欧美成人免费电影,国产欧美一区二区三区精品酒店,精品国产a毛片,色网在线免费观看

參數資料
型號: AD7888BRU
廠商: ANALOG DEVICES INC
元件分類: ADC
英文描述: +2.7 V to +5.25 V, Micropower, 8-Channel, 125 kSPS, 12-Bit ADC in 16-Lead TSSOP
中文描述: 8-CH 12-BIT SUCCESSIVE APPROXIMATION ADC, SERIAL ACCESS, PDSO16
封裝: TSSOP-16
文件頁數: 9/16頁
文件大小: 164K
代理商: AD7888BRU
REV. 0
AD7888
–9–
TYPICAL CONNECTION DIAGRAM
Figure 8 shows a typical connection diagram for the AD7888.
Both AGND pins are connected to the analog ground plane of
the system. V
REF
is connected to a well decoupled V
DD
pin to
provide an analog input range of 0 V to V
DD
. The conversion
result is output in a 16-bit word with four leading zeroes fol-
lowed by the MSB of the 12-bit result. For applications where
power consumption is of concern, the automatic power down at
the end of conversion should be used to improve power perfor-
mance. See Modes of Operation section of the data sheet.
DOUT
DIN
SCLK
CS
m
C/
m
P
AIN1
AIN2
AIN8
AGND
AGND
0.1
m
F
10
m
F
SUPPLY +2.7V
TO +5.25V
0V TO
REF IN/
REF OUT
INPUT
SERIAL
INTERFACE
REF IN/
REF OUT
AD7888
V
DD
Figure 8. Typical Connection Diagram
Analog Input
Figure 9 shows an equivalent circuit of the analog input structure
of the AD7888. The two diodes D1 and D2 provide ESD pro-
tection 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. 20 mA is
the maximum current these diodes can conduct without causing
irreversible damage to the part. However, it is worth noting that
a small amount of current (1 mA) being conducted into the
substrate due to an overvoltage on an unselected channel, can
cause inaccurate conversions on a selected channel. The capaci-
tor C1 in Figure 9 is typically about 4 pF and can primarily be
attributed to pin capacitance. The resistor R1 is a lumped com-
ponent made up of the on resistance of a multiplexer and a switch.
This resistor is typically about 100
. The capacitor C2 is the
ADC sampling capacitor and has a capacitance of 20 pF typically.
Note: The analog input capacitance seen when the track and
hold is in track mode is typically 38 pF, while in hold mode it is
typically 4 pF.
V
IN
V
DD
D2
R1
C1
4pF
CONVERSION PHASE – SWITCH OPEN
TRACK PHASE – SWITCH CLOSED
D1
C2
20pF
Figure 9. Equivalent Analog Input Circuit
For ac applications, removing high frequency components from
the analog input signal is recommended by use of an RC low-
pass filter on the relevant analog input pin. In applications
where harmonic distortion and signal to noise ratio are critical
the analog input should be driven from a low impedance source.
Large source impedances will significantly affect the ac perfor-
mance of the ADC. This may necessitate the use of an input
buffer amplifier. The choice of the op amp will be a function of
the particular application.
When no amplifier is used to drive the analog input the source
impedance should be limited to low values. The maximum
source impedance will depend on the amount of total harmonic
distortion (THD) that can be tolerated. The THD will increase
as the source impedance increases and performance will degrade.
Figure 10 shows a graph of the total harmonic distortion versus
analog input signal frequency for different source impedances.
INPUT FREQUENCY – kHz
–90
0.15
42.14
T
10.89
31.59
21.14
–85
–80
–75
–70
–65
49.86
THD vs. FREQUENCY FOR DIFFERENT
SOURCE IMPEDANCES
V
= +5V
5V EXT REFERENCE
R
IN
= 1k
V
, C
IN
= 100pF
R
IN
= 50
V
, C
IN
= 2.2nF
R
IN
= 10
V
, C
IN
= 10nF
Figure 10. THD vs. Analog Input Frequency
Analog Input Selection
On power-up, the default AIN selection is AIN1. When return-
ing to normal operation from power-down, the AIN selected
will be the same one that was selected prior to power-down
being initiated. Table II below shows the multiplexer address
corresponding to each analog input from AIN1 to AIN8 for the
AD7888.
Table II. Channel Configurations
ADD2
ADD1
ADD0
Analog Input Channel
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
AIN1
AIN2
AIN3
AIN4
AIN5
AIN6
AIN7
AIN8
On-Chip Reference
The AD7888 has an on-chip 2.5 V reference. This reference can
be enabled or disabled by clearing or setting the REF bit in the
Control Register, respectively. If the on-chip reference is to be
used externally in a system, it must be buffered before it is ap-
plied elsewhere. If an external reference is applied to the device,
the internal reference is automatically overdriven. However, in
相關PDF資料
PDF描述
AD7889 12-Bit 600 kSPS ADC(單電源600kSPS12位A/D轉換器)
AD7890AN-10 DIN Audio Connector; No. of Contacts:6; Contact Termination:Solder; Mounting Type:Panel; Gender:Female; Terminal Type:Solder RoHS Compliant: Yes
AD7890AR-4 Circular Connector Cable Assembly; Connector Type A:Circular Receptacle; Connector Type B:Stripped End Leads; Cable Length:10ft RoHS Compliant: Yes
AD7890BN-10 SECURITY GUARD BLACK LOCKDOWN
AD7890BN-2 Slide Switch; Circuitry:SPDT; Contact Current Max:4A; Switch Operation:On-On; Switch Terminals:Through Hole; Actuator Style:Vertical Flush; Leaded Process Compatible:Yes; Mounting Type:PCB; Switch Features:Vertical Flush Actuator RoHS Compliant: Yes
相關代理商/技術參數
參數描述
AD7888BRZ 功能描述:IC ADC 12BIT SRL 125KSPS 16SOIC RoHS:是 類別:集成電路 (IC) >> 數據采集 - 模數轉換器 系列:- 標準包裝:1,000 系列:- 位數:12 采樣率(每秒):300k 數據接口:并聯 轉換器數目:1 功率耗散(最大):75mW 電壓電源:單電源 工作溫度:0°C ~ 70°C 安裝類型:表面貼裝 封裝/外殼:24-SOIC(0.295",7.50mm 寬) 供應商設備封裝:24-SOIC 包裝:帶卷 (TR) 輸入數目和類型:1 個單端,單極;1 個單端,雙極
AD7889-1ACBZ-500R7 功能描述:IC ADC 12BIT CTRLR TOUCH 12WLCSP RoHS:是 類別:集成電路 (IC) >> 數據采集 - 觸摸屏控制器 系列:- 標準包裝:96 系列:- 類型:- 觸摸面板接口:- 輸入數/鍵:- 分辨率(位):- 評估套件:* 數據接口:- 數據速率/采樣率 (SPS,BPS):- 電壓基準:- 電源電壓:- 電流 - 電源:- 工作溫度:- 安裝類型:表面貼裝 封裝/外殼:16-TSSOP(0.173",4.40mm 寬) 供應商設備封裝:16-TSSOP 包裝:帶卷 (TR)
AD7889-1ACBZ-RL 功能描述:IC ADC 12BIT CTRLR TOUCH 12WLCSP RoHS:是 類別:集成電路 (IC) >> 數據采集 - 觸摸屏控制器 系列:- 標準包裝:96 系列:- 類型:- 觸摸面板接口:- 輸入數/鍵:- 分辨率(位):- 評估套件:* 數據接口:- 數據速率/采樣率 (SPS,BPS):- 電壓基準:- 電源電壓:- 電流 - 電源:- 工作溫度:- 安裝類型:表面貼裝 封裝/外殼:16-TSSOP(0.173",4.40mm 寬) 供應商設備封裝:16-TSSOP 包裝:帶卷 (TR)
AD7889-1ACBZ-RL7 功能描述:IC ADC 12BIT CTRLR TOUCH 12WLCSP RoHS:是 類別:集成電路 (IC) >> 數據采集 - 觸摸屏控制器 系列:- 標準包裝:96 系列:- 類型:- 觸摸面板接口:- 輸入數/鍵:- 分辨率(位):- 評估套件:* 數據接口:- 數據速率/采樣率 (SPS,BPS):- 電壓基準:- 電源電壓:- 電流 - 電源:- 工作溫度:- 安裝類型:表面貼裝 封裝/外殼:16-TSSOP(0.173",4.40mm 寬) 供應商設備封裝:16-TSSOP 包裝:帶卷 (TR)
AD7889ACBZ-500R7 功能描述:IC ADC 12BIT CTRLR TOUCH 12WLCSP RoHS:是 類別:集成電路 (IC) >> 數據采集 - 觸摸屏控制器 系列:- 標準包裝:96 系列:- 類型:- 觸摸面板接口:- 輸入數/鍵:- 分辨率(位):- 評估套件:* 數據接口:- 數據速率/采樣率 (SPS,BPS):- 電壓基準:- 電源電壓:- 電流 - 電源:- 工作溫度:- 安裝類型:表面貼裝 封裝/外殼:16-TSSOP(0.173",4.40mm 寬) 供應商設備封裝:16-TSSOP 包裝:帶卷 (TR)
主站蜘蛛池模板: 武夷山市| 盈江县| 资阳市| 谢通门县| 固镇县| 迁安市| 石家庄市| 临泉县| 东丰县| 新平| 贺州市| 防城港市| 将乐县| 肥乡县| 西林县| 偃师市| 镇巴县| 辰溪县| 疏勒县| 固阳县| 金阳县| 两当县| 南丰县| 邛崃市| 沙雅县| 卢龙县| 龙游县| 芦溪县| 夏津县| 石首市| 乃东县| 九寨沟县| 江达县| 富源县| 万山特区| 会宁县| 独山县| 沈丘县| 望江县| 屯门区| 小金县|