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参数资料
| 型号： | AD9114BCPZRL7 |
| 厂商： | Analog Devices Inc |
| 文件页数： | 38/52页 |
| 文件大小： | 0K |
| 描述： | IC DAC DUAL 8BIT LO PWR 40LFCSP |
| 产品培训模块： | Data Converter Fundamentals DAC Architectures |
| 标准包装： | 750 |
| 系列： | TxDAC® |
| 位数： | 8 |
| 数据接口： | 串行 |
| 转换器数目： | 2 |
| 电压电源： | 模拟和数字 |
| 功率耗散（最大）： | 232mW |
| 工作温度： | -40°C ~ 85°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 40-VFQFN 裸露焊盘，CSP |
| 供应商设备封装： | 40-LFCSP-VQ（6x6） |
| 包装： | 带卷 (TR) |
| 输出数目和类型： | 4 电流，单极 |
| 采样率（每秒）： | 125M |
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Data Sheet
AD9114/AD9115/AD9116/AD9117
Rev. C | Page 43 of 52
REFERENCE OPERATION
The AD9114/AD9115/AD9116/AD9117 contains an internal
1.0 V band gap reference. The internal reference can be disabled by
setting Bit 0 (EXTREF) of the power-down register (Address 0x01)
through the SPI interface. To use the internal reference, decouple
the REFIO pin to AVSS with a 0.1 μF capacitor, enable the
internal reference, and clear Bit 0 of the power-down register
(Address 0x01) through the SPI interface. Note that this is the
default configuration. The internal reference voltage is present
at REFIO. If the voltage at REFIO is to be used anywhere else in
the circuit, an external buffer amplifier with an input bias current of
less than 100 nA must be used to avoid loading the reference. An
example of the use of the internal reference is shown in Figure 96.
CURRENT
SCALING
x32
AD9114/AD9115/
AD9116/AD9117
I DAC
OR
Q DAC
07466-
218
IxOUTFS
xRSET
0.1F
REFIO
IxREF
AVSS
FSADJx
VBG
1.0V
+
–
Figure 96. Internal Reference Configuration
REFIO serves as either an input or an output, depending on
whether the internal or an external reference is used. Table 17
summarizes the reference operation.
Table 17. Reference Operation
Reference Mode
REFIO Pin
Register Setting
Internal
Connect 0.1 F
capacitor
Register 0x01, Bit 0 = 0
(default)
External
Apply external
reference
Register 0x01, Bit 0 = 1
(for power saving)
An external reference can be used in applications requiring tighter
gain tolerances or lower temperature drift. In addition, a variable
external voltage reference can be used to implement a method
for gain control of the DAC output.
Recommendations When Using an External Reference
Apply the external reference to the REFIO pin. The internal
reference can be directly overdriven by the external reference,
or the internal reference can be powered down to save power
consumption.
The external 0.1 F compensation capacitor on REFIO is not
required unless specified by the external voltage reference
manufacturer. The input impedance of REFIO is 10 kΩ when
the internal reference is powered up and 1 MΩ when it is
powered down.
REFERENCE CONTROL AMPLIFIER
The AD9114/AD9115/AD9116/AD9117 contains a control
amplifier that regulates the full-scale output current, IxOUTFS.
The control amplifier is configured as a V-I converter, as shown
the VREFIO and an external resistor, xRSET, as stated in Equation 4 (see
segmented current sources with the proper scale factor to set
section).
The control amplifier allows a 10:1 adjustment span of IxOUTFS
from 2 mA to 20 mA by setting IxREF between 62.5 A and 625 A
(xRSET between 1.6 k and 16 k). When using a resistor larger
than 4 k, split the resistor with 4 k plus the additional
resistance needed, for example, 16 k made of a 4 k + 12 k
combination, and add a 1 F capacitor from 4 k to ground.
The wide adjustment span of IxOUTFS provides several benefits.
The first relates directly to the power dissipation of the
AD9114/AD9115/AD9116/AD9117, which is proportional to
benefit relates to the ability to adjust the output over a 8 dB
range with 0.25 dB steps, which is useful for controlling the
transmitted power. The small signal bandwidth of the reference
control amplifier is approximately 500 kHz. This allows the
device to be used for low frequency, small signal multiplying
applications.
DAC TRANSFER FUNCTION
The AD9114/AD9115/AD9116/AD9117 provides two differential
current outputs, IOUTP/IOUTN and QOUTP/ QOUTN. IOUTP
and QOUTP provide a near full-scale current output, IxOUTFS,
when all bits are high (that is, DAC CODE = 2N 1, where N = 8,
10, 12, or 14 for the AD9114, AD9115, AD9116, and AD9117,
respectively), while IOUTN and QOUTN, the complementary
outputs, provide no current. The current outputs appearing at the
positive DAC outputs, IOUTP and QOUTP, and at the negative
DAC outputs, IOUTN and QOUTN, are a function of both the
input code and IxOUTFS and can be expressed as follows:
IOUTP = (IDAC CODE/2N) × IIOUTFS
(1)
QOUTP = (QDAC CODE/2N) × IQOUTFS
IOUTN = ((2N 1) IDAC CODE)/2N × IIOUTFS
(2)
QOUTN = ((2N 1) QDAC CODE)/2N × IQOUTFS
where:
IDAC CODE and QDAC CODE = 0 to 2N 1 (that is, decimal
representation).
IIOUTFS and IQOUTFS are functions of the reference currents, IIREF
and IQREF, respectively, which are nominally set by a reference
voltage, VREFIO, and external resistors, IRSET and QRSET, respectively.
IIOUTFS and IQOUTFS can be expressed as follows:
IIOUTFS = 32 × IIREF
(3)
IQOUTFS = 32 × IQREF
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相关代理商/技术参数 |
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| AD9114-DPG2-EBZ | 功能描述:IC DAC DUAL 8BIT LO PWR 40LFCSP 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 |
| AD9114-EBZ | 制造商:Analog Devices 功能描述:DUAL 8 BIT LOW POWER CONVERTER - Boxed Product (Development Kits) |
| AD9115 | 制造商:AD 制造商全称:Analog Devices 功能描述:Dual, 8-/10-/12-/14-Bit Low Power Digital-to-Analog Converters |
| AD91151Z | 制造商:Analog Devices 功能描述: |
| AD91154Z | 制造商:Analog Devices 功能描述:SCREENED DSP PART - Rail/Tube |
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