and eight bidirectional data lines, DQ(7:0). E Device Enable
controls device selection, active, and standby modes. Asserting
E enables the device, causes I
DD
to rise to its active value, and
decodes the 19 address inputs to select one of 524,288 words in
the memory. W controls read and write operations. During a
read cycle, G must be asserted to enable the outputs.
Table 1. Device Operation Truth Table
G
X
1
X
1
0
W
X
0
1
1
E
1
0
0
0
I/O Mode
3-state
Data in
3-state
Data out
Mode
Standby
Write
Read
2
Read
Figure 2. UT9Q512 25ns SRAM Pinout (36)
(For both shielded and unshielded packages)
PIN NAMES
A(18:0)
DQ(7:0)
E
W
G
V
DD
V
SS
Address
Data Input/Output
Enable
Write Enable
Output Enable
Power
Ground
Notes:
1. “X” is defined as a “don’t care” condition.
2. Device active; outputs disabled.
READ CYCLE
A combination of W greater than V
IH
(min) and E less than V
IL
(max) defines a read cycle. Read access time is measured from
the latter of Device Enable, Output Enable, or valid address to
valid data output.
SRAM Read Cycle 1, the Address Access in figure 3a, is
initiated by a change in address inputs while the chip is enabled
with G asserted and W deasserted. Valid data appears on data
outputs DQ(7:0) after the specified t
AVQV
is satisfied. Outputs
remain active throughout the entire cycle. As long as Device
Enable and Output Enable are active, the address inputs may
change at a rate equal to the minimum read cycle time (t
AVAV
).
SRAM read Cycle 2, the Chip Enable - Controlled Access in
figure 3b, is initiated by E going active while G remains asserted,
W remains deasserted, and the addresses remain stable for the
entire cycle. After the specified t
ETQV
is satisfied, the eight-bit
word addressed by A(18:0) is accessed and appears at the data
outputs DQ(7:0).
SRAM read Cycle 3, the Output Enable - Controlled Access in
figure 3c, is initiated by G going active while E is asserted, W
is deasserted, and the addresses are stable. Read access time is
t
GLQV
unless t
AVQV
or t
ETQV
have not been satisfied.
2
WRITE CYCLE
A combination of W less than V
IL
(max) and E less than
V
IL
(max) defines a write cycle. The state of G is a “don’t care”
for a write cycle. The outputs are placed in the high-impedance
state when either G is greater than V
IH
(min), or when W is less
than V
IL
(max).
Write Cycle 1, the Write Enable - Controlled Access in figure
4a, is defined by a write terminated by W going high, with E
still active. The write pulse width is defined by t
WLWH
when the
write is initiated by W, and by t
ETWH
when the write is initiated
by E. Unless the outputs have been previously placed in the high-
impedance state byG, the user must wait t
WLQZ
before applying
data to the nine bidirectional pins DQ(7:0) to avoid bus
contention.
Write Cycle 2, the Chip Enable - Controlled Access in figure
4b, is defined by a write terminated by E going inactive. The
write pulse width is defined by t
WLEF
when the write is initiated
by W, and by t
ETEF
when the write is initiated by the E going
active. For the W initiated write, unless the outputs have been
previously placed in the high-impedance state
by G, the user must wait t
WLQZ
before applying data to the eight
bidirectional pins DQ(7:0) to avoid bus contention.
TYPICAL RADIATION HARDNESS
Table 2. Radiation Hardness
Design Specifications
1
Total Dose
Heavy Ion
Error Rate
2
50
<1E-8
krad(Si)
Errors/Bit-Day
Notes:
1. The SRAM will not latchup during radiation exposure under recommended
operating conditions.
2. 10% worst case particle environment, Geosynchronous orbit, 0.025 mils of
Aluminum.
3
ABSOLUTE MAXIMUM RATINGS
1
(Referenced to V
SS
)
SYMBOL
V
DD
V
I/O
T
STG
P
D
T
J
Θ
JC
I
I
PARAMETER
DC supply voltage
Voltage on any pin
Storage temperature
Maximum power dissipation
Maximum junction temperature
2
Thermal resistance, junction-to-case
3
DC input current
LIMITS
-0.5 to 7.0V
-0.5 to 7.0V
-65 to +150°C
1.0W
+150°C
10°C/W
±
10 mA
Notes:
1. Stresses outside the listed 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 beyond limits indicated in the operational sections of this specification is not recommended. Exposure to absolute maximum rating
conditions for extended periods may affect device reliability and performance.
2. Maximum junction temperature may be increased to +175°C during burn-in and steady-static life.
3. Test per MIL-STD-883, Method 1012.
RECOMMENDED OPERATING CONDITIONS
SYMBOL
V
DD
T
C
PARAMETER
Positive supply voltage
Case temperature range
LIMITS
4.5 to 5.5V
(C) screening: -55° to +125°C
(E) screening: -40° to +125°C
V
IN
DC input voltage
0V to V
DD
4
DC ELECTRICAL CHARACTERISTICS (Pre/Post-Radiation)*
(-55°C to +125°C for (C) screening and -40
o
C to +125
o
C for (W) screening) (V
DD
= 5.0V + 10%)
SYMBOL
V
IH
V
IL
V
OL1
V
OL2
V
OH1
V
OH2
C
IN 1
C
IO 1
I
IN
I
OZ
PARAMETER
High-level input voltage
Low-level input voltage
Low-level output voltage
Low-level output voltage
High-level output voltage
High-level output voltage
Input capacitance
Bidirectional I/O capacitance
Input leakage current
Three-state output leakage current
I
OL
= 8mA, V
DD
=4.5V
I
OL
= 200µA,V
DD
=4.5V
I
OH
= -4mA,V
DD
=4.5V
I
OH
= -200µA,V
DD
=4.5V
ƒ
= 1MHz @ 0V
ƒ
= 1MHz @ 0V
V
IN
= V
DD
and V
SS,
V
DD
= V
DD
(max)
V
O
= V
DD
and V
SS
V
DD
= V
DD
(max)
G = V
DD
(max)
I
OS 2, 3
I
DD
(OP)
Short-circuit output current
V
DD
= V
DD
(max), V
O
= V
DD
V
DD
= V
DD
(max), V
O
= 0V
Supply current operating
@ 1MHz
Inputs: V
IL
= 0.8V,
V
IH
= 2.0V
I
OUT
= 0mA
V
DD
= V
DD
(max)
I
DD1
(OP)
Supply current operating
@40MHz
Inputs: V
IL
= 0.8V,
V
IH
= 2.0V
I
OUT
= 0mA
V
DD
= V
DD
(max)
I
DD2
(SB)
Supply current standby
@0MHz
Inputs: V
IL
= V
SS
I
OUT
= 0mA
E = V
DD
- 0.5
V
DD
= V
DD
(max)
V
IH
= V
DD
- 0.5V
Notes:
* Post-radiation performance guaranteed at 25°C per MIL-STD-883 Method 1019 .
1. Measured only for initial qualification and after process or design changes that could affect input/output capacitance.
2. Supplied as a design limit but not guaranteed or tested.
3. Not more than one output may be shorted at a time for maximum duration of one second.
I have always liked this forum. I have been visiting it frequently since I registered. Yesterday, I saw some strange posts on the homepage, which were spam advertisements. I posted a post in that sect...
After enabling the keep-alive mechanism, each time the network cable is disconnected, it can only be reconnected once, but it won’t work the second time. I don’t know why?...
[size=4][color=darkgreen][b]Leave the Earth's Surface Project 1602 LCD! 430G2553 LCD display. For reference only, if there are any deficiencies, please point them out! [/b][/color][/size][size=3][colo...
Something happened at home and the weather was so hot that I was sweating all day. There was no water when I came up to the water station at night. There have been frequent water outages recently. I a...
If the ultimate form of a car is a silicon-based life form, then in
the field of
intelligent driving
, it has gradually taken on the appearance of a "veteran driver." In
the field of
the ...[Details]
As the number of cars increases, environmental pressures are also increasing. At this time, some people are saying that new energy vehicles are energy-efficient and environmentally friendly, and ar...[Details]
When discussing autonomous driving technology, there are often two extremes: on the one hand, there's the vision of "fully autonomous driving," while on the other, there's concern about potential s...[Details]
introduction
As “energy conservation and emission reduction” has become an indicator of the National Economic Development Outline of the 11th Five-Year Plan, people’s awareness of green enviro...[Details]
In the scorching summer, electric fans are a must-have for cooling down people's homes. However, I believe most people have encountered this situation: the fan is plugged in, the switch is pressed,...[Details]
Tools/Materials
Yitong Chuanglian MODBUS to PROFIBUS Gateway YT-PB-03
Siemens s7-300
This article describes how to configure the YT-PB-03 MODBUS to PROFIBUS gat...[Details]
Plug-in hybrid vehicles (PHEVs) utilize two powertrains. Their pure electric range is typically inferior to that of pure electric vehicles, often reaching less than half that. Currently, mainstream...[Details]
Compiled from semiengineering
The industry is increasingly concerned about power consumption in AI, but there are no simple solutions. This requires a deep understanding of software and ...[Details]
This new standardized, pre-integrated computing platform is designed to accelerate chip development, reduce development costs, and provide scalable software to power the AI-defined car.
...[Details]
Motor potting compound is a high-performance sealing material widely used for motor encapsulation and insulation. It is essential for motor protection and packaging. Its ideal moisture and water re...[Details]
New energy electric vehicles are energy-saving, environmentally friendly, have low operating costs, and enjoy strong support from national policies. With the growth in sales of new energy electric ...[Details]
introduction
In the context of the comprehensive development of the Internet of Things (IoT) technology under the "Perceiving China" initiative, "Perceiving Mines" is a crucial component of Ch...[Details]
introduction
Whether in the automotive entertainment or home theater system markets, consumers continue to demand more channels and speakers, each capable of handling higher audio po...[Details]
Chip architecture licensing company ARM has hired Amazon's AI chip chief Rami Sinno to help advance its plan to develop its own complete chip, people familiar with the matter said, according to Reu...[Details]
introduction
As the concept of "low-carbon travel and green environmental protection" becomes more and more popular, bicycles have become a crucial means of transportation. Currently, urban pu...[Details]
Suggestions & Announcements
京公网安备 11010802033920号
EEWORLD
