参数资料
型号: DS1557P-70IND
厂商: Maxim Integrated Products
文件页数: 10/17页
文件大小: 0K
描述: IC RTC RAM Y2K 5V 70NS 34PCM
标准包装: 1
类型: 时钟/日历
特点: 警报器,闰年,NVSRAM,监视计时器,Y2K
存储容量: 512KB
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
电压 - 电源,电池: 3V
工作温度: -40°C ~ 85°C
安装类型: 表面贴装
封装/外壳: 34-PowerCap? 模块
供应商设备封装: 34-PowerCap 模块
包装: 管件
DS1557 4Meg, Nonvolatile, Y2K-Compliant Timekeeping RAM
2 of 17
ORDERING INFORMATION
PART
TEMP RANGE
VOLTAGE
(V)
PIN-PACKAGE
TOP MARK**
DS1557P-70+
0°C to +70°C
5.0
34 PowerCap*
DS1557P+70
DS1557P-70IND+
-40°C to +85°C
5.0
34 PowerCap*
DS1557P+70 IND
DS1557WP-120+
0°C to +70°C
3.3
34 PowerCap*
DS1557WP+120
DS1557WP-120IND+
-40°C to +85°C
3.3
34 PowerCap*
DS1557WP+120 IND
+ Denotes a lead(Pb)-free/RoHS-compliant package.
*DS9034PCX+ or DS9034I-PCX+ (PowerCap) required. Must be ordered separately.
*An “IND” on the top mark denotes an industrial temperature grade device.
DESCRIPTION
The DS1557 is a full-function, year-2000-compliant (Y2KC), real-time clock/calendar (RTC) with an
RTC alarm, watchdog timer, power-on reset, battery monitor, and 512k x 8 nonvolatile static RAM. User
access to all registers within the DS1557 is accomplished with a byte-wide interface as shown in Figure
1. The RTC registers contain century, year, month, date, day, hours, minutes, and seconds data in 24-hour
BCD format. Corrections for day of month and leap year are made automatically.
The RTC registers are double-buffered into an internal and external set. The user has direct access to the
external set. Clock/calendar updates to the external set of registers can be disabled and enabled to allow
the user to access static data. Assuming the internal oscillator is turned on, the internal set of registers is
continuously updated; this occurs regardless of external registers settings to guarantee that accurate RTC
information is always maintained.
The DS1557 has interrupt (
IRQ/FT) and reset (RST) outputs which can be used to control CPU activity.
The
IRQ/FT interrupt output can be used to generate an external interrupt when the RTC register values
match user programmed alarm values. The interrupt is always available while the device is powered from
the system supply and can be programmed to occur when in the battery-backed state to serve as a system
wakeup. Either the
IRQ/FT or RST outputs can also be used as a CPU watchdog timer, CPU activity is
monitored and an interrupt or reset output will be activated if the correct activity is not detected within
programmed limits. The DS1557 power-on reset can be used to detect a system power down or failure
and hold the CPU in a safe reset state until normal power returns and stabilizes; the
RST output is used
for this function.
The DS1557 also contains its own power-fail circuitry, which automatically deselects the device when the
VCC supply enters an out-of-tolerance condition. This feature provides a high degree of data security
during unpredictable system operation brought on by low VCC levels.
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相关代理商/技术参数
参数描述
DS1557P-70IND+ 功能描述:实时时钟 4M NV RAM Timekeeper 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
DS1557WP-120 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
DS1557WP-120+ 功能描述:实时时钟 4M NV RAM Timekeeper 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
DS1557WP-120IND 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
DS1557WP-120IND+ 功能描述:实时时钟 4M NV RAM Timekeeper 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