參數(shù)資料
型號： ADT7460
廠商： Analog Devices, Inc.
英文描述： dB COOL?? Remote Thermal Controller and Fan Controller
中文描述： 分貝很酷吧？？遠程熱控制器和風扇控制器
文件頁數(shù)： 25/48頁
文件大小： 695K
代理商： ADT7460
REV. 0
ADT7460
–25–
ADT7460
FAN SPEED
COUNTER
TACH
TACH
OUTPUT
V
CC
ZD1
*
*
CHOOSE ZD1 VOLTAGE APPROX 0.8 V
CC
12V
PULL-UP
4.7k
TYP
Figure 35b. Fan with TACH Pull-Up to Voltage
> 5 V, e.g., 12 V, Clamped with Zener Diode
If the fan has a strong pull-up (less than 1 k
) to 12 V or a
totem-pole output, then a series resistor can be added to limit the
Zener current, as shown in Figure 35c. Alternatively, a resistive
attenuator may be used, as shown in Figure 35d.
R1 and R2 should be chosen such that:
2
2
1
2
5
V
V
<
×
+
+
<
V
R
R
R
R
PULLUP
PULLUP
/(
)
The fan inputs have an input resistance of nominally 160 k
to
ground, so this should be taken into account when calculating
resistor values.
With a pull-up voltage of 12 V and pull-up resistor less than 1 k
,
suitable values for R1 and R2 would be 100 k
and 47 k
. This
will give a high input voltage of 3.83 V.
5V OR 12V
ADT7460
FAN SPEED
COUNTER
TACH
TACH
OUTPUT
PULL-UP TYP
<1k
OR
TOTEM POLE
V
CC
FAN
ZD1
ZENER
*
*
CHOOSE ZD1 VOLTAGE APPROX 0.8 V
CC
R1
10k
Figure 35c. Fan with Strong TACH Pull-Up to
> V
CC
or Totem-Pole Output, Clamped with Zener
and Resistor
12V
ADT7460
FAN SPEED
COUNTER
TACH
TACH
OUTPUT
<1k
V
CC
R2
*
*
SEE TEXT
R1
*
Figure 35d. Fan with Strong TACH Pull-Up to
> V
CC
or Totem-Pole Output, Attenuated with R1/R2
Fan Speed Measurement
The fan counter does not count the fan TACH output pulses
directly because the fan speed may be less than 1000 RPM and
it would take several seconds to accumulate a reasonably large
and accurate count. Instead, the period of the fan revolution is
measured by gating an on-chip 90 kHz oscillator
into the input of
a 16-bit counter for N periods of the fan TACH
output (Figure 36),
so the accumulated count is actually pro
portional to the fan
tachometer period and inversely
proportional to the fan speed.
1
2
3
4
CLOCK
PWM
TACH
Figure 36. Fan Speed Measurement
N, the number of pulses counted, is determined by the settings
of Register 0x7B (Fan Pulses Per Revolution Register). This
register contains two bits for each fan, allowing one, two
(default), three, or four TACH pulses to be counted.
Fan Speed Measurement Registers
The Fan Tachometer Readings are 16-bit values consisting of a
2-byte read from the ADT7460.
Reg. 0x28
TACH1 Low Byte
= 0x00 default
Reg. 0x29
TACH1 High Byte
= 0x00 default
Reg. 0x2A
TACH2 Low Byte
= 0x00 default
Reg. 0x2B
TACH2 High Byte
= 0x00 default
Reg. 0x2C
TACH3 Low Byte
= 0x00 default
Reg. 0x2D
TACH3 High Byte
= 0x00 default
Reg. 0x2E
TACH4 Low Byte
= 0x00 default
Reg. 0x2F
TACH4 High Byte
= 0x00 default
Reading Fan Speed from the ADT7460
If fan speeds are being measured, this involves a 2-register read
for each measurement. The low byte should be read first. This
causes the high byte to be frozen until both High and Low Byte
registers have been read from. This prevents erroneous TACH
readings.
The Fan Tachometer Reading registers report back the number
of 11.11
μ
s period clocks (90 kHz oscillator) gated to the fan
speed counter, from the rising edge of the first fan TACH pulse
to the rising edge of the third fan TACH pulse (assuming two
pulses per revolution are being counted). Since the device is
essentially measuring the fan TACH period, the higher the
count value the slower the fan is actually running. A 16-bit Fan
Tachometer reading of 0xFFFF indicates either that the fan has
stalled or is running very slowly (< 100 RPM).
HIGH LIMIT: > COMPARISON PERFORMED
Since the actual fan TACH period is being measured, exceeding
a Fan TACH Limit by 1 will set the appropriate Status bit and
can be used to generate an
SMBALERT
.
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PDF描述
ADT7460ARQ dB COOL?? Remote Thermal Controller and Fan Controller
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相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
ADT7460ARQ 功能描述:IC REMOTE THRML/FAN CTRLR 16QSOP RoHS:否 類別:集成電路 (IC) >> PMIC - 熱管理 系列:dBCool® 標準包裝:1 系列:- 功能:溫度監(jiān)控系統(tǒng)（傳感器） 傳感器類型:內(nèi)部和外部 感應(yīng)溫度:-40°C ~ 125°C，外部傳感器 精確度:±2.5°C 本地（最大值），±5°C 遠程（最大值） 拓撲:ADC，比較器，寄存器庫 輸出類型:2 線 SMBus? 輸出警報:無 輸出風扇:無 電源電壓:2.7 V ~ 5.5 V 工作溫度:-40°C ~ 125°C 安裝類型:表面貼裝 封裝/外殼:SOT-23-8 供應(yīng)商設(shè)備封裝:SOT-23-8 包裝:Digi-Reel® 其它名稱:296-22675-6
ADT7460ARQ-REEL 功能描述:IC SENSOR TEMP FAN-CTRL 16QSOP RoHS:否 類別:集成電路 (IC) >> PMIC - 熱管理 系列:dBCool® 標準包裝:1 系列:- 功能:溫度監(jiān)控系統(tǒng)（傳感器） 傳感器類型:內(nèi)部和外部 感應(yīng)溫度:-40°C ~ 125°C，外部傳感器 精確度:±2.5°C 本地（最大值），±5°C 遠程（最大值） 拓撲:ADC，比較器，寄存器庫 輸出類型:2 線 SMBus? 輸出警報:無 輸出風扇:無 電源電壓:2.7 V ~ 5.5 V 工作溫度:-40°C ~ 125°C 安裝類型:表面貼裝 封裝/外殼:SOT-23-8 供應(yīng)商設(shè)備封裝:SOT-23-8 包裝:Digi-Reel® 其它名稱:296-22675-6
ADT7460ARQ-REEL7 功能描述:IC SENSOR TEMP FAN-CTRL 16QSOP RoHS:否 類別:集成電路 (IC) >> PMIC - 熱管理 系列:dBCool® 標準包裝:1 系列:- 功能:溫度監(jiān)控系統(tǒng)（傳感器） 傳感器類型:內(nèi)部和外部 感應(yīng)溫度:-40°C ~ 125°C，外部傳感器 精確度:±2.5°C 本地（最大值），±5°C 遠程（最大值） 拓撲:ADC，比較器，寄存器庫 輸出類型:2 線 SMBus? 輸出警報:無 輸出風扇:無 電源電壓:2.7 V ~ 5.5 V 工作溫度:-40°C ~ 125°C 安裝類型:表面貼裝 封裝/外殼:SOT-23-8 供應(yīng)商設(shè)備封裝:SOT-23-8 包裝:Digi-Reel® 其它名稱:296-22675-6
ADT7460ARQZ 功能描述:馬達/運動/點火控制器和驅(qū)動器 THERMAL MGMT CNTRLR IC RoHS:否 制造商:STMicroelectronics 產(chǎn)品:Stepper Motor Controllers / Drivers 類型:2 Phase Stepper Motor Driver 工作電源電壓:8 V to 45 V 電源電流:0.5 mA 工作溫度:- 25 C to + 125 C 安裝風格:SMD/SMT 封裝 / 箱體:HTSSOP-28 封裝:Tube
ADT7460ARQZ-R7 制造商:ON Semiconductor 功能描述:Temp Sensor Digital Serial (3-Wire) 16-Pin QSOP T/R
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