- 您现在的位置：买卖IC网 > PDF目录22015 > ADT7490ARQZ (ON Semiconductor)IC MON/FAN CTRLR REMOTE 24-QSOP PDF资料下载
参数资料
| 型号： | ADT7490ARQZ |
| 厂商： | ON Semiconductor |
| 文件页数： | 19/75页 |
| 文件大小： | 0K |
| 描述： | IC MON/FAN CTRLR REMOTE 24-QSOP |
| 产品变化通告： | MFG CHG Notification ADI to ON Semi QSOP 24ld Pkg (MSL) Change 17/Jun/2010 Product Discontinuation 30/Sept/2011 |
| 标准包装： | 56 |
| 系列： | dBCool® |
| 功能： | 风扇控制，温度监控器 |
| 传感器类型： | 内部和外部 |
| 感应温度： | -40°C ~ 125°C |
| 精确度： | ±1.5°C（最小值） |
| 拓扑： | ADC，比较器，风扇速度计数器，多路复用器，寄存器库 |
| 输出类型： | SMBus? |
| 输出警报： | 无 |
| 输出风扇： | 是 |
| 电源电压： | 3 V ~ 3.6 V |
| 工作温度： | -40°C ~ 125°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 24-SSOP（0.154"，3.90mm 宽） |
| 供应商设备封装： | 24-QSOP |
| 包装： | 管件 |
第1页第2页第3页第4页第5页第6页第7页第8页第9页第10页第11页第12页第13页第14页第15页第16页第17页第18页当前第19页第20页第21页第22页第23页第24页第25页第26页第27页第28页第29页第30页第31页第32页第33页第34页第35页第36页第37页第38页第39页第40页第41页第42页第43页第44页第45页第46页第47页第48页第49页第50页第51页第52页第53页第54页第55页第56页第57页第58页第59页第60页第61页第62页第63页第64页第65页第66页第67页第68页第69页第70页第71页第72页第73页第74页第75页
ADT7490
Table 17. TWOS COMPLEMENT TEMPERATURE DATA
FORMAT
Temperature Digital Output (10-bit) (Note 1)
–128 ? C 1000 0000 00 (Diode Fault)
it could equally be a discrete transistor, such as a
2N3904/2N3906.
If a discrete transistor is used, the collector is not grounded
and should be linked to the base. If a PNP transistor is used,
the base is connected to the D– input and the emitter to the
D+
–63 ? C
–50 ? C
–25 ? C
–10 ? C
0 ? C
10.25 ? C
25.5 ? C
50.75 ? C
75 ? C
100 ? C
1100 0001 00
1100 1110 00
1110 0111 00
1111 0110 00
0000 0000 00
0000 1010 01
0001 1001 10
0011 0010 11
0100 1011 00
0110 0100 00
D+ input. If an NPN transistor is used, the emitter is
connected to the D– input and the base to the D+ input.
Figure 25 and Figure 26 show how to connect the ADT7490
to an NPN or PNP transistor for temperature measurement.
ADT7490
2N3904
NPN
D ?
Figure 25. Measuring Temperature by Using
an NPN Transistor
125 ? C 0111 1101 00
127 ? C 0111 1111 00
1. Bold numbers denote 2 LSBs of measurement in the Extended
Resolution 2 register (Register 0x77) with 0.25 ? C resolution.
2N3906
PNP
ADT7490
D+
D ?
Table 18. OFFSET 6 4 DATA FORMAT
Figure 26. Measuring Temperature by Using
Temperature
–64 ? C
–63 ? C
–1 ? C
0 ? C
1 ? C
10 ? C
25 ? C
50 ? C
75 ? C
100 ? C
125 ? C
Digital Output (10-bit) (Note 1)
0000 0000 00 (Diode Fault)
0000 0001 00
0011 1111 00
0100 0000 00
0100 0001 00
0100 1010 00
0101 1001 00
0111 0010 00
1000 1001 00
1010 0100 00
1011 1101 00
a PNP Transistor
To prevent ground noise from interfering with the
measurement, the more negative terminal of the sensor is not
referenced to ground, but is biased above ground by an
internal diode at the D ? input. C1 can optionally be added as
a noise filter (recommended maximum value of 1,000 pF).
However, a better option in noisy environments is to add a
filter, as described in the section.
Remote Temperature Measurement
The ADT7490 can measure the temperature of two remote
diode sensors or diode-connected transistors connected to
Pin 10 and Pin 11, or Pin 12 and Pin 13.
The forward voltage of a diode or diode-connected
191 ? C 1111 1111 00
1. Bold numbers denote 2 LSBs of measurement in the Extended
Resolution 2 register (Register 0x77) with 0.25 ? C resolution.
Thermal Diode Temperature Measurement Method
A simple method of measuring temperature is to exploit
the negative temperature coefficient of a diode, measuring
the base-emitter voltage (V BE ) of a transistor operated at
constant current. Unfortunately, this technique requires
calibration to null out the effect of the absolute value of V BE ,
which varies from device to device.
The technique used in the ADT7490 is to measure the
change in V BE when the device is operated at three different
currents. Previous devices have used only two operating
currents, but the use of a third current allows automatic
cancellation of resistances in series with the external
temperature sensor.
Figure 28 shows the input signal conditioning used to
measure the output of an external temperature sensor. This
figure shows the external sensor as a substrate transistor, but
transistor operated at a constant current exhibits a negative
temperature coefficient of about ? 2 mV/ ? C. Unfortunately,
the absolute value of V BE varies from device to device, and
individual calibration is required to null this out. Therefore,
the technique is unsuitable for mass production. The
technique used in the ADT7490 is to measure the change in
V BE when the device is operated at three different currents.
This is given by:
q
D V BE + kT In(N) (eq. 2)
where:
k is the Boltzmann constant.
q is the charge on the carrier.
T is the absolute temperature in Kelvin.
N is the ratio of the two currents.
To measure D V BE , the operating current through the
sensor is switched among three related currents. N1 ? I and
N2 ? I are different multiples of the current I, as shown in
Figure 27. The currents through the temperature diode are
http://onsemi.com
19
相关PDF资料 |
PDF描述 |
|---|---|
| AMC25DREN-S13 | CONN EDGECARD 50POS .100 EXTEND |
| GCC05DRES | CONN EDGECARD 10POS .100 EYELET |
| A101K15C0GK5TAA | CAP CER 100PF 200V 10% NP0 AXIAL |
| ECM18DCBH | CONN EDGECARD 36POS R/A .156 SLD |
| AMC25DREH-S13 | CONN EDGECARD 50POS .100 EXTEND |
相关代理商/技术参数 |
参数描述 |
|---|---|
| ADT7490ARQZ-R7 | 功能描述:马达/运动/点火控制器和驱动器 FAN CNTRL W/PECI INT RoHS:否 制造商:STMicroelectronics 产品:Stepper Motor Controllers / Drivers 类型:2 Phase Stepper Motor Driver 工作电源电压:8 V to 45 V 电源电流:0.5 mA 工作温度:- 25 C to + 125 C 安装风格:SMD/SMT 封装 / 箱体:HTSSOP-28 封装:Tube |
| ADT7490ARQZ-REEL | 功能描述:马达/运动/点火控制器和驱动器 FAN CNTRL W/PECI INT RoHS:否 制造商:STMicroelectronics 产品:Stepper Motor Controllers / Drivers 类型:2 Phase Stepper Motor Driver 工作电源电压:8 V to 45 V 电源电流:0.5 mA 工作温度:- 25 C to + 125 C 安装风格:SMD/SMT 封装 / 箱体:HTSSOP-28 封装:Tube |
| ADT7490ARQZ-REEL7 | 功能描述:IC THERM MON FAN CTRLR 24-QSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 热管理 系列:dBCool® 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 |
| ADT7490ZEVB | 功能描述:BOARD EVALUATION FOR ADT7490 RoHS:是 类别:编程器，开发系统 >> 过时/停产零件编号 系列:dBCool® 标准包装:1 系列:- 传感器类型:CMOS 成像，彩色（RGB） 传感范围:WVGA 接口:I²C 灵敏度:60 fps 电源电压:5.7 V ~ 6.3 V 嵌入式:否 已供物品:成像器板 已用 IC / 零件:KAC-00401 相关产品:4H2099-ND - SENSOR IMAGE WVGA COLOR 48-PQFP4H2094-ND - SENSOR IMAGE WVGA MONO 48-PQFP |
| ADT75 | 制造商:AD 制造商全称:Analog Devices 功能描述:+-1∑C Accurate, 12-Bit Digital Temperature Sensor |
发布紧急采购，3分钟左右您将得到回复。