參數(shù)資料
型號: DS1345YL-70IND
廠商: MAXIM INTEGRATED PRODUCTS INC
元件分類: Static RAM
英文描述: 128K X 8 NON-VOLATILE SRAM MODULE, 70 ns, PDSO34
封裝: LOW PROFILE, SMT-34
文件頁數(shù): 7/14頁
文件大?。?/td> 280K
代理商: DS1345YL-70IND
DS1345Y/AB
2 of 12
READ MODE
The DS1345 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 17 address inputs
(A0 – A16) defines which of the 131,072 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 DS1345 devices execute a write cycle whenever the WE and CE signals are in the active (low) state
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 DS1345AB provides full functional capability for VCC greater than 4.75V and write protects by 4.5V.
The DS1345Y provides full functional capability for VCC greater than 4.5V and write protects by 4.25V.
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 2.7V, the power switching circuit connects the lithium energy source to RAM to
retain data. During power-up, when VCC rises above approximately 2.7V, the power switching circuit
connects external VCC to the RAM and disconnects the lithium energy source. Normal RAM operation
can resume after VCC exceeds 4.75V for the DS1345AB and 4.5V for the DS1345Y.
SYSTEM POWER MONITORING
DS1345 devices have the ability to monitor the external VCC power supply. When an out-of-tolerance
power supply condition is detected, the NV SRAMs warn a processor-based system of impending power
failure by asserting RST . On power-up, RST is held active for 200ms nominal to prevent system
operation during power-on transients and to allow tREC to elapse. RST has an open drain output driver.
BATTERY MONITORING
The DS1345 devices automatically perform periodic battery voltage monitoring on a 24-hour time
interval. Such monitoring begins within tREC after VCC rises above VTP and is suspended when power
failure occurs.
After each 24-hour period has elapsed, the battery is connected to an internal 1M
W test resistor for one
second. During this one second, if battery voltage falls below the battery voltage trip point (2.6V), the
battery warning output BW is asserted. Once asserted, BW remains active until the module is replaced.
The battery is still retested after each VCC power-up, however, even if BW is active. If the battery voltage
is found to be higher than 2.6V during such testing, BW is de-asserted and regular 24-hour testing
resumes. BW has an open drain output driver.
相關(guān)PDF資料
PDF描述
DS1350WP-150 512K X 8 NON-VOLATILE SRAM MODULE, 150 ns, DMA34
DS1350YP-100 512K X 8 NON-VOLATILE SRAM MODULE, 100 ns, DMA34
DS1350ABP-100 512K X 8 NON-VOLATILE SRAM MODULE, 100 ns, DMA34
DS1350YP-70 512K X 8 NON-VOLATILE SRAM MODULE, 70 ns, DMA34
DS1350ABP-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
DS1345YL-70-IND 制造商:DALLAS 制造商全稱:Dallas Semiconductor 功能描述:1024K Nonvolatile SRAM with Battery Monitor
DS1345YP-100 功能描述:NVRAM 1024K NV SRAM w/Battery Monitor RoHS:否 制造商:Maxim Integrated 數(shù)據(jù)總線寬度:8 bit 存儲容量:1024 Kbit 組織:128 K x 8 接口類型:Parallel 訪問時間: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
DS1345YP-100+ 功能描述:NVRAM 1024K NV SRAM w/Battery Monitor RoHS:否 制造商:Maxim Integrated 數(shù)據(jù)總線寬度:8 bit 存儲容量:1024 Kbit 組織:128 K x 8 接口類型:Parallel 訪問時間: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
DS1345YP-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)
DS1345YP-70 功能描述:NVRAM 1024K NV SRAM w/Battery Monitor RoHS:否 制造商:Maxim Integrated 數(shù)據(jù)總線寬度:8 bit 存儲容量:1024 Kbit 組織:128 K x 8 接口類型:Parallel 訪問時間: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