收藏本站
ADT7468
?
?
Base-emitter voltage greater than 0.25 V at 6 μA, with the
highest operating temperature.
Base-emitter voltage less than 0.95 V at 100 μA, with the
ADT7468
D+
?
lowest operating temperature.
Base resistance less than 100 ?.
2N3906
PNP
D–
?
Small variation in h FE (from 50 to 150), which indicates
Figure 26. Measuring Temperature Using a PNP Transistor
tight control of V BE characteristics.
Transistors, such as 2N3904, 2N3906, or equivalents in SOT-23
packages, are suitable devices to use.
Table 7. Temperature Data Format
Nulling Temperature Errors
As CPUs are developed that run faster, it is getting more
difficult to avoid high frequency clocks when routing the
D+/D– traces around a system board. Even when
Temperature
–128°C
–125°C
–100°C
–75°C
–50°C
–25°C
–10°C
0°C
10.25°C
25.5°C
50.75°C
75°C
100°C
125°C
127°C
Digital Output (10-Bit) 1
1000 0000 00
1000 0011 00
1001 1100 00
1011 0101 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
0111 1101 00
0111 1111 00
recommended layout guidelines are followed, some temperature
errors may still be attributed to noise coupled onto the D+/D–
lines. Constant high frequency noise usually attenuates or
increases temperature measurements by a linear, constant value.
The ADT7468 has temperature offset registers at Addresses 0x70
and 0x72 for the Remote 1 and Remote 2 temperature channels.
By doing a one-time calibration of the system, the user can
determine the offset caused by system board noise and null it
using the offset registers. The offset registers automatically add
an Offset 64/twos complement 8-bit reading to every
temperature measurement. The LSBs add 0.5°C offset to the
temperature reading; therefore, the 8-bit register effectively
allows temperature offsets up to ±64°C with a resolution of
0.5°C. This ensures that the readings in the temperature
measurement registers are as accurate as possible.
1
Bold numbers denote 2 LSB of measurement in Extended Resolution
Register 2 (Reg. 0x77) with 0.25°C resolution.
Temperature Offset Registers
Reg. 0x70, Remote 1 temperature offset = 0x00 (0°C default)
Table 8. Extended Range, Temperature Data Format
Reg. 0x71, Local temperature offset = 0x00 (0°C default)
Temperature
–64°C
–1°C
0°C
1°C
10°C
25°C
50°C
75°C
100°C
125°C
191°C
Digital Output (10-Bit) 1
0000 0000 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
1111 1111 00
Reg. 0x72, Remote 2 temperature offset = 0x00 (0°C default)
ADT7463/ADT7468 Backwards Compatible Mode
By setting Bit 1 of Configuration Register 5 (0x7C), all
temperature measurements are stored in the zone temperature
value registers (0x25, 0x26, and 0x27) in twos complement in the
range of ?64°C to +127°C (the ADT7468 makes calculations based
on the Offset 64 extended range and clamps the results, if
necessary.) The temperature limits must be reprogrammed in twos
complement. If a twos complement temperature below ?63°C is
entered, the temperature is clamped to ?63°C. In this mode, the
diode fault condition remains at ?128°C = 1000 0000, while in the
extended temperature range (?64°C to +191°C) the fault condition
1
Bold numbers denote 2 LSB of measurement in Extended Resolution
Register 2 (Reg. 0x77) with 0.25°C resolution.
ADT7468
is represented by ?64°C = 0000 0000.
Temperature Measurement Registers
Reg. 0x25, Remote 1 temperature
Reg. 0x26, Local temperature
2N3904
NPN
D+
D–
Reg. 0x27, Remote 2 temperature
Reg. 0x77, Extended Resolution 2 = 0x00 default
<7:6> TDM2, Remote 2 temperature LSBs
Figure 25. Measuring Temperature Using an NPN Transistor
<5:4> LTMP, local temperature LSBs
<3:2> TDM1, Remote 1 temperature LSBs
Rev. 3 | Page 20 of 81 | www.onsemi.com
发布紧急采购，3分钟左右您将得到回复。

采购需求

(若只采购一条型号，填写一行即可)

发布成功！您可以继续发布采购。也可以进入我的后台，查看报价

发布成功！您可以继续发布采购。也可以进入我的后台，查看报价

*型号 *数量 厂商 批号 封装
添加更多采购

我的联系方式

*
*
*
相关PDF资料
ADT7473ZEVB BOARD EVALUATION FOR ADT7473
ADT7475EBZEVB BOARD EVALUATION FOR ADT7475
ADT7476EBZEVB BOARD EVALUATION FOR ADT7476
ADT7490ZEVB BOARD EVALUATION FOR ADT7490
ADZS-21262-1-EZEXT BOARD DAUGHTER FOR ADSP-21262
ADZS-BF-EZEXT-1 BOARD DAUGHTER ADSP-BF533/561KIT
ADZS-BFAV-EZEXT BOARD DAUGHT ADSP-BF533,37,61KIT
ADZS-BFSHUSB-EZEXT BOARD DAUGHTER EZ EXTENDER
相关代理商/技术参数
ADT7470 制造商:AD 制造商全称:Analog Devices 功能描述:Temperature Sensor Hub and Fan Controller
ADT7470_13 制造商:AD 制造商全称:Analog Devices 功能描述:Temperature Sensor Hub and Fan Controller
ADT7470ARQ 制造商:Analog Devices 功能描述:Temp Sensor Digital Serial (I2C) 16-Pin QSOP
ADT7470ARQ-REEL 制造商:Rochester Electronics LLC 功能描述: 制造商:Analog Devices 功能描述:
ADT7470ARQ-REEL7 制造商:Analog Devices 功能描述:Temp Sensor Digital Serial (I2C) 16-Pin QSOP T/R
ADT7470ARQZ 功能描述:IC SENSOR TEMP FAN CTRLR 16QSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 热管理 系列:- 标准包装:3,000 系列:- 功能:温度开关 传感器类型:内部 感应温度:85°C 分界点 精确度:±6°C（最小值） 拓扑:ADC（三角积分型），比较器，寄存器库 输出类型:开路漏极 输出警报:是 输出风扇:是 电源电压:2.7 V ~ 5.5 V 工作温度:-55°C ~ 125°C 安装类型:表面贴装 封装/外壳:SC-74A，SOT-753 供应商设备封装:SOT-23-5 包装:带卷 (TR) 其它名称:ADT6501SRJZP085RL7-ND
ADT7470ARQZ-REEL 功能描述:IC SENSOR TEMP FAN CTRLR 16QSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 热管理 系列:- 标准包装:2,500 系列:SilentSense™ 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:-55°C ~ 125°C，外部传感器 精确度:±2°C 本地（最大），±3°C 远程（最大） 拓扑:ADC（三角积分型），比较器，寄存器库 输出类型:I²C?/SMBus? 输出警报:是 输出风扇:是 电源电压:2.7 V ~ 5.5 V 工作温度:-55°C ~ 125°C 安装类型:表面贴装 封装/外壳:8-TSSOP，8-MSOP（0.118"，3.00mm 宽） 供应商设备封装:8-MSOP 包装:带卷 (TR) 其它名称:MIC284-2BMMTRMIC284-2BMMTR-ND
ADT7470ARQZ-REEL7 功能描述:IC SENSOR TEMP FAN CTRLR 16QSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 热管理 系列:- 标准包装:2,500 系列:SilentSense™ 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:-55°C ~ 125°C，外部传感器 精确度:±2°C 本地（最大），±3°C 远程（最大） 拓扑:ADC（三角积分型），比较器，寄存器库 输出类型:I²C?/SMBus? 输出警报:是 输出风扇:是 电源电压:2.7 V ~ 5.5 V 工作温度:-55°C ~ 125°C 安装类型:表面贴装 封装/外壳:8-TSSOP，8-MSOP（0.118"，3.00mm 宽） 供应商设备封装:8-MSOP 包装:带卷 (TR) 其它名称:MIC284-2BMMTRMIC284-2BMMTR-ND