參數(shù)資料
型號(hào): DS1742-100
廠商: Maxim Integrated Products
文件頁數(shù): 12/17頁
文件大?。?/td> 0K
描述: IC RTC RAM Y2K 5V 100NS 24-EDIP
標(biāo)準(zhǔn)包裝: 14
類型: 時(shí)鐘/日歷
特點(diǎn): 閏年,NVSRAM,Y2K
存儲(chǔ)容量: 2KB
時(shí)間格式: HH:MM:SS(24 小時(shí))
數(shù)據(jù)格式: YY-MM-DD-dd
接口: 并聯(lián)
電源電壓: 4.5 V ~ 5.5 V
工作溫度: 0°C ~ 70°C
安裝類型: 通孔
封裝/外殼: 24-DIP 模塊(0.600",15.24mm)
供應(yīng)商設(shè)備封裝: 24-EDIP
包裝: 管件
DS1742
4 of 17
SETTING THE CLOCK
As shown in Table 2, bit 7 of the Control register is the W (write) bit. Setting the W bit to 1 halts
updates to the DS1742 registers. The user can subsequently load correct date and time values
into all eight registers, followed by a write cycle of 00h to the Control register to clear the W bit
and transfer those new settings into the clock, allowing timekeeping operations to resume from
the new set point.
Again referring to Table 2, bit 6 of the Control register is the R (read) bit. Setting the R bit to 1
halts updates to the DS1742 registers. The user can subsequently read the date and time
values from the eight registers without those contents possibly changing during those I/O
operations. A subsequent write cycle of 00h to the Control register to clear the R bit allows
timekeeping operations to resume from the previous set-point.
The pre-existing contents of the Control register bits 0:5 (Century value) are ignored/unmodified
by a write cycle to Control if either the W or R bits are being set to 1 in that write operation.
The pre-existing contents of the Control register bits 0:5 (Century value) will be modified by a
write cycle to Control if the W bit is being cleared to 0 in that write operation.
The pre-existing contents of the Control register bits 0:5 (Century value) will not be modified by
a write cycle to Control if the R bit is being cleared to 0 in that write operation.
STOPPING AND STARTING THE CLOCK OSCILLATOR
The clock oscillator may be stopped at any time. To increase the shelf life, the oscillator can be
turned off to minimize current drain from the battery. The OSC bit is the MSB (bit 7) of the
seconds registers, see Table 2. Setting it to a 1 stops the oscillator.
FREQUENCY TEST BIT
As shown in Table 2, bit 6 of the day byte is the frequency test bit. When the frequency test bit
is set to logic 1 and the oscillator is running, the LSB of the seconds register will toggle at 512
Hz. When the seconds register is being read, the DQ0 line will toggle at the 512 Hz frequency
as long as conditions for access remain valid (i.e., CE low, OE low, WE high, and address for
seconds register remain valid and stable).
CLOCK ACCURACY
The DS1742 is guaranteed to keep time accuracy to within ±1 minute per month at 25°C. Dallas
Semiconductor calibrates the RTC at the factory using nonvolatile tuning elements. The
DS1742 does not require additional calibration. For this reason, methods of field clock
calibration are not available and not necessary. Clock accuracy is also affected by the electrical
environment and caution should be taken to place the RTC in the lowest level EMI section of
the PCB layout. For additional information, refer to Application Note 58.
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DS1742-100+ 功能描述:實(shí)時(shí)時(shí)鐘 Timekeeping NV 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(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
DS1742-100IND 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
DS1742-100IND+ 功能描述:實(shí)時(shí)時(shí)鐘 Timekeeping NV 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(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
DS1742-70 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
DS1742-70+ 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