参数资料
| 型号： | AD9754ARUZRL7 |
| 厂商： | Analog Devices Inc |
| 文件页数： | 6/24页 |
| 文件大小： | 0K |
| 描述： | IC DAC 14BIT 125MSPS 28-TSSOP |
| 产品培训模块： | Data Converter Fundamentals DAC Architectures |
| 标准包装： | 1,000 |
| 系列： | TxDAC® |
| 设置时间： | 35ns |
| 位数： | 14 |
| 数据接口： | 并联 |
| 转换器数目： | 1 |
| 电压电源： | 模拟和数字 |
| 功率耗散（最大）： | 220mW |
| 工作温度： | -40°C ~ 85°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 28-TSSOP（0.173"，4.40mm 宽） |
| 供应商设备封装： | 28-TSSOP |
| 包装： | 带卷 (TR) |
| 输出数目和类型： | 1 电流，单极；1 电流，双极 |
| 采样率（每秒）： | 125M |
| 其它名称： | AD9754ARUZRL7-ND AD9754ARUZRL7TR |
AD9754
–14–
REV. A
APPLYING THE AD9754
OUTPUT CONFIGURATIONS
The following sections illustrate some typical output configura-
tions for the AD9754. Unless otherwise noted, it is assumed
that IOUTFS is set to a nominal 20 mA. For applications requir-
ing the optimum dynamic performance, a differential output
configuration is suggested. A differential output configuration
may consist of either an RF transformer or a differential op amp
configuration. The transformer configuration provides the opti-
mum high frequency performance and is recommended for any
application allowing for ac coupling. The differential op amp
configuration is suitable for applications requiring dc coupling, a
bipolar output, signal gain and/or level shifting.
A single-ended output is suitable for applications requiring a
unipolar voltage output. A positive unipolar output voltage will
result if IOUTA and/or IOUTB is connected to an appropri-
ately sized load resistor, RLOAD, referred to ACOM. This con-
figuration may be more suitable for a single-supply system
requiring a dc coupled, ground referred output voltage. Alterna-
tively, an amplifier could be configured as an I-V converter, thus
converting IOUTA or IOUTB into a negative unipolar voltage.
This configuration provides the best dc linearity since IOUTA
or IOUTB is maintained at a virtual ground. Note, IOUTA
provides slightly better performance than IOUTB.
DIFFERENTIAL COUPLING USING A TRANSFORMER
An RF transformer can be used to perform a differential-to-
single-ended signal conversion as shown in Figure 27. A
differentially coupled transformer output provides the optimum
distortion performance for output signals whose spectral content
lies within the transformer’s passband. An RF transformer such
as the Mini-Circuits T1-1T provides excellent rejection of
common-mode distortion (i.e., even-order harmonics) and noise
over a wide frequency range. It also provides electrical isolation
and the ability to deliver twice the power to the load. Trans-
formers with different impedance ratios may also be used for
impedance matching purposes. Note that the transformer
provides ac coupling only.
RLOAD
AD9754
22
21
MINI-CIRCUITS
T1-1T
OPTIONAL RDIFF
IOUTA
IOUTB
Figure 27. Differential Output Using a Transformer
The center tap on the primary side of the transformer must be
connected to ACOM to provide the necessary dc current path
for both IOUTA and IOUTB. The complementary voltages
appearing at IOUTA and IOUTB (i.e., VOUTA and VOUTB)
swing symmetrically around ACOM and should be maintained
with the specified output compliance range of the AD9754. A
differential resistor, RDIFF, may be inserted in applications in
which the output of the transformer is connected to the load,
RLOAD, via a passive reconstruction filter or cable. RDIFF is deter-
mined by the transformer’s impedance ratio and provides the
proper source termination that results in a low VSWR. Note
that approximately half the signal power will be dissipated
across RDIFF.
DIFFERENTIAL USING AN OP AMP
An op amp can also be used to perform a differential-to-single-
ended conversion as shown in Figure 28. The AD9754 is con-
figured with two equal load resistors, RLOAD, of 25
. The
differential voltage developed across IOUTA and IOUTB is
converted to a single-ended signal via the differential op amp
configuration. An optional capacitor can be installed across
IOUTA and IOUTB, forming a real pole in a low-pass filter.
The addition of this capacitor also enhances the op amp’s dis-
tortion performance by preventing the DAC’s high slewing
output from overloading the op amp’s input.
The common-mode rejection of this configuration is typically
determined by the resistor matching. In this circuit, the differ-
ential op amp circuit is configured to provide some additional
signal gain. The op amp must operate from a dual supply since
its output is approximately
±1.0 V. A high speed amplifier such
as the AD8055 or AD9632 capable of preserving the differential
AD9754
22
IOUTA
IOUTB 21
COPT
500
225
500
25
AD8055
Figure 28. DC Differential Coupling Using an Op Amp
performance of the AD9754 while meeting other system level
objectives (i.e., cost, power) should be selected. The op amps
differential gain, its gain setting resistor values and full-scale
output swing capabilities should all be considered when opti-
mizing this circuit.
The differential circuit shown in Figure 29 provides the neces-
sary level-shifting required in a single supply system. In this
case, AVDD, which is the positive analog supply for both the
AD9754 and the op amp, is also used to level-shift the differ-
ential output of the AD9754 to midsupply (i.e., AVDD/2). The
AD8041 is a suitable op amp for this application.
AD9754
22
IOUTA
IOUTB 21
COPT
500
225
1k
25
AD8041
1k
AVDD
Figure 29. Single-Supply DC Differential Coupled Circuit
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相关代理商/技术参数 |
参数描述 |
|---|---|
| AD9754ARZ | 功能描述:IC DAC 14BIT 125MSPS 28-SOIC RoHS:是 类别:集成电路 (IC) >> 数据采集 - 数模转换器 系列:TxDAC® 标准包装:1 系列:- 设置时间:4.5µs 位数:12 数据接口:串行，SPI? 转换器数目:1 电压电源:单电源 功率耗散（最大）:- 工作温度:-40°C ~ 125°C 安装类型:表面贴装 封装/外壳:8-SOIC（0.154"，3.90mm 宽） 供应商设备封装:8-SOICN 包装:剪切带 (CT) 输出数目和类型:1 电压，单极；1 电压，双极 采样率（每秒）:* 其它名称:MCP4921T-E/SNCTMCP4921T-E/SNRCTMCP4921T-E/SNRCT-ND |
| AD9754ARZ | 制造商:Analog Devices 功能描述:IC 14BIT DAC POLY FUSE SMD 9754 |
| AD9754ARZRL | 功能描述:IC DAC 14BIT 125MSPS 28-SOIC TR RoHS:是 类别:集成电路 (IC) >> 数据采集 - 数模转换器 系列:TxDAC® 标准包装:47 系列:- 设置时间:2µs 位数:14 数据接口:并联 转换器数目:1 电压电源:单电源 功率耗散（最大）:55µW 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:28-SSOP（0.209"，5.30mm 宽） 供应商设备封装:28-SSOP 包装:管件 输出数目和类型:1 电流，单极；1 电流，双极 采样率（每秒）:* |
| AD9754-EB | 制造商:Analog Devices 功能描述:Evaluation Board For AD9754 制造商:Analog Devices 功能描述:DEV TOOLS, EVAL BD FOR AD9754 - Bulk |
| AD9754-EBZ | 功能描述:BOARD EVAL FOR AD9754 RoHS:是 类别:编程器，开发系统 >> 评估板 - 数模转换器 (DAC) 系列:TxDAC® 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:1 系列:- DAC 的数量:4 位数:12 采样率（每秒）:- 数据接口:串行，SPI? 设置时间:3µs DAC 型:电流/电压 工作温度:-40°C ~ 85°C 已供物品:板 已用 IC / 零件:MAX5581 |
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