收藏本站
ADT7473
control allows the ADT7473/ADT7473 ? 1 to intelligently
adapt the system’s cooling solution for best system
performance or lowest possible system acoustics, depending
on user or design requirements. Use of dynamic T MIN
control alleviates the need to design for worst-case
conditions and significantly reduces system design and
validation time.
Designing for Worst-case Conditions
System design must always allow for worst-case
conditions. In PC design, the worst-case conditions include,
but are not limited to, the following:
Worst-case Altitude
A computer can be operated at different altitudes. The
altitude affects the relative air density, which alters the
effectiveness of the fan cooling solution. For example,
comparing 40 ? C air temperature at 10,000 feet to 20 ? C air
temperature at sea level, relative air density is increased by
40%. This means that the fan can spin 40% slower and make
Worst-case Processor Power Consumption
This data sheet maximum does not necessarily reflect the
true processor power consumption. Designing for
worst-case CPU power consumption can result in a
processor becoming overcooled (generating excess system
noise).
Worst-case Peripheral Power Consumption
The tendency is to design to data sheet maximums for
peripheral components, again overcooling the system.
Worst-case Assembly
Every system is unique because of manufacturing
variations. Heat sinks may be loose fitting or slightly
misaligned. Too much or too little thermal grease might be
used, or variations in application pressure for thermal
interface material could affect the efficiency of the thermal
solution. Accounting for manufacturing variations in every
system is difficult; therefore, the system must be designed
for the worst-case conditions.
T S
q TIMC
T J
less noise at sea level than at 10,000 feet while keeping the
system at the same temperature at both locations.
Worst-case Fan
Due to manufacturing tolerances, fan speeds in RPM are
normally quoted with a tolerance of ? 20%. The designer
needs to assume that the fan RPM can be 20% below
tolerance. This translates to reduced system airflow and
elevated system temperature. Note that fans 20% out of
tolerance can negatively impact system acoustics because
they run faster and generate more noise.
SINK
THERMAL T TIM
INTERFACE
MATERIAL q CTIM
INTEGRATED
HEAT
SPREADER T TIM
T A
HEAT q SA
q TIMS
T C
PROCESSOR
SUBSTRATE q JTIM
EPOXY
THERMAL INTERFACE MATERIAL
Figure 65. Thermal Model
q CS
q CA
q JA
Worst-case Chassis Airflow
The same motherboard can be used in a number of
different chassis configurations. The design of the chassis
and the physical location of fans and components determine
the system thermal characteristics. Moreover, for a given
chassis, the addition of add-in cards, cables, or other system
configuration options can alter the system airflow and
reduce the effectiveness of the system cooling solution. The
cooling solution can also be inadvertently altered by the end
user. (For example, placing a computer against a wall can
block the air ducts and reduce system airflow.)
Although a design usually accounts for worst-case
conditions in all these cases, the actual system is almost
never operated at worst-case conditions. The alternative to
designing for the worst case is to use the dynamic T MIN
control function.
Dynamic T MIN Control Overview
Dynamic T MIN control mode builds on the basic
automatic fan control loop by adjusting the T MIN value
based on system performance and measured temperature.
This is important because, instead of designing for the worst
VENTS
I/O CARDS
FAN
POWER
SUPPLY
VENTS
I/O CARDS
FAN
POWER
SUPPLY
case, the system thermals can be defined as operating zones.
The ADT7473/ADT7473 ? 1 can self-adjust its fan control
loop to maintain either an operating zone temperature or a
system target temperature. For example, it can be specified
that the ambient temperature in a system should be
GOOD CPU AIRFLOW
FAN
CPU
DRIVE
BAYS
POOR CPU
AIRFLOW
CPU
DRIVE
BAYS
maintained at 50 ? C. If the temperature is below 50 ? C, the
fans might not need to run, or might run very slowly. If the
temperature is higher than 50 ? C, the fans need to throttle up.
The challenge presented by any thermal design is finding
VENTS
GOOD VENTING = GOOD AIR POOR VENTING = POOR AIR
EXCHANGE EXCHANGE
Figure 64. Chassis Airflow Issues
the right settings to suit the system’s fan control solution.
This can involve designing for the worst case, followed by
weeks of system thermal characterization, and finally fan
acoustic optimization (for psycho-acoustic reasons).
http://onsemi.com
43
发布紧急采购，3分钟左右您将得到回复。

采购需求

(若只采购一条型号，填写一行即可)

发布成功！您可以继续发布采购。也可以进入我的后台，查看报价

发布成功！您可以继续发布采购。也可以进入我的后台，查看报价

*型号 *数量 厂商 批号 封装
添加更多采购

我的联系方式

*
*
*
相关PDF资料
ADT7475EBZEVB BOARD EVALUATION FOR ADT7475
ADT7476EBZEVB BOARD EVALUATION FOR ADT7476
ADT7490ZEVB BOARD EVALUATION FOR ADT7490
ADZS-21262-1-EZEXT BOARD DAUGHTER FOR ADSP-21262
ADZS-BF-EZEXT-1 BOARD DAUGHTER ADSP-BF533/561KIT
ADZS-BFAV-EZEXT BOARD DAUGHT ADSP-BF533,37,61KIT
ADZS-BFSHUSB-EZEXT BOARD DAUGHTER EZ EXTENDER
ADZS-BRKOUT-EX3 ADZS-BRKOUT-EX3
相关代理商/技术参数
ADT7475 制造商:ONSEMI 制造商全称:ON Semiconductor 功能描述:dBCOOL Remote Thermal Monitor and Fan Controller
ADT7475_1110 制造商:ONSEMI 制造商全称:ON Semiconductor 功能描述:dbCOOL Remote Thermal Monitor and Fan Controller
ADT7475ARQZ 功能描述:马达/运动/点火控制器和驱动器 MLTCH TDM FAN CTRLR RoHS:否 制造商:STMicroelectronics 产品:Stepper Motor Controllers / Drivers 类型:2 Phase Stepper Motor Driver 工作电源电压:8 V to 45 V 电源电流:0.5 mA 工作温度:- 25 C to + 125 C 安装风格:SMD/SMT 封装 / 箱体:HTSSOP-28 封装:Tube
ADT7475ARQZ-REEL 功能描述:板上安装温度传感器 MULTICH TDM FAN CTRL RoHS:否 制造商:Omron Electronics 输出类型:Digital 配置: 准确性:+/- 1.5 C, +/- 3 C 温度阈值: 数字输出 - 总线接口:2-Wire, I2C, SMBus 电源电压-最大:5.5 V 电源电压-最小:4.5 V 最大工作温度:+ 50 C 最小工作温度:0 C 关闭: 安装风格: 封装 / 箱体: 设备功能:Temperature and Humidity Sensor
ADT7475ARQZ-REEL7 功能描述:IC REMOTE THERMAL CTRLR 16QSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 热管理 系列:dBCool® 标准包装:1 系列:- 功能:温度监控系统（传感器） 传感器类型:内部和外部 感应温度:-40°C ~ 125°C，外部传感器 精确度:±2.5°C 本地（最大值），±5°C 远程（最大值） 拓扑:ADC，比较器，寄存器库 输出类型:2 线 SMBus? 输出警报:无 输出风扇:无 电源电压:2.7 V ~ 5.5 V 工作温度:-40°C ~ 125°C 安装类型:表面贴装 封装/外壳:SOT-23-8 供应商设备封装:SOT-23-8 包装:Digi-Reel® 其它名称:296-22675-6
ADT7475ARQZ-RL7 功能描述:板上安装温度传感器 MLTCH TDM FAN CTRLR RoHS:否 制造商:Omron Electronics 输出类型:Digital 配置: 准确性:+/- 1.5 C, +/- 3 C 温度阈值: 数字输出 - 总线接口:2-Wire, I2C, SMBus 电源电压-最大:5.5 V 电源电压-最小:4.5 V 最大工作温度:+ 50 C 最小工作温度:0 C 关闭: 安装风格: 封装 / 箱体: 设备功能:Temperature and Humidity Sensor
ADT7475EBZEVB 功能描述:BOARD EVALUATION FOR ADT7475 RoHS:否 类别:编程器，开发系统 >> 过时/停产零件编号 系列:dBCool® 标准包装:1 系列:- 传感器类型:CMOS 成像，彩色（RGB） 传感范围:WVGA 接口:I²C 灵敏度:60 fps 电源电压:5.7 V ~ 6.3 V 嵌入式:否 已供物品:成像器板 已用 IC / 零件:KAC-00401 相关产品:4H2099-ND - SENSOR IMAGE WVGA COLOR 48-PQFP4H2094-ND - SENSOR IMAGE WVGA MONO 48-PQFP
ADT7476 制造商:AD 制造商全称:Analog Devices 功能描述:dBCool Remote Thermal Controller and Voltage Monitor