参数资料
型号: DS1554P-70
厂商: MAXIM INTEGRATED PRODUCTS INC
元件分类: Timer or RTC
英文描述: 0 TIMER(S), REAL TIME CLOCK, DMA34
封装: POWERCAP MODULE-34
文件页数: 18/21页
文件大小: 371K
代理商: DS1554P-70
DS1554 256k, Nonvolatile, Y2K-Compliant Timekeeping RAM
6 of 21
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 DS1554 constantly monitors the battery voltage of the internal batter. The Battery Low Flag (BLF)
bit of the Flags Register (B4 of 7FFF0h) is not writeable 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
DS1554 REAL TIME CLOCK, DMA32
DS1556-70 REAL TIME CLOCK, PDMA32
DS1556W-120 REAL TIME CLOCK, DMA32
DS1556 REAL TIME CLOCK, DMA32
DS1556P REAL TIME CLOCK, DMA34
相关代理商/技术参数
参数描述
DS1554P-70+ 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
DS1554P-70IND 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
DS1554P-70IND+ 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
DS1554W 制造商:未知厂家 制造商全称:未知厂家 功能描述:Real-Time Clock
DS1554W-120 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