,
with the exception of the t
dis
-times and t
en
-times, in which cases transition is measured ±200 mV from steady-state voltage.
Absolute Maximum Ratings
a
Power Supply Voltage
Input Voltage
Output Voltage
Power Dissipation
Operating Temperature
Storage Temperature
Output Short-Circuit Current
at V
CC
= 5 V and V
O
= 0 V
c
a
Symbol
V
CC
V
I
V
O
P
D
Min.
-0.5
-0.5
-0.5
-
0
-40
-65
Max.
7
V
CC
+ 0.5
b
V
CC
+ 0.5
b
1
70
85
150
200
Unit
V
V
V
W
°C
°C
mA
C-Type
K-Type
T
a
T
stg
| I
OS
|
b
c
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 condition 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
Maximum voltage is 7 V
Not more than 1 output should be shorted at the same time. Duration of the short circuit should not exceed 30 s.
Recommended
Operating Conditions
Power Supply Voltage
Input Low Voltage
*
Symbol
V
CC
V
IL
V
IH
Conditions
Min.
4.5
-0.3
2.2
Max.
5.5
0.8
V
CC
+ 0.3
Unit
V
V
V
Input High Voltage
d
-2 V at Pulse Width 10 ns
September 1, 2004
3
U621708
Switching Characteristics
Read Cycle
Read Cycle Time
Address Access Time to Data Valid
Chip Enable Access Time to Data Valid
G LOW to Data Valid
E1 HIGH or E2 LOW to Output in High-Z
G HIGH to Output in High-Z
E1 LOW or E2 HIGH to Output in Low-Z
G LOW to Output in Low-Z
Output Hold Time from Address Change
E1 LOW or E2 HIGH to Power-Up Time
E1 HIGH or E2 LOW to Power-Down Time
Symbol
Alt.
t
RC
t
AA
t
ACE
t
OE
t
HZCE
t
HZOE
t
LZCE
t
LZOE
t
OH
t
PU
t
PD
IEC
t
cR
t
a(A)
t
a(E)
t
a(G)
t
dis(E)
t
dis(G)
t
en(E)
t
en(G)
t
v(A)
10
5
10
0
70
Min.
70
Unit
Max.
70
70
70
25
15
15
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
Switching Characteristics
Write Cycle
Write Cycle Time
Write Pulse Width
Write Setup Time
Address Setup Time
Address Valid to End of Write
Chip Enable Setup Time
Pulse Width Chip Enable to End of Write
Data Setup Time
Data Hold Time
Address Hold from End of Write
W LOW to Output in High-Z
G HIGH to Output in High-Z
W HIGH to Output in Low-Z
G LOW to Output in Low-Z
W to Chip Enable Setup Time
September 1, 2004
Symbol
Alt.
t
WC
t
WP
t
WP
t
AS
t
AW
t
CW
t
CW
t
DS
t
DH
t
AH
t
HZWE
t
HZOE
t
LZWE
t
LZOE
t
WE
5
IEC
t
cW
t
w(W)
t
su(W)
t
su(A)
t
su(A-WH)
Min.
70
Unit
Max.
70
35
35
0
35
40
40
25
0
0
20
15
5
5
10
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
t
su(E)
t
w(E)
t
su(D)
t
h(D)
t
h(A)
t
dis(W)
t
dis(G)
t
en(W)
t
en(G)
t
su(W-E)
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