參數(shù)資料
型號: AD667JN
廠商: ANALOG DEVICES INC
元件分類: DAC
英文描述: Microprocessor-Compatible 12-Bit D/A Converter
中文描述: PARALLEL, WORD INPUT LOADING, 3 us SETTLING TIME, 12-BIT DAC, PDIP28
封裝: PLASTIC, DIP-28
文件頁數(shù): 6/8頁
文件大?。?/td> 327K
代理商: AD667JN
AD667
REV. A
–6–
Small resistors may be added to the feedback resistors in order
to accomplish small modifications in the scaling. For example, if
a 10.24 V full scale is desired, a 140
1% low TC metal-film
resistor can be added in series with the internal (nominal) 5k
feedback resistor, and the gain trim potentiometer (between
Pins 6 and 7) should be increased to 200
. In the bipolar
mode, increase the value of the bipolar offset trim potentiometer
also to 200
.
GROUNDING RULES
The AD667 brings out separate analog and power grounds to
allow optimum connections for low noise and high speed perfor-
mance. These grounds should be tied together at one point,
usually the device power ground. The separate ground returns
are provided to minimize current flow in low level signal paths.
The analog ground at Pin 5 is the ground point for the output
amplifier and is thus the “high quality” ground for the AD667;
it should be connected directly to the analog reference point of
the system. The power ground at Pin 16 can be connected to
the most convenient ground point; analog power return is
preferred. If power ground contains high frequency noise be-
yond 200 mV, this noise may feed through the converter, thus
some caution will be required in applying these grounds.
It is also important to apply decoupling capacitors properly on
the power supplies for the AD667 and the output amplifier. The
correct method for decoupling is to connect a capacitor from
each power supply pin of the AD667 to the analog ground pin
of the AD667. Any load driven by the output amplifier should
also be referred to the analog ground pin.
OPTIMIZING SETTLING TIME
The dynamic performance of the AD667’s output amplifier can
be optimized by adding a small (20 pF) capacitor across the
feedback resistor. Figure 4 shows the improvement in both
large-signal and small-signal settling for the 10 V range. In Fig-
ure 4a, the top trace shows the data inputs (DB11–DB0 tied to-
gether), the second trace shows the CS pulse (A3–A0 tied low),
and the lower two traces show the analog outputs for C
F
= 0 pF
and 20 pF respectively.
Figures 4b and 4c show the settling time for the transition from
all bits on to all bits off. Note that the settling time to
±
1/2 LSB
for the 10 V step is improved from 2.4 microseconds to 1.6 mi-
croseconds by the addition of the 20 pF capacitor.
Figures 4d and 4e show the settling time for the transition from
all bits off to all bits on. The improvement in settling time
gained by adding C
C
= 20 pF is similar.
a. Large Scale Settling
b. Fine-Scale Settling, C
F
= 0 pF
c. Fine-Scale Settling, C
F
= 20 pF
d. Fine-Scale Settling, C
F
= 0 pF
e. Fine-Scale Settling, C
F
= 20 pF
Figure 4. Settling Time Performance
DIGITAL CIRCUIT DETAILS
The bus interface logic of the AD667 consists of four indepen-
dently addressable registers in two ranks. The first rank consists
of three four-bit registers which can be loaded directly from a
4-, 8-, 12-, or 16-bit microprocessor bus. Once the complete
12-bit data word has been assembled in the first rank, it can be
loaded into the 12-bit register of the second rank. This
double-buffered organization avoids the generation of spurious
analog output values. Figure 5 shows the block diagram of the
AD667 logic section.
The latches are controlled by the address inputs, A0–A3, and
the
CS
input. All control inputs are active low, consistent with
general practice in microprocessor systems. The four address
lines each enable one of the four latches, as indicated in Table II.
All latches in the AD667 are level-triggered. This means that
data present during the time when the control signals are valid
will enter the latch. When any one of the control signals returns
high, the data is latched.
相關PDF資料
PDF描述
AD667JP Microprocessor-Compatible 12-Bit D/A Converter
AD667KN Microprocessor-Compatible 12-Bit D/A Converter
AD667KP Microprocessor-Compatible 12-Bit D/A Converter
AD668A 12-Bit Ultrahigh Speed Multiplying D/A Converter
AD668AQ 12-Bit Ultrahigh Speed Multiplying D/A Converter
相關代理商/技術(shù)參數(shù)
參數(shù)描述
AD667JN 制造商:Analog Devices 功能描述:SEMICONDUCTORSLINEAR
AD667JN/+ 制造商:Analog Devices 功能描述:DAC 1CH CURRENT STEERING 12-BIT 28PDIP W - Rail/Tube 制造商:Rochester Electronics LLC 功能描述:IC - 12-BIT D/A CONVERTER - Bulk
AD667JNZ 功能描述:IC DAC 12BIT W/BUFF LATCH 28-DIP 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)品培訓模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標準包裝:50 系列:- 設置時間:4µs 位數(shù):12 數(shù)據(jù)接口:串行 轉(zhuǎn)換器數(shù)目:2 電壓電源:單電源 功率耗散(最大):- 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:8-TSSOP,8-MSOP(0.118",3.00mm 寬) 供應商設備封裝:8-uMAX 包裝:管件 輸出數(shù)目和類型:2 電壓,單極 采樣率(每秒):* 產(chǎn)品目錄頁面:1398 (CN2011-ZH PDF)
AD667JP 功能描述:IC DAC 12BIT V-OUT 28-PLCC 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)品培訓模塊:Data Converter Fundamentals DAC Architectures 標準包裝:750 系列:- 設置時間: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) 供應商設備封裝: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
AD667JP-REEL 功能描述:數(shù)模轉(zhuǎn)換器- DAC MPU-Compatible IC 12-BIT RoHS:否 制造商:Analog Devices 轉(zhuǎn)換器數(shù)量:4 DAC 輸出端數(shù)量:4 轉(zhuǎn)換速率: 分辨率:12 bit 接口類型:Serial (I2C) 穩(wěn)定時間: 最大工作溫度:+ 105 C 安裝風格: 封裝 / 箱體:TSSOP 封裝:Reel