参数资料
| 型号： | ISL12027IV27AZ |
| 厂商： | Intersil |
| 文件页数： | 8/28页 |
| 文件大小： | 0K |
| 描述： | IC RTC/CALENDAR EEPROM 8-TSSOP |
| 产品培训模块： | Solutions for Industrial Control Applications |
| 标准包装： | 960 |
| 类型： | 时钟/日历 |
| 特点： | 警报器，闰年，监控器，监视计时器 |
| 时间格式： | HH:MM:SS（12/24 小时） |
| 数据格式： | YY-MM-DD-dd |
| 接口： | I²C，2 线串口 |
| 电源电压： | 2.7 V ~ 5.5 V |
| 电压 - 电源，电池： | 1.8 V ~ 5.5 V |
| 工作温度： | -40°C ~ 85°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 8-TSSOP（0.173"，4.40mm 宽） |
| 供应商设备封装： | 8-TSSOP |
| 包装： | 管件 |
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16
FN8232.8
August 12, 2010
Standard Mode Power Switchover
Normal Operating Mode (VDD) to Battery Backup Mode
(VBAT)
To transition from the VDD to VBAT mode, both of the
following conditions must be met:
Condition 1:
VDD < VBAT - VBATHYS
where VBATHYS ≈ 50mV
Condition 2:
VDD < VTRIP
where VTRIP ≈ 2.2V
Battery Backup Mode (VBAT) to Normal Mode (VDD)
The ISL12027 device will switch from the VBAT to VDD mode
when one of the following conditions occurs:
Condition 1:
VDD > VBAT + VBATHYS
where VBATHYS ≈ 50mV
Condition 2:
VDD > VTRIP + VTRIPHYS
where VTRIPHYS ≈ 30mV
There are two discrete situations that are possible when
using Standard Mode: VBAT < VTRIP and VBAT > VTRIP.
These two power control situations are illustrated in
Figures 13 and 14.
OPTION 2 -LEGACY POWER CONTROL MODE
(ISL12027 DEFAULT)
The Legacy Mode follows conditions set in X1226 products.
In this mode, switching from VDD to VBAT is simply done by
comparing the voltages and the device operates from
whichever is the higher voltage. Care should be taken when
changing from Normal to Legacy Mode. If the VBAT voltage is
higher than VDD, then the device will enter battery back up
and unless the battery is disconnected or the voltage
decreases, the device will no longer operate from VDD. If that
is the situation on initial power-up, then I2C communication
may not be possible. For these applications, the ISL12027A
should be used.
To select the Option 2, BSW bit in the Power Register must
be set to “BSW = 1”.
Normal Mode (VDD) to Battery Backup Mode (VBAT)
To transition from the VDD to VBAT mode, the following
conditions must be met:
VDD < VBAT - VBATHYS
Battery Backup Mode (VBAT) to Normal Mode (VDD)
The device will switch from the VBAT to VDD mode when the
following condition occurs:
VDD > VBAT +VBATHYS
The Legacy Mode power control conditions are illustrated in
Figure 15.
Power On Reset
Application of power to the ISL12027 activates a Power On
Reset Circuit that pulls the RESET pin active. This signal
provides several benefits.
It prevents the system microprocessor from starting to
operate with insufficient voltage.
It prevents the processor from operating prior to
stabilization of the oscillator.
It allows time for an FPGA to download its configuration
prior to initialization of the circuit.
It prevents communication to the EEPROM, greatly
reducing the likelihood of data corruption on power-up.
When VDD exceeds the device VRESET threshold value for
typically 250ms the circuit releases RESET, allowing the
system to begin operation. Recommended slew rate is
between 0.2V/ms and 50V/ms.
NOTE: If the VBAT voltage drops below the data sheet
minimum of 1.8V and the VDD power cycles to 0V then back
to VDD voltage, then the RESET output may stay low and the
I2C communications will not operate. The VBAT and VDD
power will need to be cycled to 0V together to allow normal
operation again.
BATTERY BACKUP
MODE
VDD
2.2V
FIGURE 13. BATTERY SWITCHOVER WHEN VBAT < VTRIP
VBAT
VTRIP
1.8V
VBAT + VBATHYS
VBAT - VBATHYS
FIGURE 14. BATTERY SWITCHOVER WHEN VBAT > VTRIP
VTRIP
VBAT
VTRIP + VTRIPHYS
BATTERY BACKUP
MODE
VDD
VTRIP
3.0V
2.2V
VBAT
IN
VOLTAGE
VDD
ON
OFF
FIGURE 15. BATTERY SWITCHOVER IN LEGACY MODE
ISL12027, ISL12027A
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相关代理商/技术参数 |
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| ISL12027IV27AZ-T | 功能描述:实时时钟 REAL TIME CLK/CLNDR W/EEPROM 2 92VSET 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 |
| ISL12027IV27Z | 功能描述:实时时钟 REAL TIME CLK/CLNDR W/EEPROM 2 7VSET 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 |
| ISL12027IV27Z-T | 功能描述:实时时钟 REAL TIME CLK/CLNDR W/EEPROM 2 7VSET 8 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 |
| ISL12027IV30AZ | 功能描述:实时时钟 REAL TIME CLK/CLNDR W/EEPROM 3 09VSET 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 |
| ISL12027IV30AZ-T | 功能描述:实时时钟 REAL TIME CLK/CLNDR W/EEPROM 3 09VSET 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 |
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