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參數(shù)資料
| 型號： | DS14285 |
| 廠商： | DALLAS SEMICONDUCTOR |
| 元件分類： | XO, clock |
| 英文描述： | Real Time Clock with NV RAM Control(帶非易失性RAM控制的實時時鐘) |
| 中文描述： | 1 TIMER(S), REAL TIME CLOCK, PDIP24 |
| 封裝： | DIP-24 |
| 文件頁數(shù)： | 2/23頁 |
| 文件大?。?/td> | 170K |
| 代理商： | DS14285 |
DS14285/DS14287
022798 2/23
PIN DESCRIPTION
AD0–AD7
NC
MOT
CS
AS
R/W
DS
RESET
IRQ
SQW
V
CC
GND
V
CCO
CEI
CEO
X1, X2
V
BAT
– Multiplexed Address/Data Bus
– No Connection
– Bus Type Select (DS14285Q only)
– Chip Select
– Address Strobe
– Read/Write Input
– Data Strobe
– Reset Input
– Interrupt Request Output
– Square Wave Output
– +5 Volt Supply
– Ground
– RAM Power Supply Output
– RAM Chip Enable In
– RAM Chip Enable Out
– 32.768 KHz Crystal Connections
– +3 Volt Battery Input
DESCRIPTION
The DS14285/DS14287 Real Time Clock with NVRAM
Control provides the industry standard DS1287 clock
function with the additional feature of providing nonvola-
tile control for an external SRAM. Functions include a
nonvolatile time–of–day clock, alarm, one–hundred year
calendar, programmable interrupt, square wave genera-
tor, and 114 bytes of nonvolatile static RAM. For the
DS14287 a lithium energy source, quartz crystal, and
write–protection circuitry are contained within a 24–pin
dual in–line package. The DS14285 requires an external
quartz crystal connected to the X1 and X2 pins as well as
an external energy source connected to the V
BAT
pin.
A standard 32,768 KHz quartz crystal can be directly con-
nected to the DS14285 via pins 1 and 2 (X1, X2). The
crystal selected for use should have a specified load
capacitance (C
L
) of 6 pF. For more information on crystal
selection and crystal layout considerations, please con-
sult Application Note 58, “Crystal Considerations with
Dallas Real Time Clocks”.
The DS14285/DS14287 uses its backup energy source
and battery–backup controller to make a standard
CMOS static RAM nonvolatile during power–fail condi-
tions. During power fail, the DS14285/DS14287 auto-
matically write protects the external SRAM and pro-
vides a V
CC
output sourced from its internal battery.
For the DS14287 the internal lithium cell is electrically
isolated from the clock and memory when shipped from
the factory. This isolation is removed after the first
application of V
CC
allowing the lithium cell to provide
data retention to the clock, internal RAM, V
CCO
and
CEO on subsequent power–downs. Care must be
taken after this isolation has been broken to avoid inad-
vertently discharging the lithium cell through the V
CCO
and CEO pins.
OPERATION
The block diagram in Figure 1 shows the pin connections
with
the
major
internal
DS14285/DS14287. The following paragraphs describe
the function of each pin.
functions
of
the
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相關代理商/技術參數(shù) |
參數(shù)描述 |
|---|---|
| DS14285_05 | 制造商:DALLAS 制造商全稱:Dallas Semiconductor 功能描述:Real-Time Clock with NV RAM |
| DS14285+ | 功能描述:實時時鐘 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 時間格式:HH:MM:SS RTC 存儲容量: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: 安裝風格:Through Hole 封裝 / 箱體:PDIP-8 封裝:Tube |
| DS14285-DS14287 | 制造商:DALLAS 制造商全稱:Dallas Semiconductor 功能描述:Real Time Clock with NV RAM Control |
| DS14285N | 功能描述:實時時鐘 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 時間格式:HH:MM:SS RTC 存儲容量: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: 安裝風格:Through Hole 封裝 / 箱體:PDIP-8 封裝:Tube |
| DS14285N+ | 功能描述:實時時鐘 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 時間格式:HH:MM:SS RTC 存儲容量: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: 安裝風格:Through Hole 封裝 / 箱體:PDIP-8 封裝:Tube |
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