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參數(shù)資料
| 型號： | S1230AB-70 |
| 英文描述： | 256k Nonvolatile SRAM |
| 中文描述： | 256k非易失SRAM |
| 文件頁數(shù)： | 2/12頁 |
| 文件大小： | 213K |
| 代理商： | S1230AB-70 |
DS1230Y/AB
2 of 12
DESCRIPTION
The DS1230 256k Nonvolatile SRAMs are 262,144-bit, fully static, nonvolatile SRAMs organized as
32,768 words by 8 bits. Each NV SRAM has a self-contained lithium energy source and control circuitry
which constantly monitors V
CC
for an out-of-tolerance condition. When such a condition occurs, the
lithium energy source is automatically switched on and write protection is unconditionally enabled to
prevent data corruption. DIP-package DS1230 devices can be used in place of existing 32k x 8 static
RAMs directly conforming to the popular bytewide 28-pin DIP standard. The DIP devices also match the
pinout of 28256 EEPROMs, allowing direct substitution while enhancing performance. DS1230 devices
in the Low Profile Module package are specifically designed for surface-mount applications. There is no
limit on the number of write cycles that can be executed and no additional support circuitry is required for
microprocessor interfacing.
READ MODE
The DS1230 devices execute a read cycle whenever
WE
(Write Enable) is inactive (high) and
CE
(Chip
Enable) and
OE
(Output Enable) are active (low). The unique address specified by the 15 address inputs
(A
0
- A
14
) defines which of the 32,768 bytes of data is to be accessed. Valid data will be available to the
eight data output drivers within t
ACC
(Access Time) after the last address input signal is stable, providing
that
CE
and
OE
(Output Enable) access times are also satisfied. If
OE
and
CE
access times are not
satisfied, then data access must be measured from the later-occurring signal (
CE
or
OE
) and the limiting
parameter is either t
CO
for
CE
or t
OE
for
OE
rather than address access.
WRITE MODE
The DS1230 devices execute a write cycle whenever the
WE
and
CE
signals are active (low) after
address inputs are stable. The later-occurring falling edge of
CE
or
WE
will determine the start of the
write cycle. The write cycle is terminated by the earlier rising edge of
CE
or
WE
. All address inputs must
be kept valid throughout the write cycle.
WE
must return to the high state for a minimum recovery time
(t
WR
) before another cycle can be initiated. The
OE
control signal should be kept inactive (high) during
write cycles to avoid bus contention. However, if the output drivers are enabled (
CE
and
OE
active) then
WE
will disable the outputs in t
ODW
from its falling edge.
DATA RETENTION MODE
The DS1230AB provides full functional capability for V
CC
greater than 4.75 volts and write protects by
4.5 volts. The DS1230Y provides full functional capability for V
CC
greater than 4.5 volts and write
protects by 4.25 volts. Data is maintained in the absence of V
CC
without any additional support circuitry.
The nonvolatile static RAMs constantly monitor V
CC
. Should the supply voltage decay, the NV SRAMs
automatically write protect themselves, all inputs become “don’t care,” and all outputs become high-
impedance. As V
CC
falls below approximately 3.0 volts, a power switching circuit connects the lithium
energy source to RAM to retain data. During power-up, when V
CC
rises above approximately 3.0 volts
the power switching circuit connects external V
CC
to RAM and disconnects the lithium energy source.
Normal RAM operation can resume after V
CC
exceeds 4.75 volts for the DS1230AB and 4.5 volts for the
DS1230Y.
FRESHNESS SEAL
Each DS1230 device is shipped from Dallas Semiconductor with its lithium energy source disconnected,
guaranteeing full energy capacity. When V
CC
is first applied at a level greater than 4.25 volts, the lithium
energy source is enabled for battery back-up operation.
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相關代理商/技術參數(shù) |
參數(shù)描述 |
|---|---|
| S1230ABP-70-IND | 制造商:DALLAS 制造商全稱:Dallas Semiconductor 功能描述:256k Nonvolatile SRAM |
| S-1231A | 功能描述:SWITCH ROTARY DIP 16-POS SIDE RoHS:是 類別:開關 >> DIP 系列:S-1000A 特色產品:RDM Series Rotary DIP Switch 標準包裝:70 系列:RDM 電路:十六進制 位置數(shù):16 觸點額定電壓:0.1A @ 42VDC 觸動器類型:用于工具旋轉 觸動器電平:凹槽式 安裝類型:通孔 方向:頂部觸動 可清洗:是 其它名稱:EG4977-5RDMAR16PIT |
| S1234 | 制造商:LAPP/CONTACT CONNECTORS 功能描述:CONNECTOR, STRAIN RELIEF, LIQUID TIGHT, NON METALLIC, NPT-3/4 INCH, GREY, REDUCE |
| S1236 | 制造商:LAPP/CONTACT CONNECTORS 功能描述:SLR 36 SKINTOP W/R GY W/ NUT |
| S1237 | 制造商:未知廠家 制造商全稱:未知廠家 功能描述:TRIANGULAR TYPE |
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