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(shù)資料
型號(hào): AD7846
廠商: Analog Devices, Inc.
英文描述: LC2MOS 16-Bit Voltage Output DAC
中文描述: LC2MOS 16位電壓輸出DAC
文件頁(yè)數(shù): 12/16頁(yè)
文件大?。?/td> 615K
代理商: AD7846
REV. E
–12–
AD7846
AD7846*
R/
W
+5V
DATA BUS
*LINEAR CIRCUITRY
OMITTED FOR CLARITY
CS
CLR
LDAC
DB0
DB15
MC68000
DS
DTACK
R/
W
A1
A23
ADDRESS
DECODE
ADDRESS BUS
D0
D15
Figure 25. AD7846-to-MC68000 Interface
DIGITAL FEEDTHROUGH
In the preceding interface configurations, most digital inputs to
the AD7846 are directly connected to the microprocessor bus.
Even when the device is not selected, these inputs will be con-
stantly changing. The high frequency logic activity on the bus
can feed through the DAC package capacitance to show up as
noise on the analog output. To minimize this Digital Feed-
through isolate the DAC from the noise source. Figure 26 shows
an interface circuit which isolates the DAC from the bus.
AD7846*
+5V
DATA BUS
*LINEAR CIRCUITRY
OMITTED FOR CLARITY
CS
LDAC
CLR
DB0
DB15
MICRO-
PROCESSOR
A1
A15
ADDRESS
DECODE
ADDRESS BUS
D0
D15
R/
W
R/
W
2
74LS245
B BUS
A BUS
DIR
G
Figure 26. AD7846 Interface Circuit Using Latches to Mini-
mize Digital Feedthrough
Note that to make use of the AD7846 readback feature using
the isolation technique of Figure 26, the latch needs to be
bidirectional.
APPLICATION HINTS
Noise
In high resolution systems, noise is often the limiting factor.
With a 10 volt span, a 16-bit LSB is 152
μ
V (–96 dB). Thus, the
noise floor must stay below –96 dB in the frequency range of
interest. Figure 7 shows the noise spectral density for the AD7846.
Grounding
As well as noise, the other prime consideration in high resolu-
tion DAC systems is grounding. With an LSB size of 152
μ
V
and a load current of 5 mA, 1 LSB of error can be introduced
by series resistance of only 0.03
.
Figure 27 below shows recommended grounding for the AD7846
in a typical application.
ANALOG SUPPLY
+15V
0V
DIGITAL SUPPLY
+5V DGND
15V
SIGNAL
GROUND
AD7846*
AD588*
R1
R4
R
L
V
(+5V TO
5V)
R2
R3
R5
*ADDITIONAL PINS
OMITTED FOR CLARITY
Figure 27. AD7846 Grounding
R1 to R5 represent lead and track resistances on the printed
circuit board. R1 is the resistance between the Analog Power
Supply ground and the Signal Ground. Since current flowing in
R1 is very low (bias current of AD588 sense amplifier), the
effect of R1 is negligible. R2 and R3 represent track resistance
between the AD588 outputs and the AD7846 reference inputs.
Because of the Force and Sense outputs on the AD588, these
resistances will also have a negligible effect on accuracy.
R4 is the resistance between the DAC output and the load. If
R
L
is constant, then R4 will introduce a gain error only which
can be trimmed out in the calibration cycle. R5 is the resistance
between the load and the analog common. If the output voltage
is sensed across the load, R5 will introduce a further gain error
which can be trimmed out. If, on the other hand, the output
voltage is sensed at the analog supply common, R5 appears as
part of the load and therefore introduces no errors.
Printed Circuit Board Layout
Figure 28 shows the AD7846 in a typical application with the
AD588 reference, producing an output analog voltage in the
±
10 volts range. Full scale and bipolar zero adjustment are
provided by potentiometers R2 and R3. Latches (2
×
74LS245)
isolate the DAC digital inputs from the active microprocessor
bus and minimize digital feedthrough.
The printed circuit board layout for Figure 28 is shown in Fig-
ures 29 and 30. Figure 29 is the component side layout while
Figure 30 is the solder side layout. The component overlay is
shown in Figure 31.
In the layout, the general grounding guidelines given in Figure
27 are followed. The AD588 and AD7846 are as close as pos-
sible, and the decoupling capacitors for these are also kept as
close to the device pins as possible.
相關(guān)PDF資料
PDF描述
AD7846AP LC2MOS 16-Bit Voltage Output DAC
AD7846AQ LC2MOS 16-Bit Voltage Output DAC
AD7846BP LC2MOS 16-Bit Voltage Output DAC
AD7846JN LC2MOS 16-Bit Voltage Output DAC
AD7846JP LC2MOS 16-Bit Voltage Output DAC
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
AD7846_10 制造商:AD 制造商全稱(chēng):Analog Devices 功能描述:LC2MOS 16-Bit Voltage Output DAC
AD7846ACHIPS 制造商:AD 制造商全稱(chēng):Analog Devices 功能描述:LC2MOS 16-Bit Voltage Output DAC
AD7846AP 功能描述:IC DAC 16BIT LC2MOS VOUT 28PLCC RoHS:否 類(lèi)別:集成電路 (IC) >> 數(shù)據(jù)采集 - 數(shù)模轉(zhuǎn)換器 系列:- 產(chǎn)品培訓(xùn)模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標(biāo)準(zhǔn)包裝:1,000 系列:- 設(shè)置時(shí)間:1µs 位數(shù):8 數(shù)據(jù)接口:串行 轉(zhuǎn)換器數(shù)目:8 電壓電源:雙 ± 功率耗散(最大):941mW 工作溫度:0°C ~ 70°C 安裝類(lèi)型:表面貼裝 封裝/外殼:24-SOIC(0.295",7.50mm 寬) 供應(yīng)商設(shè)備封裝:24-SOIC W 包裝:帶卷 (TR) 輸出數(shù)目和類(lèi)型:8 電壓,單極 采樣率(每秒):*
AD7846APZ 功能描述:IC DAC 16BIT LC2MOS VOUT 28-PLCC RoHS:是 類(lèi)別:集成電路 (IC) >> 數(shù)據(jù)采集 - 數(shù)模轉(zhuǎn)換器 系列:- 產(chǎn)品培訓(xùn)模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標(biāo)準(zhǔn)包裝:1,000 系列:- 設(shè)置時(shí)間:1µs 位數(shù):8 數(shù)據(jù)接口:串行 轉(zhuǎn)換器數(shù)目:8 電壓電源:雙 ± 功率耗散(最大):941mW 工作溫度:0°C ~ 70°C 安裝類(lèi)型:表面貼裝 封裝/外殼:24-SOIC(0.295",7.50mm 寬) 供應(yīng)商設(shè)備封裝:24-SOIC W 包裝:帶卷 (TR) 輸出數(shù)目和類(lèi)型:8 電壓,單極 采樣率(每秒):*
AD7846AQ 制造商:Rochester Electronics LLC 功能描述: 制造商:Analog Devices 功能描述:IC,D/A CONVERTER,SINGLE,16-BIT,BICMOS,DIP,28PIN
主站蜘蛛池模板: 于田县| 甘肃省| 柘荣县| 南阳市| 鄄城县| 礼泉县| 南溪县| 宁乡县| 永春县| 汾西县| 始兴县| 孟津县| 乌拉特前旗| 梅河口市| 观塘区| 卢氏县| 冕宁县| 巴林左旗| 兴文县| 芒康县| 观塘区| 正蓝旗| 五常市| 江陵县| 揭东县| 敦煌市| 哈密市| 抚顺县| 克山县| 绥棱县| 银川市| 屏东市| 波密县| 石棉县| 晋江市| 延长县| 绩溪县| 屏东市| 孙吴县| 新丰县| 综艺|