參數資料
型號: AD9742
廠商: Analog Devices, Inc.
英文描述: 12-Bit, 165 MSPS TxDAC D/A Converter
中文描述: 12位,165 MSPS的TxDAC系列D / A轉換
文件頁數: 11/20頁
文件大小: 783K
代理商: AD9742
REV. 0
AD9742
–11–
IOUTA and IOUTB also have a negative and positive voltage
compliance range that must be adhered to in order to achieve
optimum performance. The negative output compliance range of
–1.0 V is set by the breakdown limits of the CMOS process.
Operation beyond this maximum limit may result in a breakdown
of the output stage and affect the reliability of the AD9742.
The positive output compliance range is slightly dependent on the
full-scale output current, I
OUTFS
. It degrades slightly from its
nominal 1.2 V for an I
OUTFS
= 20 mA to 1.0 V for an I
OUTFS
= 2 mA.
The optimum distortion performance for a single-ended or differ-
ential output is achieved when the maximum full-scale signal at
IOUTA and IOUTB does not exceed 0.5 V.
DIGITAL INPUTS
The AD9742’s digital section consists of 12 input bit channels
and a clock input. The 12-bit parallel data inputs follow stan-
dard positive binary coding where DB11 is the most significant
bit (MSB) and DB0 is the least significant bit (LSB). IOUTA
produces a full-scale output current when all data bits are at
Logic 1. IOUTB produces a complementary output with the
full-scale current split between the two outputs as a function of
the input code.
DVDD
DIGITAL
INPUT
Figure 6. Equivalent Digital Input
The digital interface is implemented using an edge-triggered master/
slave latch. The DAC output updates on the rising edge of the clock
and is designed to support a clock rate as high as 165 MSPS. The
clock can be operated at any duty cycle that meets the specified
latch pulsewidth. The setup and hold times can also be varied
within the clock cycle as long as the specified minimum times are
met, although the location of these transition edges may affect
digital feedthrough and distortion performance. Best performance
is typically achieved when the input data transitions on the falling
edge of a 50% duty cycle clock.
DAC TIMING
Input Clock and Data Timing Relationship
Dynamic performance in a DAC is dependent on the relation-
ship between the position of the clock edges and the point in
time at which the input data changes. The AD9742 is rising
edge triggered, and so exhibits dynamic performance sensitivity
when the data transition is close to this edge. In general, the
goal when applying the AD9742 is to make the data transition
close to the falling clock edge. This becomes more important as
the sample rate increases. Figure 7 shows the relationship of
SFDR to clock placement with different sample rates. Note that
at the lower sample rates, more tolerance is allowed in clock
placement, while at higher rates, more care must be taken.
–3
–2
2
–1
0
1
70
80
TIME (ns) OF DATA CHANGE RELATIVE
TO RISING CLOCK EDGE
S
3
60
50
40
65
75
55
45
f
OUT
= 50MHz
f
OUT
= 20MHz
Figure 7. SFDR vs. Clock Placement @ f
OUT
= 20 MHz
and 50 MHz
Sleep Mode Operation
The AD9742 has a power-down function that turns off the
output current and reduces the supply current to less than 4 mA
over the specified supply range of 3.0 V to 3.6 V and tempera-
ture range. This mode can be activated by applying a logic level
1 to the SLEEP pin. The SLEEP pin logic threshold is equal to
0.5
AVDD. This digital input also contains an active pull-
down circuit that ensures the AD9742 remains enabled if this
input is left disconnected. The AD9742 takes less than 50 ns to
power down and approximately 5
m
s to power back up.
POWER DISSIPATION
The power dissipation, P
D
, of the AD9742 is dependent on
several factors that include:
The power supply voltages (AVDD and DVDD)
The full-scale current output I
OUTFS
The update rate f
CLOCK
The reconstructed digital input waveform
The power dissipation is directly proportional to the analog
supply current, I
AVDD
, and the digital supply current, I
DVDD
.
I
AVDD
is directly proportional to I
OUTFS
as shown in Figure 8
and is insensitive to f
CLOCK
. Conversely, I
DVDD
is dependent on
both the digital input waveform, f
CLOCK
, and digital supply
DVDD. Figure 9 shows I
DVDD
as a function of full-scale sine
wave output ratios (f
OUT
/f
CLOCK
) for various update rates with
DVDD = 3.3 V.
相關PDF資料
PDF描述
AD9742-EB 12-Bit, 165 MSPS TxDAC D/A Converter
AD9742AR 12-Bit, 165 MSPS TxDAC D/A Converter
AD9742ARU 12-Bit, 165 MSPS TxDAC D/A Converter
AD9744ARURL7 14-Bit, 165 MSPS TxDAC D/A Converter
AD9744 14-Bit, 165 MSPS TxDAC D/A Converter
相關代理商/技術參數
參數描述
AD9742ACP 制造商:Analog Devices 功能描述:DAC 1-CH Segment 12-bit 32-Pin LFCSP EP 制造商:Rochester Electronics LLC 功能描述:12-BIT 165 MSPS TXDAC D/A CONVERTER - Bulk 制造商:Analog Devices 功能描述:IC 12-BIT DAC
AD9742ACP-PCB 制造商:Analog Devices 功能描述:EVAL BD FOR AD9742 12BIT, 165MSPS TXDAC D/A CNVRTR - Bulk
AD9742ACP-PCBZ 功能描述:BOARD EVAL FOR AD9742ACP RoHS:是 類別:編程器,開發(fā)系統 >> 評估板 - 數模轉換器 (DAC) 系列:TxDAC® 產品培訓模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標準包裝:1 系列:- DAC 的數量:4 位數:12 采樣率(每秒):- 數據接口:串行,SPI? 設置時間:3µs DAC 型:電流/電壓 工作溫度:-40°C ~ 85°C 已供物品:板 已用 IC / 零件:MAX5581
AD9742ACPRL7 制造商:Analog Devices 功能描述:DAC 1-CH Segment 12-bit 32-Pin LFCSP EP T/R 制造商:Rochester Electronics LLC 功能描述:12-BIT 165 MSPS TXDAC D/A CONVERTER - Bulk
AD9742ACPZ 功能描述:IC DAC 12BIT 210MSPS 32LFCSP RoHS:是 類別:集成電路 (IC) >> 數據采集 - 數模轉換器 系列:TxDAC® 產品培訓模塊:Data Converter Fundamentals DAC Architectures 標準包裝:750 系列:- 設置時間:7µs 位數:16 數據接口:并聯 轉換器數目: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) 輸出數目和類型:1 電壓,單極;1 電壓,雙極 采樣率(每秒):143k