When VCC is within nominal limits (V<" />
參數資料
型號: DS1643P-70+
廠商: Maxim Integrated Products
文件頁數: 14/17頁
文件大?。?/td> 0K
描述: IC RAM TIMEKEEP NV 70NS 34-PCM
標準包裝: 40
類型: 時鐘/日歷
特點: 閏年,NVSRAM
存儲容量: 8KB
時間格式: HH:MM:SS(24 小時)
數據格式: YY-MM-DD-dd
接口: 并聯
電源電壓: 4.5 V ~ 5.5 V
電壓 - 電源,電池: 3V
工作溫度: 0°C ~ 70°C
安裝類型: 表面貼裝
封裝/外殼: 34-PowerCap? 模塊
供應商設備封裝: 34-PowerCap 模塊
包裝: 管件
DS1643/DS1643P
6 of 17
DATA RETENTION MODE
When VCC is within nominal limits (VCC > 4.5V) the DS1643 can be accessed as described above with
read or write cycles. However, when VCC is below the power-fail point VPF (point at which write
protection occurs) the internal clock registers and RAM are blocked from access. This is accomplished
internally by inhibiting access via the CE signal. At this time the power-on reset output signal ( RST ) will
be driven active low and will remain active until VCC returns to nominal levels. When VCC falls below the
level of the internal battery supply, power input is switched from the VCC pin to the internal battery and
clock activity, RAM, and clock data are maintained from the battery until VCC is returned to nominal
level. The RST signal is an open drain output and requires a pull up. Except for the RST , all control, data,
and address signals must be powered down when VCC is powered down.
BATTERY LONGEVITY
The DS1643 has a lithium power source that is designed to provide energy for clock activity, and clock
and RAM data retention when the VCC supply is not present. The capability of this internal power supply
is sufficient to power the DS1643 continuously for the life of the equipment in which it is installed. For
specification purposes, the life expectancy is 10 years at 25
C with the internal clock oscillator running in
the absence of VCC power. Each DS1643 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
VPF, the lithium energy source is enabled for battery backup operation. Actual life expectancy of the
Ds1643 will be much longer than 10 years since no lithium battery energy is consumed when VCC is
present.
相關PDF資料
PDF描述
DS1644P-120 IC RAM TIMEKEEP NV 120NS 34-PCM
DS1646-120+ IC RAM TIMEKEEP NV 120NS 32-EDIP
DS1647P-120 IC RAM TIMEKEEP NV 120NS 34-PCM
DS1670S IC CTRLR SYSTEM PORTABLE 20-SOIC
DS1672S-3/T&R IC TIMEKEEPER 3V 32-BIT 8-SOIC
相關代理商/技術參數
參數描述
DS1643P-70+ 功能描述:實時時鐘 RoHS:否 制造商:Microchip Technology 功能:Clock, Calendar. Alarm RTC 總線接口:I2C 日期格式:DW:DM:M:Y 時間格式:HH:MM:SS RTC 存儲容量:64 B 電源電壓-最大:5.5 V 電源電壓-最小:1.8 V 最大工作溫度:+ 85 C 最小工作溫度: 安裝風格:Through Hole 封裝 / 箱體:PDIP-8 封裝:Tube
DS1643P-85 制造商:MAXIM 制造商全稱:Maxim Integrated Products 功能描述:Nonvolatile Timekeeping RAMs
DS1643P-85+ 功能描述:實時時鐘 NV Timekeeping RAM RoHS:否 制造商:Microchip Technology 功能:Clock, Calendar. Alarm RTC 總線接口:I2C 日期格式:DW:DM:M:Y 時間格式:HH:MM:SS RTC 存儲容量:64 B 電源電壓-最大:5.5 V 電源電壓-最小:1.8 V 最大工作溫度:+ 85 C 最小工作溫度: 安裝風格:Through Hole 封裝 / 箱體:PDIP-8 封裝:Tube
DS1644 制造商:MAXIM 制造商全稱:Maxim Integrated Products 功能描述:Nonvolatile Timekeeping RAM
DS1644+120 制造商:DALLAS 制造商全稱:Dallas Semiconductor 功能描述:Nonvolatile Timekeeping RAM