参数资料
型号: DS1743P-100
厂商: DALLAS SEMICONDUCTOR
元件分类: Timer or RTC
英文描述: 0 TIMER(S), REAL TIME CLOCK, DMA34
封装: 0.700 INCH, MODULE, POWERCAP-34
文件页数: 10/17页
文件大小: 247K
代理商: DS1743P-100
DS1743/DS1743P
2 of 17
DESCRIPTION
The DS1743 is a full function, year 2000-compliant (Y2KC), real-time clock/calendar (RTC) and 8k x 8
non-volatile static RAM. User access to all registers within the DS1743 is accomplished with a bytewide
interface as shown in Figure 1. The Real Time Clock (RTC) information and control bits reside in the
eight uppermost RAM locations.
The RTC registers contain century, year, month, date, day, hours,
minutes, and seconds data in 24-hour BCD format. Corrections for the day of the month and leap year are
made automatically.
The RTC clock registers are double buffered to avoid access of incorrect data that
can occur during clock update cycles.
The double buffered system also prevents time loss as the
timekeeping countdown continues unabated by access to time register data. The DS1743 also contains its
own power-fail circuitry, which deselects the device when the VCC supply is in an out of tolerance
condition. This feature prevents loss of data from unpredictable system operation brought on by low VCC
as errant access and update cycles are avoided.
PACKAGES
The DS1743 is available in two packages (28-pin DIP and 34-pin PowerCap module). The 28-pin DIP
style module integrates the crystal, lithium energy source, and silicon all in one package. The 34-pin
PowerCap Module Board is designed with contacts for connection to a separate PowerCap (DS9034PCX)
that contains the crystal and battery. This design allows the PowerCap to be mounted on top of the
DS1743P after the completion of the surface mount process. Mounting the PowerCap after the surface
mount process prevents damage to the crystal and battery due to the high temperatures required for solder
reflow. The PowerCap is keyed to prevent reverse insertion. The PowerCap Module Board and PowerCap
are ordered separately and shipped in separate containers.
The part number for the PowerCap is
DS9034PCX.
CLOCK OPERATIONS-READING THE CLOCK
While the double buffered register structure reduces the chance of reading incorrect data, internal updates
to the DS1743 clock registers should be halted before clock data is read to prevent reading of data in
transition. However, halting the internal clock register updating process does not affect clock accuracy.
Updating is halted when a 1 is written into the read bit, bit 6 of the century register, see Table 2. As long
as a 1 remains in that position, updating is halted. After a halt is issued, the registers reflect the count, that
is day, date, and time that was current at the moment the halt command was issued. However, the internal
clock registers of the double-buffered system continue to update so that the clock accuracy is not affected
by the access of data. All of the DS1743 registers are updated simultaneously after the internal clock
register updating process has been re-enabled. Updating is within a second after the read bit is written to
0.
The READ bit must be a zero for a minimum of 500
s to ensure the external registers will be updated.
相关PDF资料
PDF描述
DS1744-70 REAL TIME CLOCK, PDMA28
DS1744WP-120 REAL TIME CLOCK, DMA34
DS1744P-70 0 TIMER(S), REAL TIME CLOCK, DMA28
DS1744W-120 0 TIMER(S), REAL TIME CLOCK, DMA28
DS1744P REAL TIME CLOCK, DMA34
相关代理商/技术参数
参数描述
DS1743P-100+ 功能描述:实时时钟 Timekeeping NV RAM 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
DS1743P-100IND 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
DS1743P-100IND+ 功能描述:实时时钟 Timekeeping NV RAM 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
DS1743P-70 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
DS1743P-70+ 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