參數(shù)資料
型號(hào): DAC8512
廠商: Analog Devices, Inc.
英文描述: +5 V, Serial Input Complete 12-Bit DAC(串行輸入完備的12位D/A轉(zhuǎn)換器)
中文描述: 5伏,串行輸入完整的12位DAC(串行輸入完備的12位的D / A轉(zhuǎn)換器)
文件頁數(shù): 9/20頁
文件大?。?/td> 771K
代理商: DAC8512
DAC8512
–9–
REV. A
APPLICATIONS SECTION
Power Supplies, Bypassing, and Grounding
All precision converter products require careful application of
good grounding practices to maintain full rated performance.
Because the DAC8512 has been designed for +5 V applications,
it is ideal for those applications under microprocessor or micro-
computer control. In these applications, digital noise is preva-
lent; therefore, special care must be taken to assure that its
inherent precision is maintained. This means that particularly
good engineering judgment should be exercised when address-
ing the power supply, grounding, and bypassing issues using the
DAC8512.
The power supply used for the DAC8512 should be well filtered
and regulated. The device has been completely characterized for
a +5 V supply with a tolerance of
±
5%. Since a +5 V logic sup-
ply is almost universally available, it is not recommended to
connect the DAC directly to an unfiltered logic supply without
careful filtering. Because it is convenient, a designer might be
inclined to tap a logic circuit’s supply for the DAC’s supply.
Unfortunately, this is not wise because fast logic with nanosec-
ond transition edges induce high current pulses. The high tran-
sient current pulses can generate glitches hundreds of millivolts
in amplitude due to wiring resistances and inductances. This
high frequency noise will corrupt the analog circuits internal to
the DAC and cause errors. Even though their spike noise is
lower in amplitude, directly tapping the output of a +5 V system
supply can cause errors because these supplies are of the switch-
ing regulator type that can and do generate a great deal of high
frequency noise. Therefore, the DAC and any associated analog
circuitry should be powered directly from the system power sup-
ply outputs using appropriate filtering. Figure 23 illustrates how
a clean, analog-grade supply can be generated from a +5 V logic
supply using a differential LC filter with separate power supply
and return lines. With the values shown, this filter can easily
handle 100 mA of load current without saturating the ferrite
cores. Higher current capacity can be achieved with larger ferrite
cores. For lowest noise, all electrolytic capacitors should be low
ESR (Equivalent Series Resistance) type.
100
μ
F
ELECT
.
10-22
μ
F
TANT.
0.1
μ
F
CER.
TTL/CMOS
LOGIC
CIRCUITS
+5V
POWER SUPPLY
+5V
+5V
RETURN
FERRITE BEADS:
2 TURNS, FAIR-RITE
#2677006301
Figure 23. Properly Filtering a +5 V Logic Supply Can Yield
a High Quality Analog Supply
In order to fit the DAC8512 in an 8-pin package, it was neces-
sary to use only one ground connection to the device. The
ground connection of the DAC serves as the return path for
supply currents as well as the reference point for the digital in-
put thresholds. The ground connection also serves as the supply
rail for the internal voltage reference and the output amplifier.
Therefore, to minimize any errors, it is recommended that
the ground connection of the DAC8512 be connected to a high
quality analog ground, such as the one described above. Gener-
ous bypassing of the DAC’s supply goes a long way in reducing
supply line-induced errors. Local supply bypassing consisting of
a 10
μ
F tantalum electrolytic in parallel with a 0.1
μ
F ceramic is
recommended. The decoupling capacitors should be connected
between the DAC’s supply pin (Pin 1) and the analog ground
(Pin 7). Figure 24 shows how the ground and bypass connec-
tions should be made to the DAC8512.
6
2
GND
7
V
DD
8
DAC8512
10
μ
F
0.1
μ
F
V
OUT
1
+5V
TO ANALOG GROUND
CS
CLR
5
3
4
LD
SCLK
SDI
V
OUT
Figure 24. Recommended Grounding and Bypassing
Scheme for the DAC8512
Unipolar Output Operation
This is the basic mode of operation for the DAC8512. As shown
in Figure 24, the DAC8512 has been designed to drive loads as
low as 2 k
in parallel with 500 pF. The code table for this op-
eration is shown in Table II.
10
μ
F
0.1
μ
F
0V
V
OUT
4.095V
+5V
2k
500pF
6
2
V
DD
8
DAC8512
1
CS
CLR
5
3
4
LD
SCLK
SDI
7
GND
V
OUT
Figure 25. Unipolar Output Operation
Table II. Unipolar Code Table
Hexadecimal Number
in DAC Register
Decimal Number
in DAC Register
Analog Output
Voltage (V)
FFF
801
800
7FF
000
4095
2049
2048
2047
0
+4.095
+2.049
+2.048
+2.047
0
Typical Performance Characteristics—
相關(guān)PDF資料
PDF描述
DAC8562 +5 V,Parallel Input Complete 12-Bit DAC(并行輸入完備的12位D/A轉(zhuǎn)換器)
DAC8841 8 BIT OCTAL 2-QUADRANT MULTIPLYING CMOS TRIM DAC
DAC902 12-Bit, 165MSPS DIGITAL-TO-ANALOG CONVERTER
DAC902E 12-Bit, 165MSPS DIGITAL-TO-ANALOG CONVERTER
DAC902U 12-Bit, 165MSPS DIGITAL-TO-ANALOG CONVERTER
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
DAC8512002S 制造商:Analog Devices 功能描述:
DAC8512-002S 制造商:Analog Devices 功能描述:
DAC8512EP 功能描述:IC DAC 12BIT SRL LP 5V 8-DIP RoHS:否 類別: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:Data Converter Fundamentals DAC Architectures 標(biāo)準(zhǔn)包裝:750 系列:- 設(shè)置時(shí)間:7µs 位數(shù):16 數(shù)據(jù)接口:并聯(lián) 轉(zhuǎn)換器數(shù)目:1 電壓電源:雙 ± 功率耗散(最大):100mW 工作溫度:0°C ~ 70°C 安裝類型:表面貼裝 封裝/外殼:28-LCC(J 形引線) 供應(yīng)商設(shè)備封裝:28-PLCC(11.51x11.51) 包裝:帶卷 (TR) 輸出數(shù)目和類型:1 電壓,單極;1 電壓,雙極 采樣率(每秒):143k
DAC8512EPZ 功能描述:IC DAC 12BIT SRL LP 5V 8DIP RoHS:是 類別: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:Data Converter Fundamentals DAC Architectures 標(biāo)準(zhǔn)包裝:750 系列:- 設(shè)置時(shí)間:7µs 位數(shù):16 數(shù)據(jù)接口:并聯(lián) 轉(zhuǎn)換器數(shù)目:1 電壓電源:雙 ± 功率耗散(最大):100mW 工作溫度:0°C ~ 70°C 安裝類型:表面貼裝 封裝/外殼:28-LCC(J 形引線) 供應(yīng)商設(shè)備封裝:28-PLCC(11.51x11.51) 包裝:帶卷 (TR) 輸出數(shù)目和類型:1 電壓,單極;1 電壓,雙極 采樣率(每秒):143k
DAC8512EZ 制造商:Rochester Electronics LLC 功能描述:- Bulk