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參數(shù)資料
| 型號(hào)： | LM75A |
| 廠商： | NXP Semiconductors N.V. |
| 元件分類： | 溫度/濕度傳感器 |
| 英文描述： | Digital temperature sensor and thermal Watchdog |
| 中文描述： | 數(shù)字溫度傳感器和熱看門狗 |
| 文件頁數(shù)： | 11/18頁 |
| 文件大小： | 126K |
| 代理商： | LM75A |
Philips Semiconductors
Product data sheet
LM75A
Digital temperature sensor and thermal Watchdog
2004 Oct 05
11
OS output and polarity
The OS output is an open-drain output and its state represents
results of the device Watchdog operation as described in the
“General operation” section. In order to observe this output state, an
external pull-up resistor is needed. The resistor should be as large
as possible, up 200 k
, to minimize the temp reading error due to
internal heating by the high OS sinking current.
The OS output active state can be selected as HIGH or LOW by
programming bit B2 of the Configuration register: setting B2 to 1
selects OS active HIGH and setting B2 to 0 sets OS active LOW.
At power-up, this bit is equal to 0 and the OS active state is LOW.
OS comparator and interrupt modes
As described in the “General operation” section, the device OS
output responds to the result of the comparison between the Temp
data and the programmed limits, Tos and Thyst, in different ways
depending on the selected OS mode: OS comparator or OS
interrupt. The OS mode is selected by programming bit B1 of the
configuration register: setting B1 to 1 selects the OS interrupt mode,
and setting B1 to 0 selects the OS comparator mode. At power up,
this bit is equal to 0 and the OS comparator is selected.
The main difference between the two modes is that in OS
comparator mode, the OS output becomes active when the Temp
has exceeded the Tos and reset when the Temp has dropped below
the Thyst, reading a register or putting the device into shut-down
does not change the state of the OS output; while in OS interrupt
mode, once it has been activated either by exceeding the Tos or
dropping below the Thyst, the OS output will remain active
indefinitely until reading a register or putting the device into
shut-down occurs, then the OS output is reset.
The Tos & Thyst limits must be selected so that Tos temp value >
Thyst temp value. Otherwise, the OS output state will be undefined.
OS fault queue
Fault queue is defined as the number of faults that must occur
consecutively to activate the OS output. It is provided to avoid false
tripping due to noise. Because faults are determined at the end of
data conversions, fault queue is also defined as the number of
consecutive conversions returning a temperature trip. The value of
fault queue is selectable by programming the two bits B4 and B3 of
the configuration register. Notice that the programmed data and the
fault queue value are not the same. The Fault queue table (Table 11)
shows the one-to-one relationship between them. At power-up, fault
queue data = 0 and fault queue value = 1.
Table 11. Fault queue table
Fault queue data
Fault queue value
B4
B3
Decimal
0
0
1
0
1
2
1
0
4
1
1
6
Shutdown mode
The device operation mode is selected by programming bit B0 of the
Configuration register: Setting B0 to 1 will put the device into
shut-down mode. Resetting B0 to 0 for the device normal mode.
In shut-down mode, the device draws a small current of about
3.5
μ
A and the power dissipation is minimized; the temperature
conversion stops, but the I
2
C interface remains active and register
write/read operation can be performed. If the OS output is in
comparator mode, then it remains unchanged. Otherwise, the OS
output is reset in interrupt mode.
Power-up default and Power-on Reset
The LM75A always powers-up in its default state with:
– Normal operation mode
– OS comparator mode
– Tos = 80
°
C
– Thyst = 75
°
C
– OS output active state = LOW
– Pointer value = 0.
When the power supply voltage is dropped below the device
power-on reset level of about 1.9 V (POR) and then rises up again,
the device will be reset to its default condition as listed above.
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| LM75AD | 制造商:NXP Semiconductors 功能描述: |
| LM75AD,112 | 功能描述:板上安裝溫度傳感器 I2C LOCAL +/- 2OC TS 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 |
| LM75AD,118 | 功能描述:板上安裝溫度傳感器 I2C LOCAL +/- 2OC TS 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 |
| LM75AD.112 | 制造商:PHILIPS 制造商全稱:NXP Semiconductors 功能描述:Digital temperature sensor and thermal watchdog |
| LM75AD/G-T | 功能描述:IC I2C TEMP SNSR/WATCHDOG 8-SOIC RoHS:是 類別:集成電路 (IC) >> PMIC - 熱管理 系列:- 標(biāo)準(zhǔn)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(yuǎn)程（最大值） 拓?fù)?ADC，比較器，寄存器庫 輸出類型:2 線 SMBus? 輸出警報(bào):無 輸出風(fēng)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 |
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