LM75A_4
?NXP B.V. 2007. All rights reserved.
Product data sheet
Rev. 04 10 July 2007
4 of 24
NXP Semiconductors
LM75A
Digital temperature sensor and thermal watchdog
7. Functional description
7.1 General operation
The LM75A uses the on-chip band gap sensor to measure the device temperature with
the resolution of 0.125 癈 and stores the 11-bit 2's complement digital data, resulted from
11-bit A-to-D conversion, into the device Temp register. This Temp register can be read at
any time by a controller on the I
2
C-bus. Reading temperature data does not affect the
conversion in progress during the read operation.
The device can be set to operate in either mode: normal or shutdown. In normal operation
mode, the temp-to-digital conversion is executed every 100 ms and the Temp register is
updated at the end of each conversion. In shutdown mode, the device becomes idle, data
conversion is disabled and the Temp register holds the latest result; however, the device
I
2
C-bus interface is still active and register write/read operation can be performed. The
device operation mode is controllable by programming bit B0 of the conguration register.
The temperature conversion is initiated when the device is powered-up or put back into
normal mode from shutdown.
In addition, at the end of each conversion in normal mode, the temperature data (or Temp)
in the Temp register is automatically compared with the overtemperature shutdown
threshold data (or Tos) stored in the Tos register, and the hysteresis data (or Thyst) stored
in the Thyst register, in order to set the state of the device OS output accordingly. The
device Tos and Thyst registers are write/read capable, and both operate with 9-bit
2's complement digital data. To match with this 9-bit operation, the Temp register uses
only the 9 MSB bits of its 11-bit data for the comparison.
The way that the OS output responds to the comparison operation depends upon the OS
operation mode selected by conguration bit B1, and the user-dened fault queue dened
by conguration bits B3 and B4.
In OS comparator mode, the OS output behaves like a thermostat. It becomes active
when the Temp exceeds the T
os
, and is reset when the Temp drops below the T
hyst
.
Reading the device registers or putting the device into shutdown does not change the
state of the OS output. The OS output in this case can be used to control cooling fans or
thermal switches.
In OS interrupt mode, the OS output is used for thermal interruption. When the device is
powered-up, the OS output is rst activated only when the Temp exceeds the T
os
; then it
remains active indenitely until being reset by a read of any register. Once the OS output
has been activated by crossing T
os
and then reset, it can be activated again only when the
Temp drops below the T
hyst
; then again, it remains active indenitely until being reset by a
read of any register. The OS interrupt operation would be continued in this sequence:
T
os
trip, Reset, T
hyst
trip, Reset, T
os
trip, Reset, T
hyst
trip, Reset, etc.
A1
6
Digital input. User-dened address bit 1.
A0
7
Digital input. User-dened address bit 0.
V
CC
8
Power supply.
Table 3.
Pin description &continued
Symbol
Pin
Description
发布紧急采购，3分钟左右您将得到回复。
相关PDF资料
LM75BD,112
IC TEMP SENSOR DIGITAL 8-SOIC
LM75BIMX-5+
IC TEMP SENSOR WATCHDOG 8SOIC
LM92CIMX/NOPB
IC SENSOR TEMP/THERM COMP 8-SOIC
LT1123CST#TRPBF
IC REG CTRLR SGL 5V SOT223
LT1248IS#PBF
IC PFC CTRLR AVERAGE CURR 16SOIC
LT1249IS8#PBF
IC PFC CTRLR AVERAGE CURR 8SOIC
LT1577CS-3.3/2.8#TRPBF
IC REG CTRLR DUAL OUT 16SOIC
LT1640HIN8#PBF
IC CONTRLR HOTSWAP NEGVOLT 8-DIP
相关代理商/技术参数
LM75AD,118
功能描述:板上安装温度传感器 I2C LOCAL +/- 2OC TS RoHS:否 制造商:Omron Electronics 输出类型:Digital 配置: 准确性:+/- 1.5 C, +/- 3 C 温度阈值: 数字输出 - 总线接口:2-Wire, I2C, SMBus 电源电压-最大:5.5 V 电源电压-最小:4.5 V 最大工作温度:+ 50 C 最小工作温度:0 C 关闭: 安装风格: 封装 / 箱体: 设备功能:Temperature and Humidity Sensor
LM75AD.112
制造商:PHILIPS 制造商全称: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 类别:集成电路 (IC) >> PMIC - 热管理 系列:- 标准包装:1 系列:- 功能:温度监控系统（传感器） 传感器类型:内部和外部 感应温度:-40°C ~ 125°C，外部传感器 精确度:±2.5°C 本地（最大值），±5°C 远程（最大值） 拓扑:ADC，比较器，寄存器库 输出类型:2 线 SMBus? 输出警报:无 输出风扇:无 电源电压:2.7 V ~ 5.5 V 工作温度:-40°C ~ 125°C 安装类型:表面贴装 封装/外壳:SOT-23-8 供应商设备封装:SOT-23-8 包装:Digi-Reel® 其它名称:296-22675-6
LM75AD112
制造商:Rochester Electronics LLC 功能描述: 制造商:NXP 功能描述: 制造商:NXP Semiconductors 功能描述:
LM75ADP
制造商:NXP Semiconductors 功能描述:Digital Temp Sensor 2-Wire,LM75ADP
LM75ADP,118
功能描述:板上安装温度传感器 TEMP SENSOR DIGITAL RoHS:否 制造商:Omron Electronics 输出类型:Digital 配置: 准确性:+/- 1.5 C, +/- 3 C 温度阈值: 数字输出 - 总线接口:2-Wire, I2C, SMBus 电源电压-最大:5.5 V 电源电压-最小:4.5 V 最大工作温度:+ 50 C 最小工作温度:0 C 关闭: 安装风格: 封装 / 箱体: 设备功能:Temperature and Humidity Sensor
LM75ADP,118
制造商:NXP Semiconductors 功能描述:IC, TEMP SENSOR, 0.125C, 3C, TSSOP-8
LM75ADP,118-CUT TAPE
制造商:NXP 功能描述:LM75A Series SMD 5.5 mA Digital Temperature Sensor w/ Thermal Watchdog TSSOP-8