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 customized an SDK using PB4.2. The SDK can be used in eVC and works fine, but I can't find an option in VS2005. I downloaded a standard sdk500 from the Internet and installed it, but I can select it...
[size=4][color=#0000ff]Free application is here again! [/color][/size] [align=center][url=http://www.vicorpower.com/zh-cn/dc-dc_converters_board_mount/cool-power_zvs_buck-boost?hmsr=eeWorld&hmpl=2018_...
A serial port interrupt receiving and sending program hopes that after receiving a byte, the serial port will determine whether it is empty (0x00) . If it is empty (0x00), it will return 0xFF through ...
1. Prepare toolsPlease install the following PC software tools in advance:X-CUBE -MCSDK MCSDK or X-CUBE -MCSDK -FUL FUL FULSTM32CubeM STM32CubeM STM32CubeMX (v5.3 or above) and firmware libraryST -LIN...
[i=s] This post was last edited by cl17726 on 2014-3-28 15:43 [/i] Test file:Has been executed [font=华文楷体][size=4][color=#2c2c2c] [/color][/size][/font] [font=华文楷体][size=4][color=#2c2c2c]%!xxd -r [/co...
[size=3][backcolor=rgb(238, 238, 238)][font=Tahoma, Helvetica, SimSun, sans-serif]Recently, I have been suffering from the rip-off of the neighborhood where my home community lives. A door access card...
Traditional broadcasting systems generally need to be operated manually at a fixed time, and can only realize one-way broadcasting with few functions. Traditional bell ringing equipment has a singl...[Details]
1. Circuit composition
The whole circuit consists of two parts:
1. Power saving control circuit
As shown in the figure below. Including delay circuit and drive circuit.
(1) Delay ci...[Details]
1. Introduction
With the growth of parking demand, the scale of parking lots is becoming larger and larger. A lot of research has been done on intelligent parking lots in China, but most of th...[Details]
Converged processors meet scalability requirements
In current embedded system design, solutions based on MCU, DSP, FPGA and ASIC account for more than 90% of the market share. These solutions ...[Details]
When choosing a laptop battery, you should consider several factors, such as power, appearance, and quality.
Regarding power, we often see that a manufacturer uses values such as the number ...[Details]
Power management solutions for today's portable application processors are becoming increasingly integrated. Total power consumption, standby and sleep current consumption affect battery size, bill...[Details]
Instrument stepper motor
The stepper motor is an open-loop control element that converts electrical pulse signals into angular displacement or linear displacement. In the case of non...[Details]
1. With the development of modern industry and the continuous improvement of automation, some medium and large control systems have been greatly facilitated, which not only makes control easier, bu...[Details]
The potentiometer is an adjustable electronic component. The main functions of the potentiometer in the circuit are as follows:
1. Used as a voltage divider
A potentiometer is a continuou...[Details]
Motors are important products that convert electrical energy into mechanical energy to achieve automation, and they are widely used in industrial control, medical electronics, white a...[Details]
To understand how and why OLED power supply affects display image quality, you must first understand OLED display technology and power supply requirements. This article will explain the latest OLED...[Details]
introduction
Incandescent bulbs can emit a variety of light, but in specific applications, only green, red, and yellow light are usually needed - such as traffic lights. If an incand...[Details]
0 Introduction
In order to improve the automation control of shortwave transmitters, so that they can automatically process from far to near, the technicians here use the ICS system to complete the ...[Details]
introduction
When it comes to the production of mobile phone lithium-ion batteries, the first thing that comes to mind is Japan's industrialized mechanical assembly line, NOKIO, MOTOLROLA's st...[Details]
The biggest advantage of Profibus is that it is guaranteed by the stable international standard EN50170 and has been proven to be universal in practical applications. It has been widely used in man...[Details]
Embedded System
京公网安备 11010802033920号
EEWORLD
