收藏本站
ADM1031
How Does the Control Loop Work?
The automatic fan speed control loop is shown in
Figure 21.
100
93
MAX
SPIN-UP FOR 2 SECONDS
87
80
73
66
60
53
T RANGE = 5 ? C
T RANGE = 10 ? C
MIN
47
40
33
0 5 10
20
40
T RANGE = 20 ? C
T RANGE = 40 ? C
T RANGE = 80 ? C
60 80
T MIN
T MAX = T MIN + T RANGE
TEMPERATURE ( ? C)
T RANGE = 40 ? C
T MIN T MAX = T MIN + T RANGE
TEMPERATURE
Figure 21. Automatic Fan Speed Control Loop
T MIN is the temperature at which the fan should switch on
and run at minimum speed. The fan only turns on once the
temperature being measured rises above the T MIN value
programmed. The fan spins up for a predetermined time
(default = 2 seconds). See the Fan Spin-Up section for more
details.
T RANGE is the temperature range over which the
ADM1031 automatically adjusts the fan speed. As the
temperature increases beyond T MIN , the PWM_OUT duty
cycle increases accordingly. The T RANGE parameter
actually defines the fan speed vs. temperature slope of the
control loop.
T MAX is the temperature at which the fan is at its
maximum speed. At this temperature, the PWM duty cycle
driving the fan is 100%. T MAX is given by T MIN + T RANGE .
Since this parameter is the sum of the T MIN and T RANGE
parameters, it does not need to be programmed into a register
on-chip.
A hysteresis value of 5 ? C is included in the control loop
to prevent the fan continuously switching on and off if the
temperature is close to T MIN . The fan continues to run until
the temperature drops 5 ? C below T MIN .
Figure 22 shows the different control slopes determined
by the T RANGE value chosen, and programmed into the
ADM1031. T MIN is set to 0 ? C to start all slopes from the
same point. The figure shows how changing the T RANGE
value affects the PWM duty cycle vs. temperature slope.
Figure 22. PWM Duty Cycle vs. Temperature Slope
(T RANGE )
Figure 23 shows how, for a given T RANGE , changing the
T MIN value affects the loop. Increasing the T MIN value
increases the T MAX (temperature at which the fan runs full
speed) value, since T MAX = T MIN + T RANGE . Note, however,
that the PWM duty cycle vs. temperature slope remains
exactly the same. Changing the T MIN value merely shifts the
control slope. The T MIN can be changed in increments of 4 ? C.
100
93
87
80
73
66
60
53
47
40
33
0 20 40 60 80
°
T MIN T MAX = T MIN + T RANGE
TEMPERATURE ( ? C)
Figure 23. Effect of Increasing T MIN Value on
Control Loop
http://onsemi.com
13
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
EVAL-ADM1062TQEBZ BOARD EVALUATION FOR ADM1062TQ
EVAL-ADM1075CEBZ BOARD EVAL FOR ADM1075
EVAL-ADM1087EBZ BOARD EVALUATION FOR ADM1087
EVAL-ADM1166TQEBZ BOARD EVAL FOR ADM1166TQ
EVAL-ADM1168LQEBZ BOARD EVAL FOR ADM1168LQ
EVAL-ADM1170EBZ BOARD EVALUATION FOR ADM1170
EVAL-ADM1171EBZ BOARD EVALUATION FOR ADM1171
EVAL-ADM1172EBZ BOARD EVALUATION FOR ADM1172
相关代理商/技术参数
EVAL-ADM1034EB 制造商:ON Semiconductor 功能描述:EVAL BOARD - Boxed Product (Development Kits)
EVAL-ADM1060EBZ 功能描述:BOARD EVALUATION ADM1060 RoHS:是 类别:编程器，开发系统 >> 评估演示板和套件 系列:- 标准包装:1 系列:PSoC® 主要目的:电源管理，热管理 嵌入式:- 已用 IC / 零件:- 主要属性:- 次要属性:- 已供物品:板，CD，电源
EVAL-ADM1062-69CSZ 功能描述:EVAL BOARD ADM1062 RoHS:是 类别:编程器，开发系统 >> 评估演示板和套件 系列:- 标准包装:1 系列:- 主要目的:电信，线路接口单元（LIU） 嵌入式:- 已用 IC / 零件:IDT82V2081 主要属性:T1/J1/E1 LIU 次要属性:- 已供物品:板，电源，线缆，CD 其它名称:82EBV2081
EVAL-ADM1062LFEB 功能描述:BOARD EVALUATION FOR ADM1062LF RoHS:否 类别:编程器，开发系统 >> 评估演示板和套件 系列:- 标准包装:1 系列:PSoC® 主要目的:电源管理，热管理 嵌入式:- 已用 IC / 零件:- 主要属性:- 次要属性:- 已供物品:板，CD，电源
EVAL-ADM1062LFEBZ 制造商:Analog Devices 功能描述:EVALUATION KIT FOR ADM1062 制造商:Analog Devices 功能描述:EVAL KIT FOR ADM1062 - Bulk
EVAL-ADM1062TQEB 制造商:Analog Devices 功能描述:EVALUATION BOARD I.C. - Bulk
EVAL-ADM1062TQEBZ 功能描述:BOARD EVALUATION FOR ADM1062TQ RoHS:是 类别:编程器，开发系统 >> 评估演示板和套件 系列:- 标准包装:1 系列:- 主要目的:电信，线路接口单元（LIU） 嵌入式:- 已用 IC / 零件:IDT82V2081 主要属性:T1/J1/E1 LIU 次要属性:- 已供物品:板，电源，线缆，CD 其它名称:82EBV2081
EVAL-ADM1063LFEB 制造商:Analog Devices 功能描述:EVALUATION BOARD I.C. - Bulk