参数资料
型号: DS1744-70+
厂商: Maxim Integrated Products
文件页数: 13/16页
文件大小: 0K
描述: IC RTC RAM Y2K 5V 70NS 28-EDIP
产品培训模块: Lead (SnPb) Finish for COTS
Obsolescence Mitigation Program
标准包装: 12
类型: 时钟/日历
特点: 闰年,NVSRAM,Y2K
存储容量: 32KB
时间格式: HH:MM:SS(24 小时)
数据格式: YY-MM-DD-dd
接口: 并联
电源电压: 4.5 V ~ 5.5 V
工作温度: 0°C ~ 70°C
安装类型: 通孔
封装/外壳: 28-DIP 模块(0.600",15.24mm)
供应商设备封装: 28-EDIP
包装: 管件
产品目录页面: 1434 (CN2011-ZH PDF)
DS1744/DS1744P Y2K-Compliant, Nonvolatile Timekeeping RAMs
6 of 16
CLOCK ACCURACY (PowerCap MODULE)
The DS1744 and DS9034PCX are individually tested for accuracy. Once mounted together, the module
typically keeps time accuracy to within ±1.53 minutes per month (35ppm) 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:
Crystal Considerations with Maxim Real-Time Clocks.
Table 2. Register Map
ADDRESS
DATA
FUNCTION RANGE
B7
B6
B5
B4
B3
B2
B1
B0
7FFF
10 Year
Year
00-99
7FFE
X
10
Month
01-12
7FFD
X
10 Date
Date
01-31
7FFC
BF
FT
X
Day
01-07
7FFB
X
10 Hour
Hour
00-23
7FFA
X
10 Minutes
Minutes
00-59
7FF9
OSC
10 Seconds
Seconds
00-59
7FF8
W
R
10 Century
Century
00-39
OSC
= Stop Bit
R = Read Bit
FT = Frequency Test
W = Write Bit
X = See Note
BF = Battery Flag
Note: All indicated “X” bits are not used but must be set to a “0” during write cycle to ensure proper clock operation.
RETRIEVING DATA FROM RAM OR CLOCK
The DS1744 is in the read mode whenever OE (output enable) is low, WE (write enable) is high, and
CE (chip enable) is low. The device architecture allows ripple-through access to any of the address
locations in the NV SRAM. Valid data is available at the DQ pins within tAA after the last address input is
stable, providing that the CE and OE access times and states are satisfied. If CE or OE access times and
states are not met, valid data is available at the latter of chip-enable access (tCEA) or at output-enable access
time (tOEA). The state of the DQ pins is controlled by CE and OE . If the outputs are activated before tAA,
the data lines are driven to an intermediate state until tAA. If the address inputs are changed while CE and
OE remain valid, output data remains valid for output-data hold time (tOH) but then goes indeterminate
until the next address access.
WRITING DATA TO RAM OR CLOCK
The DS1744 is in the write mode whenever WE and CE are in their active state. The start of a write is
referenced to the latter occurring transition of WE or CE . The addresses must be held valid throughout
the cycle. CE or WE must return inactive for a minimum of tWR prior to the initiation of another read or
write cycle. Data in must be valid tDS prior to the end of write and remain valid for tDH afterward. In a
typical application, the OE signal is high during a write cycle. However, OE can be active provided that
care is taken with the data bus to avoid bus contention. If OE is low prior to WE transitioning low, the
data bus can become active with read data defined by the address inputs. A low transition on WE then
disables the output tWEZ after WE goes active.
相关PDF资料
PDF描述
DS1744WP-120+ IC RTC RAM Y2K 3.3V 120NS 34-PCM
VI-B21-MY-F2 CONVERTER MOD DC/DC 12V 50W
VI-B21-MY-F1 CONVERTER MOD DC/DC 12V 50W
VI-23Z-MY-F3 CONVERTER MOD DC/DC 2V 20W
DS1557WP-120+ IC RTC RAM Y2K 3.3V 120NS 34PCM
相关代理商/技术参数
参数描述
DS1744-70+ 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
DS1744-70IND 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
DS1744-70IND/C01 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
DS1744-70IND+ 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
DS1744P 制造商:DALLAS 制造商全称:Dallas Semiconductor 功能描述:Y2K-Compliant, Nonvolatile Timekeeping RAMs