参数资料
| 型号： | ADT7468ZEVB |
| 厂商： | ON Semiconductor |
| 文件页数： | 47/81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 |
第1页第2页第3页第4页第5页第6页第7页第8页第9页第10页第11页第12页第13页第14页第15页第16页第17页第18页第19页第20页第21页第22页第23页第24页第25页第26页第27页第28页第29页第30页第31页第32页第33页第34页第35页第36页第37页第38页第39页第40页第41页第42页第43页第44页第45页第46页当前第47页第48页第49页第50页第51页第52页第53页第54页第55页第56页第57页第58页第59页第60页第61页第62页第63页第64页第65页第66页第67页第68页第69页第70页第71页第72页第73页第74页第75页第76页第77页第78页第79页第80页第81页
ADT7468
T RANGE
100%
100%
PWM MAX
PWM MIN
PWM MIN
0%
0%
T MIN
TEMPERATURE
T MIN
TEMPERATURE
Figure 61. PWM MAX Determines Maximum PWM Duty Cycle Below the
THERM Temperature Limit
Programming the PWM MAX Registers
The PWM MAX registers are 8-bit registers that allow the
Figure 62. T RANGE Parameter Affects Cooling Slope
The T RANGE or fan control slope is determined by the following
procedure:
maximum PWM duty cycle for each output to be configured
anywhere from 0% to 100%. This allows the maximum PWM
duty cycle to be set in steps of 0.39%.
The value to be programmed into the PWM MAX register is given
by
Value (decimal) = PWM MAX /0.39
Example 1: For a maximum PWM duty cycle of 50%,
Value (decimal) – 50/0.39 = 128 (decimal)
Value = 128 (decimal) or 80 (hex)
Example 2: For a minimum PWM duty cycle of 75%,
Value (decimal) = 75/0.39 = 85 (decimal)
Value = 192 (decimal) or C0 (hex)
PWM MAX Registers
Reg. 0x38, PWM1 Maximum Duty Cycle = 0xFF (100% default)
Reg. 0x39, PWM2 Maximum Duty Cycle = 0xFF (100% default)
1.
2.
3.
4.
Determine the maximum operating temperature for that
channel (for example, 70°C).
Determine experimentally the fan speed (PWM duty cycle
value) that does not exceed the temperature at the worst-
case operating points. (For example, 70°C is reached when
the fans are running at 50% PWM duty cycle.)
Determine the slope of the required control loop to meet
these requirements.
Using the ADT7468 evaluation software, you can
graphically program and visualize this functionality. Ask
your local Analog Devices representative for details.
100%
50%
33%
0%
Reg. 0x3A, PWM3 Maximum Duty Cycle = 0xFF
(100% default)
See the Note on Fan Speed and PWM Duty Cycle.
STEP 6: T RANGE for Temperature Channels
T RANGE is the range of temperature over which automatic fan
control occurs once the programmed T MIN temperature has
been exceeded. T RANGE is a temperature slope, not an arbitrary
value; that is, a T RANGE of 40°C holds true only for PWM MIN =
33%. If PWM MIN is increased or decreased, the effective T RANGE
30°C
40°C
T MIN
Figure 63. Adjusting PWM MIN Affects T RANGE
T RANGE is implemented as a slope, which means that as PWM MIN
is changed, T RANGE changes, but the actual slope remains the
same. The higher the PWM MIN value, the smaller the effective
T RANGE , that is, the fan reaches full speed (100%) at a lower
temperature.
changes.
Rev. 3 | Page 47 of 81 | www.onsemi.com
相关PDF资料 |
PDF描述 |
|---|---|
| ADT7473ZEVB | BOARD EVALUATION FOR ADT7473 |
| ADT7475EBZEVB | BOARD EVALUATION FOR ADT7475 |
| ADT7476EBZEVB | BOARD EVALUATION FOR ADT7476 |
| ADT7490ZEVB | BOARD EVALUATION FOR ADT7490 |
| ADZS-21262-1-EZEXT | BOARD DAUGHTER FOR ADSP-21262 |
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 |
发布紧急采购，3分钟左右您将得到回复。