參數(shù)資料
型號(hào): DS12887
廠商: DALLAS SEMICONDUCTOR
元件分類: Timer or RTC
英文描述: 1 TIMER(S), REAL TIME CLOCK, PDIP24
封裝: DIP-24
文件頁數(shù): 12/19頁
文件大?。?/td> 584K
代理商: DS12887
DS12887
2 of 19
generator, and 114 bytes of nonvolatile static RAM. The real time clock is distinctive in that time–of–day
and memory are maintained even in the absence of power.
OPERATION
The block diagram in Figure 1 shows the pin connections with the major internal functions of the
DS12887. The following paragraphs describe the function of each pin.
BLOCK DIAGRAM DS12887 Figure 1
POWER–DOWN/POWER–UP CONSIDERATIONS
The Real Time Clock function will continue to operate and all of the RAM, time, calendar, and alarm
memory locations remain nonvolatile regardless of the level of the VCC input. When VCC is applied to the
DS12887 and reaches a level of greater than 4.25 volts, the device becomes accessible after 200 ms,
provided that the oscillator is running and the oscillator countdown chain is not in reset (see Register A).
This time period allows the system to stabilize after power is applied. When VCC falls below 4.25 volts,
the chip select input is internally forced to an inactive level regardless of the value of CS at the input pin.
The DS12887 is, therefore, write–protected. When the DS12887 is in a write–protected state, all inputs
are ignored and all outputs are in a high impedance state. When VCC falls below a level of approximately
3 volts, the external VCC supply is switched off and an internal lithium energy source supplies power to
the Real Time Clock and the RAM memory.
SIGNAL DESCRIPTIONS
GND, VCC – DC power is provided to the device on these pins. VCC is the +5 volt input. When 5 volts are
applied within normal limits, the device is fully accessible and data can be written and read. When VCC is
below 4.25 volts typical, reads and writes are inhibited. However, the timekeeping function continues
相關(guān)PDF資料
PDF描述
DS1302S 0 TIMER(S), REAL TIME CLOCK, PDSO8
DS1302N 0 TIMER(S), REAL TIME CLOCK, PDIP8
DS1302SN 0 TIMER(S), REAL TIME CLOCK, PDSO8
DS1302 0 TIMER(S), REAL TIME CLOCK, PDIP8
DS1302Z 0 TIMER(S), REAL TIME CLOCK, PDSO8
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
DS12887+ 功能描述:實(shí)時(shí)時(shí)鐘 RTC 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(shí)間格式:HH:MM:SS RTC 存儲(chǔ)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(fēng)格:Through Hole 封裝 / 箱體:PDIP-8 封裝:Tube
DS12887A 功能描述:實(shí)時(shí)時(shí)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(shí)間格式:HH:MM:SS RTC 存儲(chǔ)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(fēng)格:Through Hole 封裝 / 箱體:PDIP-8 封裝:Tube
DS12887A+ 功能描述:實(shí)時(shí)時(shí)鐘 RTC 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(shí)間格式:HH:MM:SS RTC 存儲(chǔ)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(fēng)格:Through Hole 封裝 / 箱體:PDIP-8 封裝:Tube
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