參數(shù)資料
型號: AD7416-7418
廠商: Analog Devices, Inc.
元件分類: 溫度/濕度傳感器
英文描述: 10-Bit Digital Temperature Sensor (AD7416) and Single/Four-Channel ADC (AD7417/AD7418)
中文描述: 10位數(shù)字溫度傳感器(I2C接口芯片AD7416)和單/四通道ADC(AD7417/AD7418)
文件頁數(shù): 9/20頁
文件大?。?/td> 325K
代理商: AD7416-7418
REV. G
AD7416/AD7417/AD7418
–9–
TYPICAL CONNECTION DIAGRAM
Figure 2 shows a typical connection diagram for the AD7417.
Using the A0, A1, and A2 pins allows the user to select from up
to eight AD7417s on the same serial bus, if desired. An external
2.5 V reference can be connected at the REF
IN
pin. If an exter-
nal reference is used, a 10
μ
F capacitor should be connected
between REF
IN
and GND. SDA and SCL form the 2-wire I
2
C
compatible interface. For applications where power consump-
tion is of concern, the automatic power-down at the end of a
conversion should be used to improve power performance. See
Operating Modes section of this data sheet.
V
DD
A
IN1
A
IN2
A
IN3
A
IN4
GND
REF
IN
SUPPLY
2.7V TO
5.5V
0.1 F
10 F
10 F FOR
EXTERNAL
REFERENCE
OPTIONAL
EXTERNAL
REFERENCE
AD780/
REF-192
0V TO 2.5V
INPUT
CONVST
SDA
OTI
SCL
2-WIRE
SERIAL
INTERFACE
AD7417
A0
A1
A2
C/ P
Figure 2. Typical Connection Diagram
ANALOG INPUTS
Figure 3 shows an equivalent circuit of the analog input struc-
ture of the AD7417 and AD7418. The two diodes, D1 and D2,
provide ESD protection for the analog inputs. Care must be
taken to ensure that the analog input signal never exceeds the
supply rails by more than 200 mV. This will cause these diodes
to become forward-biased and start conducting current into the
substrate. The maximum current these diodes can conduct
without causing irreversible damage to the part is 20 mA. The
capacitor C2 in Figure 3 is typically about 4 pF and can prima-
rily be attributed to pin capacitance. The resistor R1 is a lumped
component made up of the on resistance of a multiplexer and a
switch. This resistor is typically about 1 k
. The capacitor C1 is
the ADC sampling capacitor and has a capacitance of 3 pF.
A
IN
D1
C1
3pF
V
DD
D2
C2
4pF
V
BALANCE
CONVERT PHASE – SWITCH OPEN
TRACK PHASE – SWITCH CLOSED
R1
1k
Figure 3. Equivalent Analog Input Circuit
ON-CHIP REFERENCE
The AD7416/AD7417/AD7418 has an on-chip 1.2 V band gap
reference that is gained up by a switched capacitor amplifier to
give an output of 2.5 V. The amplifier is only powered up at the
start of the conversion phase and is powered down at the end of
the conversion. The on-chip reference is selected by connecting
the REF
IN
pin to analog ground. This causes SW1 (see Figure 4)
to open and the reference amplifier to power up during a conver-
sion. Therefore, the on-chip reference is not available externally.
An external 2.5 V reference can be connected to the REF
IN
pin.
This has the effect of shutting down the on-chip reference circuitry.
1.2V
REF
IN
SW1
2.5V
EXTERNAL
REFERENCE
DETECT
BUFFER
1.2V
26k
24k
+
+
Figure 4. On-Chip Reference
TEMPERATURE MEASUREMENT
A common method of measuring temperature is to exploit the
negative temperature coefficient of a diode, or the base-emitter
voltage of a transistor, operated at a constant current. Unfortu-
nately, 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 AD7416/AD7417/AD7418 is to
measure the current change in
V
BE
when the device is operated
at two different currents.
This is given by
V
where:
K
is Boltzmann
s constant.
q
is the charge on the electron (1.6
×
10
-19
Coulombs).
T
is the absolute temperature in Kelvins.
N
is the ratio of the two currents.
KT q
n N
1
BE
=
×
/
I
N I
V
DD
SENSING
TRANSISTOR
SENSING
TRANSISTOR
V
OUT
TO ADC
V
OUT
Figure 5. Temperature Measurement Technique
相關(guān)PDF資料
PDF描述
AD7416ACHIPS ECONOLINE: REC2.2-S_DRW(Z)/H* - 2.2W DIP Package- 1kVDC Isolation- Regulated Output- 4.5-9V, 9-18V, 18-36V, 36-72V Wide Input Range 2 : 1- UL94V-0 Package Material- Continuous Short Circiut Protection- Cost Effective- 100% Burned In- Efficiency to 84%
AD7416AR 10-Bit Digital Temperature Sensor (AD7416) and Single/Four-Channel ADC (AD7417/AD7418)
AD7416ARM 10-Bit Digital Temperature Sensor (AD7416) and Single/Four-Channel ADC (AD7417/AD7418)
AD7416ARM-REEL ECONOLINE: REC2.2-S_DR/H1 - 2.2W DIP Package- 1kVDC Isolation- Regulated Output- UL94V-0 Package Material- Continuous Short Circiut Protection- Internal SMD design- 100% Burned In- Efficiency to 75%
AD7416ARM-REEL7 ECONOLINE: REC2.2-S_DRW(Z)/H* - 2.2W DIP Package- 1kVDC Isolation- Regulated Output- 4.5-9V, 9-18V, 18-36V, 36-72V Wide Input Range 2 : 1- UL94V-0 Package Material- Continuous Short Circiut Protection- Cost Effective- 100% Burned In- Efficiency to 84%
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
AD7416ACHIPS 制造商:AD 制造商全稱:Analog Devices 功能描述:10-Bit Digital Temperature Sensor (AD7416) and Single/Four-Channel ADC (AD7417/AD7418)
AD7416AR 功能描述:IC SENSOR TEMP 10BIT 8-SOIC RoHS:否 類別:集成電路 (IC) >> PMIC - 熱管理 系列:- 標(biāo)準(zhǔn)包裝:2,500 系列:SilentSense™ 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:-55°C ~ 125°C,外部傳感器 精確度:±2°C 本地(最大),±3°C 遠(yuǎn)程(最大) 拓?fù)?ADC(三角積分型),比較器,寄存器庫 輸出類型:I²C?/SMBus? 輸出警報:是 輸出風(fēng)扇:是 電源電壓:2.7 V ~ 5.5 V 工作溫度:-55°C ~ 125°C 安裝類型:表面貼裝 封裝/外殼:8-TSSOP,8-MSOP(0.118",3.00mm 寬) 供應(yīng)商設(shè)備封裝:8-MSOP 包裝:帶卷 (TR) 其它名稱:MIC284-2BMMTRMIC284-2BMMTR-ND
AD7416ARM 功能描述:IC SENSOR TEMP 10BIT 8-MSOP RoHS:否 類別:集成電路 (IC) >> PMIC - 熱管理 系列:- 標(biāo)準(zhǔn)包裝:2,500 系列:SilentSense™ 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:-55°C ~ 125°C,外部傳感器 精確度:±2°C 本地(最大),±3°C 遠(yuǎn)程(最大) 拓?fù)?ADC(三角積分型),比較器,寄存器庫 輸出類型:I²C?/SMBus? 輸出警報:是 輸出風(fēng)扇:是 電源電壓:2.7 V ~ 5.5 V 工作溫度:-55°C ~ 125°C 安裝類型:表面貼裝 封裝/外殼:8-TSSOP,8-MSOP(0.118",3.00mm 寬) 供應(yīng)商設(shè)備封裝:8-MSOP 包裝:帶卷 (TR) 其它名稱:MIC284-2BMMTRMIC284-2BMMTR-ND
AD7416ARM-REEL 功能描述:IC SENSOR TEMP 10BIT 8-MSOP T/R RoHS:否 類別:集成電路 (IC) >> PMIC - 熱管理 系列:- 標(biāo)準(zhǔn)包裝:2,500 系列:SilentSense™ 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:-55°C ~ 125°C,外部傳感器 精確度:±2°C 本地(最大),±3°C 遠(yuǎn)程(最大) 拓?fù)?ADC(三角積分型),比較器,寄存器庫 輸出類型:I²C?/SMBus? 輸出警報:是 輸出風(fēng)扇:是 電源電壓:2.7 V ~ 5.5 V 工作溫度:-55°C ~ 125°C 安裝類型:表面貼裝 封裝/外殼:8-TSSOP,8-MSOP(0.118",3.00mm 寬) 供應(yīng)商設(shè)備封裝:8-MSOP 包裝:帶卷 (TR) 其它名稱:MIC284-2BMMTRMIC284-2BMMTR-ND
AD7416ARM-REEL7 功能描述:IC SENSOR TEMP 10BIT 8-MSOP T/R RoHS:否 類別:集成電路 (IC) >> PMIC - 熱管理 系列:- 標(biāo)準(zhǔn)包裝:2,500 系列:SilentSense™ 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:-55°C ~ 125°C,外部傳感器 精確度:±2°C 本地(最大),±3°C 遠(yuǎn)程(最大) 拓?fù)?ADC(三角積分型),比較器,寄存器庫 輸出類型:I²C?/SMBus? 輸出警報:是 輸出風(fēng)扇:是 電源電壓:2.7 V ~ 5.5 V 工作溫度:-55°C ~ 125°C 安裝類型:表面貼裝 封裝/外殼:8-TSSOP,8-MSOP(0.118",3.00mm 寬) 供應(yīng)商設(shè)備封裝:8-MSOP 包裝:帶卷 (TR) 其它名稱:MIC284-2BMMTRMIC284-2BMMTR-ND