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參數(shù)資料
| 型號： | MAX6641AUB90+T |
| 廠商： | MAXIM INTEGRATED PRODUCTS INC |
| 元件分類： | 溫度/濕度傳感器 |
| 英文描述： | SMBus-Compatible Temperature Monitor with Automatic PWM Fan-Speed Controller |
| 中文描述： | DIGITAL TEMP SENSOR-SERIAL, 8BIT(s), 1Cel, SQUARE, SURFACE MOUNT |
| 封裝： | 3 X 3 MM,LEAD FREE, MO-187C-BA, USOP-10 |
| 文件頁數(shù)： | 4/19頁 |
| 文件大?。?/td> | 538K |
| 代理商： | MAX6641AUB90+T |
frequency setting is used for controlling fans that have
logic-level PWM input pins for speed control. Duty-
cycle resolution is decreased from 2/240 to 4/240 at the
35kHz frequency setting.
PWM Output
The PWMOUT signal is normally used in one of three
ways to control the fan’s speed:
1)
PWMOUT drives the gate of a MOSFET or the base
of a bipolar transistor in series with the fan’s power
supply. The Typical Application Circuit shows the
PWMOUT pin driving an n-channel MOSFET. In this
case, the PWM invert bit (D4 in register 02h) is set to
1. Figure 5 shows PWMOUT driving a p-channel
MOSFET and the PWM invert bit must be set to zero.
2)
PWMOUT is converted (using an external circuit)
into a DC voltage that is proportional to duty cycle.
This duty-cycle-controlled voltage becomes the
power supply for the fan. This approach is less effi-
cient than 1), but can result in quieter fan operation.
Figure 6 shows an example of a circuit that con-
verts the PWM signal to a DC voltage. Because this
circuit produces a full-scale output voltage when
PWMOUT = 0V, bit D4 in register 02h should be set
to zero.
3)
PWMOUT directly drives the logic-level PWM
speed-control input on a fan that has this type of
input. This approach requires fewer external com-
ponents and combines the efficiency of 1) with the
low noise of 2). An example of PWMOUT driving a
fan with a speed-control input is shown in Figure 7.
Bit D4 in register 02h should be set to 1 when this
configuration is used.
Whenever the fan has to start turning from a motionless
state, PWMOUT is forced high for 2s. After this spin-up
period, the PWMOUT duty cycle settles to the predeter-
mined value. If spin-up is disabled (bit 2 in the configu-
ration byte = 1), the duty cycle changes immediately
from zero to the nominal value, ignoring the duty-cycle
rate-of-change setting.
MAX6641
SMBus-Compatible Temperature Monitor with
Automatic PWM Fan-Speed Controller
12
______________________________________________________________________________________
PWM
FREQUENCY
(Hz)
SELECT A
SELECT B
SELECT C
20
00
0
33
01
0
50
10
0
100
11
0
35k
XX
1
Table 5. PWM Frequency Select (10h)
VCC
PWMOUT
10k
5V
P
Figure 5. Driving a P-Channel MOSFET for Top-Side PWM
Fan Drive
+3.3V
PWMOUT
18k
27k
10k
120k
P
+3.3V
+12V
500k
VOUT
TO FAN
1
F
1
F
0.01
F
Figure 6. Driving a Fan with a PWM-to-DC Circuit
VCC
PWMOUT
4.7k
5V
Figure 7. Controlling a PWM Input Fan with the MAX6641’s
PWM Output (Typically, the 35kHz PWM Frequency is Used)
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相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| MAX6641AUB92 | 功能描述:板上安裝溫度傳感器 RoHS:否 制造商:Omron Electronics 輸出類型:Digital 配置: 準(zhǔn)確性:+/- 1.5 C, +/- 3 C 溫度閾值: 數(shù)字輸出 - 總線接口:2-Wire, I2C, SMBus 電源電壓-最大:5.5 V 電源電壓-最小:4.5 V 最大工作溫度:+ 50 C 最小工作溫度:0 C 關(guān)閉: 安裝風(fēng)格: 封裝 / 箱體: 設(shè)備功能:Temperature and Humidity Sensor |
| MAX6641AUB92+ | 功能描述:板上安裝溫度傳感器 SMBus-Compatible Temperature Monitor RoHS:否 制造商:Omron Electronics 輸出類型:Digital 配置: 準(zhǔn)確性:+/- 1.5 C, +/- 3 C 溫度閾值: 數(shù)字輸出 - 總線接口:2-Wire, I2C, SMBus 電源電壓-最大:5.5 V 電源電壓-最小:4.5 V 最大工作溫度:+ 50 C 最小工作溫度:0 C 關(guān)閉: 安裝風(fēng)格: 封裝 / 箱體: 設(shè)備功能:Temperature and Humidity Sensor |
| MAX6641AUB92+T | 功能描述:板上安裝溫度傳感器 SMBus-Compatible Temperature Monitor RoHS:否 制造商:Omron Electronics 輸出類型:Digital 配置: 準(zhǔn)確性:+/- 1.5 C, +/- 3 C 溫度閾值: 數(shù)字輸出 - 總線接口:2-Wire, I2C, SMBus 電源電壓-最大:5.5 V 電源電壓-最小:4.5 V 最大工作溫度:+ 50 C 最小工作溫度:0 C 關(guān)閉: 安裝風(fēng)格: 封裝 / 箱體: 設(shè)備功能:Temperature and Humidity Sensor |
| MAX6641AUB92-T | 功能描述:板上安裝溫度傳感器 RoHS:否 制造商:Omron Electronics 輸出類型:Digital 配置: 準(zhǔn)確性:+/- 1.5 C, +/- 3 C 溫度閾值: 數(shù)字輸出 - 總線接口:2-Wire, I2C, SMBus 電源電壓-最大:5.5 V 電源電壓-最小:4.5 V 最大工作溫度:+ 50 C 最小工作溫度:0 C 關(guān)閉: 安裝風(fēng)格: 封裝 / 箱體: 設(shè)備功能:Temperature and Humidity Sensor |
| MAX6641AUB94 | 功能描述:板上安裝溫度傳感器 RoHS:否 制造商:Omron Electronics 輸出類型:Digital 配置: 準(zhǔn)確性:+/- 1.5 C, +/- 3 C 溫度閾值: 數(shù)字輸出 - 總線接口:2-Wire, I2C, SMBus 電源電壓-最大:5.5 V 電源電壓-最小:4.5 V 最大工作溫度:+ 50 C 最小工作溫度:0 C 關(guān)閉: 安裝風(fēng)格: 封裝 / 箱體: 設(shè)備功能:Temperature and Humidity Sensor |
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