The AS4C256K16FO is a high-performance 4 megabit CMOS Dynamic Random Access Memory (DRAM) device organized as
262,144 words × 16 bits. The AS4C256K16FO is fabricated with advanced CMOS technology and designed with innovative
design techniques resulting in high speed, extremely low power and wide operating margins at component and system levels.
The AS4C256K16FO features a high-speed page mode operation in which high speed read, write and read-write are performed
on any of the 512
×
16 bits defined by the column address. The asynchronous column address uses an extremely short row
address capture time to ease the system-level timing constraints associated with multiplexed addressing. Output is tri-stated by a
column address strobe (CAS) which acts as an output enable independent of RAS. Very fast CAS to output access time eases
system design.
Refresh on the 512 address combinations of A0–A8 during an 8 ms period is accomplished by performing any of the following:
•
•
•
•
•
RAS-only refresh cycles
Hidden refresh cycles
CAS-before-RAS refresh cycles
Normal read or write cycles
Self-refresh cycles.
*
The AS4C256K16FO is available in standard 40-pin plastic SOJ and 44-pin TSOP II packages compatible with widely available
automated testing and insertion equipment. System level features include single power supply of 5V ± 10% tolerance and direct
interface with TTL logic families.
Logic block diagram
V
CC
GND
Refresh
controller
Column decoder
Sense amp
Data
I/O
buffer
I/O0 to I/O15
RAS
RAS clock
generator
CAS clock
generator
UCAS
LCAS
A0
A1
A2
A3
A4
A5
A6
A7
A8
Addreess buffers
OE
Row decoder
512×512×16
array
(4,194,304)
Substrate
bias generator
WE
WE clock
generator
Recommended operating conditions
Parameter
Supply voltage
Input voltage
Symbol
V
CC
GND
V
IH
V
IL
Min
4.5
0.0
2.4
–1.0
Typ
5.0
0.0
–
–
Max
5.5
0.0
V
CC
+ 1
0.8
Unit
V
V
V
V
* Self-refresh option is available for new generation device only. Contact Alliance for more information.
4/11/01; V.0.9.1
Alliance Semiconductor
P. 2 of 25
AS4C256K16FO
®
Absolute maximum ratings
Parameter
Input voltage
Output voltage
Power supply voltage
Operating temperature
Storage temperature (plastic)
Soldering temperature
×
time
Power dissipation
Short circuit output current
Latch-up current
Symbol
V
IN
V
OUT
V
CC
T
OPR
T
STG
T
SOLDER
P
D
I
OUT
Min
–1.0
–1.0
–1.0
0
–55
–
–
–
200
Max
+7.0
+7.0
+7.0
+70
+150
260
×
10
1
50
–
Unit
V
V
V
°C
°C
°C ×
sec
W
mA
mA
Note: 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 outside those indicated in the operational sections of this specification is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect reliability.
[i=s]This post was last edited by qi777ji on 2019-1-8 09:57[/i] [size=5][color=#ff0000]Look at it as an exchange! I am not selling! Those who need it can disassemble the components, and those who need...
Frequency 1-50HZ adjustable current maximum 1 mA AC output voltage no requirement Add 6 LEDs. Working status: Start once every 90 minutes, AC output works for one minute and rests for one minute, only...
I just signed a contract with Shanghai Huawei. I studied for 4 years for undergraduate and 3 years for master's degree. My major was neither computer nor electronics. I finally entered the industry I ...
introduction
1 The significance of using RTOS on MSP430
It is understandable that it is meaningless to use RTOS on MSP430. Because the hardware resources of MSP430 are limited (for exampl...[Details]
Today, with the increasing integration of functions, mobile phones can also be used as portable media players (PMP), digital cameras, handheld computers (PDAs), and even global positioning systems ...[Details]
introduction
Throughout the history of automotive lighting, power has always played an important role. Initially, cars only needed headlights to see the road in the dark. Later, other light so...[Details]
Introduction
Power subsystems are becoming more and more integrated into the overall system. Power systems have moved from being separate "essential dangerous devices" to being monitorable...[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]
As a simple and practical input device, buttons have been used in various microcontroller application systems and are ubiquitous. However, the buttons used in different practical occasions are also...[Details]
I've been studying dot matrix recently. It looks simple, but it takes a while to master it completely! The 8*8 dot matrix hardware circuit I'm making now is like this. The row is driven by 74HC138 + t...[Details]
Continuity test
A variety of devices need to be checked for continuity, including cable assemblies, printed circuit boards, and connectors to ensure that these components have the expected contin...[Details]
Printed circuit boards ( PCBs
)
are used in most electrical products
. If a PCB has low
insulation resistance
(IR), the performance of the circuits on the PCB will be greatly reduced...[Details]
1. Disadvantages of choosing too high a voltage level
Choosing too high a voltage level will result in too high an investment and a long payback period. As the voltage level increases, the...[Details]
With the rapid development of cities and the improvement of citizens' living standards, the number of various vehicles in cities is growing, and the demand for parking spaces in major commercial an...[Details]
The DisplayPort interface standard is approved by the Video Electronics Standards Association (VESA) to provide an open, scalable standard for the entire industry. The development of DisplayPort ca...[Details]
Electric bicycles have long been a means of transportation for lower-income groups due to their affordability. The largest concentrated expense in the use of electric vehicles is the cost of replac...[Details]
a. Keep the battery clean, wipe off the spilled electrolyte, contaminated dirt and dust in time; keep the poles and terminal clamps clean and in good contact, and apply vaseline or butter to preven...[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]