參數(shù)資料
型號: DS1747-70
廠商: MAXIM INTEGRATED PRODUCTS INC
元件分類: Timer or RTC
英文描述: 0 TIMER(S), REAL TIME CLOCK, DMA32
封裝: EDIP MODULE-32
文件頁數(shù): 14/18頁
文件大小: 476K
代理商: DS1747-70
DS1747/DS1747P Y2K-Compliant, Nonvolatile Timekeeping RAMs
5 of 16
Table 1. Truth Table
VCC
CE
OE
WE
MODE
DQ
POWER
VIH
X
Deselect
High-Z
Standby
VIL
X
VIL
Write
Data In
Active
VIL
VIH
Read
Data Out
Active
VCC>VPF
VIL
VIH
Read
High-Z
Active
VSO<VCC<VPF
X
Deselect
High-Z
CMOS Standby
VCC<VSO<VPF
X
Deselect
High-Z
Data-Retention
Mode
SETTING THE CLOCK
As shown in Table 2, bit 7 of the century register is the write bit. Setting the write bit to a one, like the
read bit, halts updates to the DS1747 registers. The user can then load them with the correct day, date
and time data in 24-hour format. Resetting the write bit to a zero then transfers those values to the actual
clock counters and allows normal operation to resume.
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 one 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 512Hz. When the
seconds register is being read, the DQ0 line will toggle at the 512Hz 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 (DIP MODULE)
The DS1747 is guaranteed to keep time accuracy to within
±1 minute per month at +25°C. The RTC is
calibrated at the factory by Dallas Semiconductor using nonvolatile tuning elements, and does not
require additional calibration. For this reason, methods of field clock calibration are not available and
not necessary. The electrical environment also affects the clock accuracy, and caution should be taken to
place the RTC in the lowest-level EMI section of the PC board layout. For additional information, refer
to Application Note 58.
CLOCK ACCURACY (PowerCap MODULE)
The DS1747 and DS9034PCX are each individually tested for accuracy. Once mounted together, the
module typically keeps time accuracy to within
±1.53 minutes per month (35 ppm) at +25°C. 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 PC board layout. For additional information, refer to Application
Note 58.
相關(guān)PDF資料
PDF描述
DS1747W-120 REAL TIME CLOCK, PDMA32
DS1747P-70 REAL TIME CLOCK, DMA34
DS1747WP-120 REAL TIME CLOCK, DMA34
DS1747 REAL TIME CLOCK, DMA32
DS1747P REAL TIME CLOCK, DMA34
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
DS1747-70+ 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
DS1747-70IND 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
DS1747-70IND+ 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
DS1747-70IND-W 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
DS1747-DS1747P 制造商:DALLAS 制造商全稱:Dallas Semiconductor 功能描述:Y2K-Compliant, Nonvolatile Timekeeping RAMs