參數(shù)資料
型號(hào): XE8000EV121
廠商: Semtech
文件頁(yè)數(shù): 30/53頁(yè)
文件大?。?/td> 0K
描述: BOARD EVAL FOR SX8723/24
標(biāo)準(zhǔn)包裝: 1
主要目的: 接口,傳感器至模數(shù)轉(zhuǎn)換器接口,可編程
嵌入式:
已用 IC / 零件: SX8723,SX8724,SX8725
主要屬性: 用于橋型傳感器的信號(hào)調(diào)節(jié)
次要屬性: GUI,最多 16 位,1/12 ~ 1000 可編程增益,I2C 接口
已供物品: 板,CD
產(chǎn)品目錄頁(yè)面: 585 (CN2011-ZH PDF)
相關(guān)產(chǎn)品: SX8725E083DKR-ND - IC DAS PRESSURE/TEMP SENS 12MLPD
SX8724E082DKR-ND - IC DAS PRESSURE/TEMP SENS 16MLPQ
SX8725E083CT-ND - IC DAS PRESSURE/TEMP SENS 12MLPD
SX8724E082CT-ND - IC DAS PRESSURE/TEMP SENS 16MLPQ
SX8725E083TR-ND - IC DAS PRESSURE/TEMP SENS 12MLPD
SX8724E082TR-ND - IC DAS PRESSURE/TEMP SENS 16MLPQ
ADVANCED COMMUNICATIONS & SENSING
V1.23 2009 Semtech Corp.
www.semtech.com
36
SX8724
ZoomingADC for Pressure and Temperature Sensing
Switched Capacitor Principle
Basically, a switched capacitor is a way to emulate a resistor by using a capacitor. The capacitors are much
easier to realize on CMOS technologies and they show a very good matching precision.
Figure 19 - The Switched Capacitor Principle
A resistor is characterized by the current that flows through it (positive current leaves node V1):
R
V
I
2
1
=
(A)
Equation 22
One can verify that the mean current leaving node V1 with a capacitor switched at frequency f is:
(
) C
f
V
I
=
2
1
(A)
Equation 23
Therefore as a mean value, the switched capacitor
C
f
1
is equivalent to a resistor.
It is important to consider that this is only a mean value. If the current is not integrated (low impedance source),
the impedance is infinite during the whole time but the transition.
What does it mean for the ZoomingADC?
If the fs clock is reduced, the mean impedance is increased. By dividing the fs clock by a factor 10, the
impedance is increased by a factor 10.
One can reduce the capacitor that is switched by using an amplifier set to its minimal gain. In particular if PGA1
is used with gain 1, its mean impedance is 10x bigger than when it is used with gain 10.
Figure 20 - The Switched Capacitor Principle
One can increase the effective impedance by increasing the electrical bandwidth of the sensor node so that the
switching current is absorbed through the sensor before the switching period is over. Measuring the sensor
node will show short voltage spikes at the frequency fs, but these will not influence the measurement. Whereas
if the bandwidth of the node is lower, no spikes will arise, but a small offset can be generated by the integration
of the charges generated by the switched capacitors, this corresponds to the mean impedance effect.
Note:
One can increase the mean input impedance of the ZoomingADC by lowering the acquisition clock fs.
One can increase the mean input impedance of the ZoomingADC by decreasing the gain of the first enabled amplifier.
One can increase the effective input impedance of the ZoomingADC by having a source with a high electrical bandwidth (sensor electrical
bandwidth much higher than fs).
Sensor
C
ZoomingADC (model)
V
1
f
V
2
Sensor
impedence
Node
Capacitance
Current
integration
V
1
V
2
R
V
1
f
V
2
相關(guān)PDF資料
PDF描述
NR4012T330M INDUCTOR 33UH 20% SMD
NR4012T4R7N INDUCTOR WOUND 4.7UH 960MA SMD
NR4012T2R2N INDUCTOR WOUND 2.2UH 1.2A SMD
NR4012T4R7M INDUCTOR 4.7UH 20% SMD
NR4012T470M INDUCTOR 47UH 20% SMD
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
XE8000MP 功能描述:PROG BOARD AND PROSTART2 CARD RoHS:否 類別:編程器,開(kāi)發(fā)系統(tǒng) >> 獨(dú)立編程器 系列:- 產(chǎn)品目錄繪圖:CHIPPROG-G4 標(biāo)準(zhǔn)包裝:1 系列:- 類型:成組編程器 適用于相關(guān)產(chǎn)品:EEPROM,EPROM,F(xiàn)LASH,MCU,NVRAM,PLD 所含物品:編程器,線纜,CD 產(chǎn)品目錄頁(yè)面:598 (CN2011-ZH PDF) 相關(guān)產(chǎn)品:AE-TS56-16I-3-ND - ISP CABLEADAPTER 14-PIN HEADERAE-TS40N-ND - ADAPTER SOCKET 40-TSOP TO 40-DIPAE-TS32N-ND - ADAPTER SOCKET 32-TSOP TO 32-DIPAE-TS28-ND - ADAPTER SOCKET 28-TSOP TO 28-DIPAE-T44-P16-ND - ADAPTER SOCKET 44-QFP TO 40-DIPAE-T44-I51/505-ND - ADAPTER SOCKET 44-QFP TO 40-DIPAE-SS56-16I-ND - ADAPTER SOCKET 56-SSOP TO 40-DIPAE-SP8U-ND - ADAPTER SOCKET 8-SSOP TO 8-DIPAE-SP28U2-ND - ADAPTER SOCKET 28-SSOP TO 28-DIPAE-SP28U1-ND - ADAPTER SOCKET 28-SSOP TO 28-DIP更多...
XE8801A 制造商:SEMTECH 制造商全稱:Semtech Corporation 功能描述:Data Acquisition with ZoomingADC?
XE8801AMI000WP 功能描述:SENSING MACHINE WITH 16 + 10 BIT RoHS:否 類別:集成電路 (IC) >> 嵌入式 - 微控制器 - 特定應(yīng)用 系列:XE880x 產(chǎn)品變化通告:Product Discontinuation 26/Aug/2009 標(biāo)準(zhǔn)包裝:250 系列:- 應(yīng)用:網(wǎng)絡(luò)處理器 核心處理器:4Kc 程序存儲(chǔ)器類型:- 控制器系列:- RAM 容量:16K x 8 接口:以太網(wǎng),UART,USB 輸入/輸出數(shù):- 電源電壓:1.8V, 3.3V 工作溫度:- 安裝類型:表面貼裝 封裝/外殼:208-LQFP 包裝:帶卷 (TR) 供應(yīng)商設(shè)備封裝:PG-LQFP-208 其它名稱:SP000314382
XE8801AMI027LF 功能描述:IC DAS 16BIT FLASH 8K MTP 44LQFP RoHS:是 類別:集成電路 (IC) >> 嵌入式 - 微控制器 - 特定應(yīng)用 系列:XE880x 產(chǎn)品變化通告:Product Discontinuation 26/Aug/2009 標(biāo)準(zhǔn)包裝:250 系列:- 應(yīng)用:網(wǎng)絡(luò)處理器 核心處理器:4Kc 程序存儲(chǔ)器類型:- 控制器系列:- RAM 容量:16K x 8 接口:以太網(wǎng),UART,USB 輸入/輸出數(shù):- 電源電壓:1.8V, 3.3V 工作溫度:- 安裝類型:表面貼裝 封裝/外殼:208-LQFP 包裝:帶卷 (TR) 供應(yīng)商設(shè)備封裝:PG-LQFP-208 其它名稱:SP000314382
XE8802 制造商:SEMTECH 制造商全稱:Semtech Corporation 功能描述:Sensing Machine Data Acquisition MCU