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參數(shù)資料
| 型號(hào)： | DS1644P-120 |
| 英文描述： | Nonvolatile Timekeeping RAM |
| 中文描述： | 非易失性內(nèi)存時(shí)鐘 |
| 文件頁(yè)數(shù)： | 4/13頁(yè) |
| 文件大?。?/td> | 302K |
| 代理商： | DS1644P-120 |
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DS1644/DS1644P
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SETTING THE CLOCK
The MSB Bit, (B7) of the control register is the write bit. Setting the write bit to a 1, like the read bit,
halts updates to the DS1644 registers. The user can then load them with the correct day, date and time
data in 24-hour BCD format. Resetting the write bit to a 0 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 for the seconds registers. Setting it to
a 1 stops the oscillator.
FREQUENCY TEST BIT
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, and address for seconds register remain valid and stable).
CLOCK ACCURACY (DIP MODULE)
The DS1644 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. 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 please see
application note 58.
CLOCK ACCURACY (POWERCAP MODULE)
The DS1644 and DS9034PCX are each individually tested for accuracy. Once mounted together, the
module will typically keep 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 PCB layout. For additional information please see application note
58.
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| DS1644J | Quad Clock Driver |
| DS1648J | 2-Input Digital Multiplexer |
| DS3644J | 800mA, Low-Voltage, DC-DC Step-Up Converter, Logic-High On - TDFN-10 |
| DS3644N | Low Voltage, 1.2 MHz, Micropower, DC-DC Step-Up Converter, Powersave Operation (medium loads), shutdown battery feedthrough - TSOT23-6 |
| DS3647A | |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| DS1644P120+ | 制造商:DALLAS 制造商全稱:Dallas Semiconductor 功能描述:Nonvolatile Timekeeping RAM |
| DS1644P-120+ | 功能描述:實(shí)時(shí)時(shí)鐘 NV Timekeeping 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 |
| DS1644P-150 | 制造商:Maxim Integrated Products 功能描述: |
| DS1645AB100 | 制造商:未知廠家 制造商全稱:未知廠家 功能描述:IC-1M CMOS NVRAM |
| DS1645AB-100-IND | 制造商:未知廠家 制造商全稱:未知廠家 功能描述:NVRAM (Battery Based) |
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