參數(shù)資料
型號(hào): DS1250Y-100
廠商: DALLAS SEMICONDUCTOR
元件分類: Static RAM
英文描述: 512K X 8 NON-VOLATILE SRAM MODULE, 100 ns, DIP32
封裝: 0.740 INCH, EXTENDED MODULE, DIP-32
文件頁數(shù): 4/11頁
文件大?。?/td> 217K
代理商: DS1250Y-100
DS1250Y/AB
2 of 11
DESCRIPTION
The DS1250 4096k Nonvolatile SRAMs are 4,194,304-bit, fully static, nonvolatile SRAMs organized as
524,288 words by 8 bits. Each complete NV SRAM has a self-contained lithium energy source and
control circuitry which constantly monitors VCC 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 DS1250 devices can be used in place of existing 512k x
8 static RAMs directly conforming to the popular byte-wide 32-pin DIP standard. DS1250 devices in the
PowerCap Module package are directly surface mountable and are normally paired with a DS9034PC
PowerCap to form a complete Nonvolatile SRAM module. 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 DS1250 executes 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 19 address inputs (A0 -
A18) defines which of the 524,288 bytes of data is to be accessed. Valid data will be available to the eight
data output drivers within tACC (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 tCO for CE or tOE for OE rather than address access.
WRITE MODE
The DS1250 executes 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 (tWR)
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 tODW from its falling edge.
DATA RETENTION MODE
The DS1250AB provides full functional capability for VCC greater than 4.75 volts and write protects by
4.5 volts. The DS1250Y provides full functional capability for VCC greater than 4.5 volts and write
protects by 4.25 volts. Data is maintained in the absence of VCC without any additional support circuitry.
The nonvolatile static RAMs constantly monitor VCC. 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 VCC falls below approximately 3.0 volts, a power switching circuit connects the lithium
energy source to RAM to retain data. During power-up, when VCC rises above approximately 3.0 volts,
the power switching circuit connects external VCC to RAM and disconnects the lithium energy source.
Normal RAM operation can resume after VCC exceeds 4.75 volts for the DS1250AB and 4.5 volts for the
DS1250Y.
FRESHNESS SEAL
Each DS1250 device is shipped from Dallas Semiconductor with its lithium energy source disconnected,
guaranteeing full energy capacity. When VCC is first applied at a level greater than 4.25 volts, the lithium
energy source is enabled for battery back-up operation.
相關(guān)PDF資料
PDF描述
DS1250W-150 512K X 8 NON-VOLATILE SRAM MODULE, 150 ns, DMA32
DS1250WP-150 512K X 8 NON-VOLATILE SRAM MODULE, 150 ns, DMA34
DS1250Y-70 512K X 8 NON-VOLATILE SRAM MODULE, 70 ns, DMA32
DS1250YP-100 512K X 8 NON-VOLATILE SRAM MODULE, 100 ns, DMA34
DS1250YP-70 512K X 8 NON-VOLATILE SRAM MODULE, 70 ns, DMA34
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
DS1250Y-100+ 功能描述:NVRAM 4096K NV SRAM RoHS:否 制造商:Maxim Integrated 數(shù)據(jù)總線寬度:8 bit 存儲(chǔ)容量:1024 Kbit 組織:128 K x 8 接口類型:Parallel 訪問時(shí)間:70 ns 電源電壓-最大:5.5 V 電源電壓-最小:4.5 V 工作電流:85 mA 最大工作溫度:+ 70 C 最小工作溫度:0 C 封裝 / 箱體:EDIP 封裝:Tube
DS1250Y-100IND 功能描述:NVRAM RoHS:否 制造商:Maxim Integrated 數(shù)據(jù)總線寬度:8 bit 存儲(chǔ)容量:1024 Kbit 組織:128 K x 8 接口類型:Parallel 訪問時(shí)間:70 ns 電源電壓-最大:5.5 V 電源電壓-最小:4.5 V 工作電流:85 mA 最大工作溫度:+ 70 C 最小工作溫度:0 C 封裝 / 箱體:EDIP 封裝:Tube
DS1250Y-100-IND 制造商:未知廠家 制造商全稱:未知廠家 功能描述:NVRAM (Battery Based)
DS1250Y-100IND+ 功能描述:NVRAM 4096K NV SRAM RoHS:否 制造商:Maxim Integrated 數(shù)據(jù)總線寬度:8 bit 存儲(chǔ)容量:1024 Kbit 組織:128 K x 8 接口類型:Parallel 訪問時(shí)間:70 ns 電源電壓-最大:5.5 V 電源電壓-最小:4.5 V 工作電流:85 mA 最大工作溫度:+ 70 C 最小工作溫度:0 C 封裝 / 箱體:EDIP 封裝:Tube
DS1250Y-70 功能描述:NVRAM 4096K NV SRAM RoHS:否 制造商:Maxim Integrated 數(shù)據(jù)總線寬度:8 bit 存儲(chǔ)容量:1024 Kbit 組織:128 K x 8 接口類型:Parallel 訪問時(shí)間:70 ns 電源電壓-最大:5.5 V 電源電壓-最小:4.5 V 工作電流:85 mA 最大工作溫度:+ 70 C 最小工作溫度:0 C 封裝 / 箱體:EDIP 封裝:Tube