- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄165354 > ADT7462ACPZ-500RL7 (ON SEMICONDUCTOR) DIGITAL TEMP SENSOR-SERIAL, 8BIT(s), 4Cel, SQUARE, SURFACE MOUNT PDF資料下載
參數(shù)資料
| 型號： | ADT7462ACPZ-500RL7 |
| 廠商： | ON SEMICONDUCTOR |
| 元件分類： | 溫度/濕度傳感器 |
| 英文描述： | DIGITAL TEMP SENSOR-SERIAL, 8BIT(s), 4Cel, SQUARE, SURFACE MOUNT |
| 封裝： | 5 X 5 MM, LFCSP-32 |
| 文件頁數(shù)： | 17/88頁 |
| 文件大?。?/td> | 836K |
| 代理商： | ADT7462ACPZ-500RL7 |
第1頁第2頁第3頁第4頁第5頁第6頁第7頁第8頁第9頁第10頁第11頁第12頁第13頁第14頁第15頁第16頁當(dāng)前第17頁第18頁第19頁第20頁第21頁第22頁第23頁第24頁第25頁第26頁第27頁第28頁第29頁第30頁第31頁第32頁第33頁第34頁第35頁第36頁第37頁第38頁第39頁第40頁第41頁第42頁第43頁第44頁第45頁第46頁第47頁第48頁第49頁第50頁第51頁第52頁第53頁第54頁第55頁第56頁第57頁第58頁第59頁第60頁第61頁第62頁第63頁第64頁第65頁第66頁第67頁第68頁第69頁第70頁第71頁第72頁第73頁第74頁第75頁第76頁第77頁第78頁第79頁第80頁第81頁第82頁第83頁第84頁第85頁第86頁第87頁第88頁
ADT7462
Rev. 2 | Page 24 of 88 | www.onsemi.com
Offset Registers
The ADT7462 has temperature offset registers at Register 0x56
to Register 0x59 for the local, Remote 1, Remote 2, and Remote 3
temperature channels. By doing a one-time calibration of the
system, the user can determine the offset caused by system
board noise and cancel it using the offset registers. The offset
registers automatically add a twos complement, 8-bit reading to
every temperature measurement. The LSBs add 0.5°C offset to
the temperature reading so the 8-bit register effectively allows
temperature offsets of 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.
Temperature Offset Registers
Register 0x56 Local Temperature Offset = 0x00 (0°C default)
Register 0x57 Remote 1 Temperature Offset = 0x00 (0°C default)
Register 0x58 Remote 2 Temperature Offset = 0x00 (0°C default)
Register 0x59 Remote 3 Temperature Offset = 0x00 (0°C default)
Layout Considerations
Digital boards can be electrically noisy environments. The
ADT7462 measures very small voltages from the remote sensor,
so care must be taken to minimize noise induced at the sensor
inputs. The following precautions should be taken:
Place the ADT7462 as close as possible to the remote
sensing diode. Provided that the worst noise sources, such
as clock generators, data/address buses, and CRTs, are
avoided, this distance can be 4 inches to 8 inches.
Route the D+ and D tracks close together, in parallel,
with grounded guard tracks on each side. To minimize
inductance and reduce noise pickup, a 5 mil track width
and spacing is recommended. If possible, provide a ground
plane under the tracks.
5MIL
GND
D+
GND
D–
0556
9-
025
Figure 35. Typical Arrangement of Signal Tracks
Minimize the number of copper/solder joints that can
cause thermocouple effects. Where copper/solder joints are
used, make sure that they are in both the D+ and D path
and at the same temperature.
Thermocouple effects should not be a major problem
because 1°C corresponds to about 200 mV, and thermocouple
voltages are about 3 mV/°C of temperature difference.
Unless there are two thermocouples with a large tempera-
ture differential between them, thermocouple voltages
should be much less than 200 mV.
Place a 0.1 μF bypass capacitor close to the VCC pin. In
extremely noisy environments, an input filter capacitor
can be placed across D+ and D close to the ADT7462.
This capacitance can affect the temperature measurement,
so care must be taken to ensure that any capacitance seen
at D+ and D is a maximum of 1000 pF. This maximum
value includes the filter capacitance, plus any cable or stray
capacitance between the pins and the sensor diode.
If the distance to the remote sensor is more than 8 inches,
the use of twisted pair cable is recommended. This works
from about 6 feet up to 12 feet.
For really long distances (up to 100 feet), use shielded
twisted pair, such as Belden No. 8451 microphone cable.
Connect the twisted pair to D+ and D and the shield to
GND close to the ADT7462. Leave the remote end of the
shield unconnected to avoid ground loops.
Because the measurement technique uses switched current
sources, excessive cable or filter capacitance can affect the
measurement. When using long cables, the filter capaci-
tance can be reduced or removed.
Noise Filtering
For temperature sensors operating in noisy environments, the
industry-standard practice is to place a capacitor across the D+
and D pins to help combat the effects of noise. However, large
capacitances affect the accuracy of the temperature measure-
ment, leading to a recommended maximum capacitor value of
1000 pF. While this capacitor does reduce noise, it does not
eliminate it, making it difficult to use the sensor in a very noisy
environment.
The ADT7462 has a major advantage over other devices in
eliminating the effects of noise on the external sensor. The
series resistance cancellation feature allows a filter to be
constructed between the external temperature sensor and the
device. The effect of any filter resistance seen in series with the
remote sensor is automatically canceled from the temperature
result.
The construction of a filter allows the ADT7462 and the remote
temperature sensor to operate in noisy environments. Figure 36
shows a low-pass RCR filter, with the following values:
R = 100 Ω
C = 1 nF
This filtering reduces both common-mode noise and
differential noise.
100
1nF
REMOTE
SENSOR
05
569-
02
6
D+
D–
Figure 36. Filter Between Remote Sensor and the ADT7462
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| ADTSM66SV | KEYPAD SWITCH, SPST, MOMENTARY-TACTILE, 0.05A, 12VDC, 3.92 N, SURFACE MOUNT-STRAIGHT |
| ADTS644N/KV | KEYPAD SWITCH, SPST, MOMENTARY-TACTILE, 0.05A, 12VDC, 1.57 N, THROUGH HOLE-STRAIGHT |
| ADTSM648N/KV | KEYPAD SWITCH, SPST, MOMENTARY-TACTILE, 0.05A, 12VDC, 1.57 N, SURFACE MOUNT-STRAIGHT |
| ADTS62KVB | KEYPAD SWITCH, SPST, MOMENTARY-TACTILE, 0.05A, 12VDC, 1.47 N, THROUGH HOLE-STRAIGHT |
| ADUC7022BCP | 32-BIT, FLASH, 45.5 MHz, RISC MICROCONTROLLER, QCC40 |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| ADT7462ACPZ-5RL7 | 功能描述:監(jiān)控電路 FLX H/WRE MON IC SRV RoHS:否 制造商:STMicroelectronics 監(jiān)測電壓數(shù): 監(jiān)測電壓: 欠電壓閾值: 過電壓閾值: 輸出類型:Active Low, Open Drain 人工復(fù)位:Resettable 監(jiān)視器:No Watchdog 電池備用開關(guān):No Backup 上電復(fù)位延遲（典型值）:10 s 電源電壓-最大:5.5 V 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:UDFN-6 封裝:Reel |
| ADT7462ACPZ-R7 | 功能描述:監(jiān)控電路 FLX H/WRE MON IC SRV RoHS:否 制造商:STMicroelectronics 監(jiān)測電壓數(shù): 監(jiān)測電壓: 欠電壓閾值: 過電壓閾值: 輸出類型:Active Low, Open Drain 人工復(fù)位:Resettable 監(jiān)視器:No Watchdog 電池備用開關(guān):No Backup 上電復(fù)位延遲（典型值）:10 s 電源電壓-最大:5.5 V 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:UDFN-6 封裝:Reel |
| ADT7462ACPZ-REEL | 功能描述:監(jiān)控電路 FLX H/WRE MON IC SRV RoHS:否 制造商:STMicroelectronics 監(jiān)測電壓數(shù): 監(jiān)測電壓: 欠電壓閾值: 過電壓閾值: 輸出類型:Active Low, Open Drain 人工復(fù)位:Resettable 監(jiān)視器:No Watchdog 電池備用開關(guān):No Backup 上電復(fù)位延遲（典型值）:10 s 電源電壓-最大:5.5 V 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:UDFN-6 封裝:Reel |
| ADT7462ACPZ-REEL7 | 功能描述:IC TEMP/VOLT MONITOR 32-LFCSP 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: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 |
| ADT7462EBZEVB | 功能描述:EVALUATION BOARD ADT7462 制造商:on semiconductor 系列:* 零件狀態(tài):在售 標(biāo)準(zhǔn)包裝:1 |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。