参数资料
| 型号： | ADT7468ZEVB |
| 厂商： | ON Semiconductor |
| 文件页数： | 59/81页 |
| 文件大小： | 0K |
| 描述： | BOARD EVAL FOR ADT7468 |
| 标准包装： | 1 |
| 其它名称： | EVAL-ADT7468EB EVAL-ADT7468EB-ND |
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ADT7468
ENHANCING SYSTEM ACOUSTICS
Automatic fan speed control mode reacts instantaneously to
changes in temperature, that is, the PWM duty cycle responds
immediately to temperature change. Any impulses in temp-
erature can cause an impulse in fan noise. For psycho-acoustic
reasons, the ADT7468 can prevent the PWM output from
reacting instantaneously to temperature changes. Enhanced
acoustic mode controls the maximum change in PWM duty
cycle at a given time. The objective is to prevent the fan from
cycling up and down, annoying the user.
ACOUSTIC ENHANCEMENT MODE OVERVIEW
Figure 82 gives a top-level overview of the automatic fan control
circuitry on the ADT7468 and shows where acoustic enhance-
ment fits in. Acoustic enhancement is intended as a postdesign
tweak made by a system or mechanical engineer evaluating best
settings for the system. Having determined the optimal settings
for the thermal solution, the engineer can adjust the system
acoustics. The goal is to implement a system that is acoustically
acceptable without causing user annoyance due to fan cycling. It
is important to realize that although a system might pass an
acoustic noise requirement specification (for example, 36 dB), if
the fan is annoying, it fails the consumer test.
ACOUSTIC
ENHANCEMENT
THERMAL CALIBRATION
100%
PWM
MIN
PWM
CONFIG
RAMP
CONTROL
(ACOUSTIC
ENHANCEMENT)
PWM
GENERATOR
PWM1
REMOTE 2 =
T MIN T RANGE
THERMAL CALIBRATION
0%
100%
PWM
MIN
TACHOMETER 1
MEASUREMENT
PWM
CONFIG
TACH1
CPU FAN SINK
CPU TEMP
RAMP
MUX
CONTROL
(ACOUSTIC
PWM
GENERATOR
PWM2
ENHANCEMENT)
T MIN
T RANGE
0%
PWM
TACHOMETER 2
MEASUREMENT
PWM
TACH2
LOCAL =
VRM TEMP
THERMAL CALIBRATION
100%
MIN
RAMP
CONFIG
FRONT CHASSIS
CONTROL
(ACOUSTIC
ENHANCEMENT)
PWM
GENERATOR
PWM3
T MIN
T RANGE
0%
TACHOMETER 3
AND 4
MEASUREMENT
TACH3
REMOTE 1 =
AMBIENT TEMP
REAR CHASSIS
Figure 82. Acoustic Enhancement Smoothes Fan Speed Variations under Automatic Fan Speed Control
Rev. 3 | Page 59 of 81 | www.onsemi.com
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PDF描述 |
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相关代理商/技术参数 |
参数描述 |
|---|---|
| ADT7470 | 制造商:AD 制造商全称:Analog Devices 功能描述:Temperature Sensor Hub and Fan Controller |
| ADT7470_13 | 制造商:AD 制造商全称:Analog Devices 功能描述:Temperature Sensor Hub and Fan Controller |
| ADT7470ARQ | 制造商:Analog Devices 功能描述:Temp Sensor Digital Serial (I2C) 16-Pin QSOP |
| ADT7470ARQ-REEL | 制造商:Rochester Electronics LLC 功能描述: 制造商:Analog Devices 功能描述: |
| ADT7470ARQ-REEL7 | 制造商:Analog Devices 功能描述:Temp Sensor Digital Serial (I2C) 16-Pin QSOP T/R |
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