參數(shù)資料
型號(hào): MAX6640YAEE+
廠商: MAXIM INTEGRATED PRODUCTS INC
元件分類: 模擬信號(hào)調(diào)理
英文描述: 2-Channel Temperature Monitor with Dual Automatic PWM Fan-Speed Controller
中文描述: SPECIALTY ANALOG CIRCUIT, PDSO16
封裝: 0.150 INCH, 0.025 INCH PITCH, ROHS COMPLIANT, MO-137AB, QSOP-16
文件頁數(shù): 23/24頁
文件大?。?/td> 428K
代理商: MAX6640YAEE+
MAX6640
perature register read before the scheduled update.
This allows enough time to read the main register
before it is updated, thereby preventing reading the
temperature register data from one conversion and the
extended temperature register data from a different
conversion.
The MAX6640 measures the temperature at a fixed rate
of 4Hz immediately after it is powered on. Setting bit 7
of the configuration register (04h) shuts down the tem-
perature measurement cycle.
OT Output
When a measured temperature exceeds the corre-
sponding OT temperature threshold and OT is not
masked, the associated OT status register bit sets and
the OT output asserts. If OT for the respective channel
is masked, the OT status register sets, but the OT out-
put does not assert. To deassert the OT output and the
associated status register bit, either the measured tem-
perature must fall at least 5°C below the trip threshold
or the trip threshold must be increased to at least 5°C
above the current measured temperature.
THERM
When a measured temperature exceeds the corre-
sponding THERM temperature threshold and THERM is
not masked, the associated THERM status register bit
is set and the THERM output asserts. If THERM for the
respective channel is masked, the THERM status regis-
ter is set, but the THERM output does not assert. To
deassert the THERM output and the associated status
register bit, either the measured temperature must fall
at least 5°C below the trip threshold or the trip thresh-
old must be increased to at least 5°C above the current
measured temperature. Asserting THERM internally or
externally forces both PWM outputs to 100% duty cycle
when bit 6 in address 13h (fan 1) or bit 6 in address
17h (fan 2) is set.
ALERT
The ALERT output asserts to indicate that a measured
temperature exceeds the ALERT trip threshold for that
temperature channel. The status bit and the ALERT out-
put clear by reading the ALERT status register. If the
ALERT status bit is cleared, but the temperature still
exceeds the ALERT temperature threshold, ALERT
reasserts on the next conversion, and the status bit sets
again. A successful alert response protocol clears
ALERT, but does not affect the ALERT status bit.
TACH1 and TACH2 Inputs
To measure the fan speed, the MAX6640 has two
tachometers. Each tachometer has an accurate internal
clock to count the time elapsed in one revolution.
Therefore, it is counting the time between two tachome-
ter pulses for a fan with four poles. When the PWM sig-
nal is used to directly modulate the fan’s power supply,
the PWM frequency is normally in the 20Hz to 100Hz
range. In this case, the time required for one revolution
may be longer than the PWM on-time. For this reason,
the PWM pulses are periodically stretched to allow
tachometer measurement over a full revolution. Turn off
pulse stretching by setting bit 5 of register 13h or regis-
ter 17h when using a 4-wire fan.
The tachometer count is inversely proportional to the
fan’s RPM. The tachometer count data is stored in regis-
ter 20h (for TACH1) and register 21h (for TACH2).
Reading a value of 255 from the TACH count register
means the fan’s RPM is zero or too slow for the range.
Reading a value of zero in the TACH count register
means the fan’s RPM is higher than the range selected.
Table 2 shows the fan’s available RPM ranges. Use reg-
isters 10h or 14h to select the appropriate RPM range for
the fan being used.
FANFAIL
The FANFAIL output asserts to indicate that one of the
fans has failed or is spinning slower than the required
speed. The MAX6640 detects fan fault depending on
the fan control mode. In PWM mode, the MAX6640 pro-
duces a square wave with a duty cycle set by the value
written to the duty-cycle registers (26h and 27h). In this
mode, the MAX6640 signals a fan fault when the
tachometer count is greater than the maximum
tachometer count value stored in the appropriate regis-
ter (22h and 23h). After the MAX6640 asserts FAN
2-Channel Temperature Monitor with Dual
Automatic PWM Fan-Speed Controller
8
_______________________________________________________________________________________
TEMP (
°C)
TEMP (
°C)
DIGITAL OUTPUT
241
+241
1111 0001
240
+240
1111 0000
126
+126
0111 1110
25
+25
0001 1001
1.50
1
0000 0001
0.00
0
0000 0000
Table 1. Temperature Data Byte Format
FAN RPM
RANGE
INTERNAL CLOCK
FREQUENCY (kHz)
2000
1
4000
2
8000
4
16,000
8
Table 2. Tachometer Setting
相關(guān)PDF資料
PDF描述
MAX6640YAEE+T 2-Channel Temperature Monitor with Dual Automatic PWM Fan-Speed Controller
MAX6640AEE+ 2-Channel Temperature Monitor with Dual Automatic PWM Fan-Speed Controller
MAX6641AUB90+ SMBus-Compatible Temperature Monitor with Automatic PWM Fan-Speed Controller
MAX6641AUB90+T SMBus-Compatible Temperature Monitor with Automatic PWM Fan-Speed Controller
MAX6641AUB92+ SMBus-Compatible Temperature Monitor with Automatic PWM Fan-Speed Controller
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
MAX6640YAEE+ 功能描述:板上安裝溫度傳感器 Sensors, Transducers 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
MAX6640YAEE+T 功能描述:板上安裝溫度傳感器 Sensors, Transducers 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
MAX6641AUB90 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
MAX6641AUB90+ 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
MAX6641AUB90+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