DS1265Y/AB
READ MODE
The DS1265 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 20 address inputs
(A 0 - A 19 ) defines which of the 1,048,576 bytes of data is 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 t ACC .
WRITE MODE
The DS1265 devices execute a write cycle whenever 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 DS1265AB provides full functional capability for V CC greater than 4.75 volts and write protects by
4.5 volts. The DS1265Y 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 DS1265AB and 4.5 volts for the
DS1265Y.
FRESHNESS SEAL
Each DS1265 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 V TP , the lithium
energy source is enabled for battery backup operation.
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相关代理商/技术参数
DS1265W 制造商:DALLAS 制造商全称:Dallas Semiconductor 功能描述:3.3V 8Mb Nonvolatile SRAM
DS1265W-100 功能描述:NVRAM 3.3V 8M NV SRAM RoHS:否 制造商:Maxim Integrated 数据总线宽度:8 bit 存储容量:1024 Kbit 组织:128 K x 8 接口类型:Parallel 访问时间:70 ns 电源电压-最大:5.5 V 电源电压-最小:4.5 V 工作电流:85 mA 最大工作温度:+ 70 C 最小工作温度:0 C 封装 / 箱体:EDIP 封装:Tube
DS1265W-100+ 功能描述:NVRAM 3.3V 8M NV SRAM RoHS:否 制造商:Maxim Integrated 数据总线宽度:8 bit 存储容量:1024 Kbit 组织:128 K x 8 接口类型:Parallel 访问时间:70 ns 电源电压-最大:5.5 V 电源电压-最小:4.5 V 工作电流:85 mA 最大工作温度:+ 70 C 最小工作温度:0 C 封装 / 箱体:EDIP 封装:Tube
DS1265W-100IND 功能描述:NVRAM 3.3V 8M NV SRAM RoHS:否 制造商:Maxim Integrated 数据总线宽度:8 bit 存储容量:1024 Kbit 组织:128 K x 8 接口类型:Parallel 访问时间:70 ns 电源电压-最大:5.5 V 电源电压-最小:4.5 V 工作电流:85 mA 最大工作温度:+ 70 C 最小工作温度:0 C 封装 / 箱体:EDIP 封装:Tube
DS1265W-100-IND 制造商:DALLAS 制造商全称:Dallas Semiconductor 功能描述:3.3V 8Mb Nonvolatile SRAM
DS1265W-100IND+ 功能描述:NVRAM 3.3V 8M NV SRAM RoHS:否 制造商:Maxim Integrated 数据总线宽度:8 bit 存储容量:1024 Kbit 组织:128 K x 8 接口类型:Parallel 访问时间:70 ns 电源电压-最大:5.5 V 电源电压-最小:4.5 V 工作电流:85 mA 最大工作温度:+ 70 C 最小工作温度:0 C 封装 / 箱体:EDIP 封装:Tube
DS1265W-150 功能描述:NVRAM 3.3V 8M NV SRAM RoHS:否 制造商:Maxim Integrated 数据总线宽度:8 bit 存储容量:1024 Kbit 组织:128 K x 8 接口类型:Parallel 访问时间:70 ns 电源电压-最大:5.5 V 电源电压-最小:4.5 V 工作电流:85 mA 最大工作温度:+ 70 C 最小工作温度:0 C 封装 / 箱体:EDIP 封装:Tube
DS1265W-150+ 功能描述:NVRAM 3.3V 8M NV SRAM RoHS:否 制造商:Maxim Integrated 数据总线宽度:8 bit 存储容量:1024 Kbit 组织:128 K x 8 接口类型:Parallel 访问时间:70 ns 电源电压-最大:5.5 V 电源电压-最小:4.5 V 工作电流:85 mA 最大工作温度:+ 70 C 最小工作温度:0 C 封装 / 箱体:EDIP 封装:Tube