参数资料
型号: DS1554WP-120
厂商: DALLAS SEMICONDUCTOR
元件分类: Timer or RTC
英文描述: 0 TIMER(S), REAL TIME CLOCK
封装: POWERCAP-34
文件页数: 17/21页
文件大小: 284K
代理商: DS1554WP-120
DS1554
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BATTERY LONGEVITY
The DS1554 has a lithium power source that is designed to provide energy for the 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 DS1554 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. Each DS1554 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 DS1554 will be much longer than 10 years since no internal battery energy is
consumed when VCC is present.
INTERNAL BATTERY MONITOR
The DS15543 constantly monitors the battery voltage of the internal batter. The Battery Low Flag (BLF)
bit of the Flags Register (B4 of 7FFF0h) is not writable and should always be a 0 when read. If a 1 is ever
present, an exhausted lithium energy source is indicated and both the contents of the RTC and RAM are
questionable.
POWER-ON RESET
A temperature compensated comparator circuit monitors the level of VCC. When VCC falls to the power
fail trip point, the RST signal (open drain) is pulled low. When VCC returns to nominal levels, the
RST
signal continues to be pulled low for a period of 40 ms to 200 ms. The power-on reset function is
independent of the RTC oscillator and thus is operational whether or not the oscillator is enabled.
CLOCK OPERATIONS
Table 2 and the following paragraphs describe the operation of RTC, alarm, and watchdog functions.
相关PDF资料
PDF描述
DS1554W-120 0 TIMER(S), REAL TIME CLOCK, PDMA32
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DS1554 REAL TIME CLOCK, DMA32
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相关代理商/技术参数
参数描述
DS1554WP-120+ 功能描述:实时时钟 256kB NV RAM Timekeeper RoHS:否 制造商:Microchip Technology 功能:Clock, Calendar. Alarm RTC 总线接口:I2C 日期格式:DW:DM:M:Y 时间格式:HH:MM:SS RTC 存储容量:64 B 电源电压-最大:5.5 V 电源电压-最小:1.8 V 最大工作温度:+ 85 C 最小工作温度: 安装风格:Through Hole 封装 / 箱体:PDIP-8 封装:Tube
DS1554WP-120IND 功能描述:实时时钟 RoHS:否 制造商:Microchip Technology 功能:Clock, Calendar. Alarm RTC 总线接口:I2C 日期格式:DW:DM:M:Y 时间格式:HH:MM:SS RTC 存储容量:64 B 电源电压-最大:5.5 V 电源电压-最小:1.8 V 最大工作温度:+ 85 C 最小工作温度: 安装风格:Through Hole 封装 / 箱体:PDIP-8 封装:Tube
DS1554WP-120IND+ 功能描述:实时时钟 256kB NV RAM Timekeeper RoHS:否 制造商:Microchip Technology 功能:Clock, Calendar. Alarm RTC 总线接口:I2C 日期格式:DW:DM:M:Y 时间格式:HH:MM:SS RTC 存储容量:64 B 电源电压-最大:5.5 V 电源电压-最小:1.8 V 最大工作温度:+ 85 C 最小工作温度: 安装风格:Through Hole 封装 / 箱体:PDIP-8 封装:Tube
DS1554WP-150 制造商:DALLAS 制造商全称:Dallas Semiconductor 功能描述:256K NV Y2KC Timekeeping RAM
DS1556 制造商:DALLAS 制造商全称:Dallas Semiconductor 功能描述:1M, Nonvolatile, Y2K-Compliant Timekeeping RAM