The device is fully accessible and data can be written and read when V
參數(shù)資料
型號(hào): DS1678S+T&R
廠商: Maxim Integrated Products
文件頁(yè)數(shù): 24/25頁(yè)
文件大小: 0K
描述: IC REAL TIME EVENT REC 8-SOIC
產(chǎn)品培訓(xùn)模塊: Lead (SnPb) Finish for COTS
Obsolescence Mitigation Program
標(biāo)準(zhǔn)包裝: 2,000
類(lèi)型: 時(shí)間事件記錄器
特點(diǎn): 警報(bào)器,閏年,NVSRAM,Y2K
存儲(chǔ)容量: 32B
時(shí)間格式: HH:MM:SS(12/24 小時(shí))
數(shù)據(jù)格式: YY-MM-DD-dd
接口: I²C,2 線串口
電源電壓: 4.5 V ~ 5.5 V
電壓 - 電源,電池: 2.6 V ~ 3.5 V
工作溫度: -40°C ~ 85°C
安裝類(lèi)型: 表面貼裝
封裝/外殼: 8-SOIC(0.209",5.30mm 寬)
供應(yīng)商設(shè)備封裝: 8-SO
包裝: 帶卷 (TR)
DS1678 Real-Time Event Recorder
8 of 25
POWER CONTROL
The device is fully accessible and data can be written and read when VCC is greater than VPF. However,
when VCC falls below V
PF, the internal registers are blocked from any access. The device power is
switched from VCC to VBAT when VCC drops below VBAT. Operation, except for the I
2C interface, is
maintained from the VBAT source until VCC is returned to nominal levels (Table 1). After VCC returns
above VPF, read and write access is allowed.
Table 1. Power Control
SUPPLY
CONDITION
READ/WRITE
ACCESS
POWERED
BY
VCC < VPF, VCC < VBAT
No
VBAT
VCC < VPF, VCC > VBAT
No
VCC
VCC > VPF, VCC > VBAT
Yes
VCC
OSCILLATOR CIRCUIT
The DS1678 uses an external 32.768kHz crystal. The oscillator circuit does not require any external
resistors or capacitors (CL) to operate. Table 2 specifies several crystal parameters for the external crystal,
and the oscillator block in the Block Diagram shows a functional schematic of the oscillator circuit. Using
a crystal with the specified characteristics, the startup time is usually less than one second.
Table 2. Crystal Specifications*
PARAMETER SYMBOL
MIN
TYP
MAX UNITS
Nominal Frequency
fO
32.768
kHz
Series Resistance
ESR
45
k
Load Capacitance
CL
12.5
pF
*
The crystal, traces, and crystal input pins should be isolated from RF generating signals. Refer to
Application Note 58: Crystal Considerations for Dallas Real-Time Clocks
for additional specifications.
CLOCK ACCURACY
The accuracy of the clock is dependent upon the accuracy of the crystal and the accuracy of the match
between the capacitive load of the oscillator circuit and the capacitive load for which the crystal was
trimmed. Additional error is added by crystal frequency drift caused by temperature shifts. External
circuit noise coupled into the oscillator circuit can result in the clock running fast. Figure 1 shows a
typical PC board layout for crystal and oscillator isolation from noise. Refer to Application Note 58:
Crystal Considerations with Dallas Real-Time Clocks for detailed information.
Figure 1. Typical Crystal Layout
LOCAL GROUND PLANE (LAYER 2)
CRYSTAL
X1
X2
GND
相關(guān)PDF資料
PDF描述
DS3905U-020+ IC POT NV TRIPLE 128POS 10-USOP
MS27484T14F37SA CONN PLUG 37POS STRAIGHT W/SCKT
MS27473T20A35SD CONN PLUG 79POS STRAIGHT W/SCKT
AD5160BRJZ100-RL7 IC POT DGTL SPI 256POS SOT23-8
DS1685E-3+T&R IC RTC 3V 64-BIT Y2KC 24-TSSOP
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
DS1679 制造商:未知廠家 制造商全稱:未知廠家 功能描述:
DS1679B 制造商:Maxim from Components Direct 功能描述:THE MAXIM DS1679B IS A LOW-SIDE MOSFET DRIVER. - Rail/Tube 制造商:Maxim 功能描述:The Maxim DS1679B is a Low-Side MOSFET Driver.
DS1679BS 制造商:Rochester Electronics LLC 功能描述: 制造商:Maxim Integrated Products 功能描述:
DS1679J 制造商:NSC 制造商全稱:National Semiconductor 功能描述:Hex TRI-STATEE TTL to MOS Drivers
DS1679J/A+ 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Memory Driver