参数资料
| 型号： | AD5443YRM |
| 厂商： | Analog Devices Inc |
| 文件页数： | 11/25页 |
| 文件大小： | 0K |
| 描述： | IC DAC 12BIT SERIAL IOUT 10-MSOP |
| 产品培训模块： | Data Converter Fundamentals DAC Architectures |
| 设计资源： | Unipolar, Precision DC Digital-to-Analog Conversion Using AD5426/32/43 8-Bit to12-Bit DACs (CN0034) Precision, Bipolar Configuration for the AD5426/32/43 8-Bit to12-Bit DACs (CN0036) AC Signal Processing Using AD5426/32/43 Current Output DACs (CN0037) Programmable Gain Element Using AD5426/32/43 Current Output DACs (CN0038) Single-Ended-to-Differential Converters for Voltage Output and Current Output DACs Using AD8042 (CN0143) |
| 标准包装： | 50 |
| 位数： | 12 |
| 数据接口： | 串行 |
| 转换器数目： | 1 |
| 电压电源： | 单电源 |
| 工作温度： | -40°C ~ 125°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 10-TFSOP，10-MSOP（0.118"，3.00mm 宽） |
| 供应商设备封装： | 10-MSOP |
| 包装： | 管件 |
| 输出数目和类型： | 2 电流，单极；2 电流，双极 |
| 采样率（每秒）： | 2.5M |
| 配用： | EVAL-AD5443-DBRDZ-ND - BOARD EVAL CARD CLINUX/STAMP |
AD5426/AD5432/AD5443
Data Sheet
Rev. G | Page 18 of 24
ADDING GAIN
In applications where the output voltage is required to be greater
than VIN, gain can be added with an additional external amplifier or
it can be achieved in a single stage. It is important to consider the
effect of temperature coefficients of the thin film resistors of the
DAC. Simply placing a resistor in series with the RFB resistor causes
mismatches in the temperature coefficients, resulting in larger
gain temperature coefficient errors. Instead, the circuit shown
in Figure 46 is a recommended method of increasing the gain of
the circuit. R1, R2, and R3 should all have similar temperature
coefficients, but they need not match the temperature coefficients
of the DAC. This approach is recommended in circuits where
gains of greater than 1 are required.
R1
R3
R2
VIN
R1 = R2R3
R2 + R3
GAIN = R2 + R3
R2
NOTES
1. ADDITIONAL PINS OMITTED FOR CLARITY.
2. C1 PHASE COMPENSATION (1pF TO 2pF) MAY BE REQUIRED
IF A1 IS A HIGH SPEED AMPLIFIER.
VOUT
GND
IOUT2
IOUT1
RFB
A1
VREF
VDD
C1
03162-047
Figure 46. Increasing Gain of Current Output DAC
DACS USED AS A DIVIDER OR PROGRAMMABLE
GAIN ELEMENT
Current-steering DACs are very flexible and lend themselves to
many different applications. If this type of DAC is connected as
the feedback element of an op amp and RFB is used as the input
resistor as shown in Figure 47, then the output voltage is inversely
proportional to the digital input fraction, D.
For D = 1 2n the output voltage is
VOUT = VIN/D = VIN/(1 2N)
As D is reduced, the output voltage increases. For small values
of D, it is important to ensure that the amplifier does not saturate
and also that the required accuracy is met. For example, an 8-bit
DAC driven with the binary code 0x10 (00010000), that is, 16
decimal, in the circuit of Figure 47 should cause the output
voltage to be 16 × VIN. However, if the DAC has a linearity
specification of ±0.5 LSB, then D can in fact have the weight
anywhere in the range 15.5/256 to 16.5/256 so that the possible
output voltage will be in the range 15.5 VIN to 16.5 VIN—an error of
+3% even though the DAC itself has a maximum error of 0.2%.
DAC leakage current is also a potential error source in divider
circuits. The leakage current must be counterbalanced by an
opposite current supplied from the op amp through the DAC.
Since only a fraction D of the current into the VREF terminal is
routed to the IOUT1 terminal, the output voltage has to change
as follows:
Output Error Voltage due to DAC Leakage = (Leakage × R)/D
where R is the DAC resistance at the VREF terminal. For a DAC
leakage current of 10 nA, R = 10 k, and a gain (that is, 1/D) of 16,
the error voltage is 1.6 mV.
GND
IOUT1
IOUT2
RFB
VREF
VDD
ADDITIONAL PINS OMITTED FOR CLARITY.
VOUT
VIN
03162-048
Figure 47. Current Steering DAC as a Divider or Programmable Gain Element
REFERENCE SELECTION
When selecting a reference for use with the AD5426 series of
current output DACs, pay attention to the references output
voltage temperature coefficient specification. This parameter not
only affects the full-scale error, but can also affect the linearity (INL
and DNL) performance. The reference temperature coefficient
should be consistent with the system accuracy specifications. For
example, an 8-bit system required to hold its overall specification to
within 1 LSB over the temperature range 0°C to 50°C dictates
that the maximum system drift with temperature should be less
than 78 ppm/°C. A 12-bit system with the same temperature
range to overall specification within 2 LSBs requires a maximum
drift of 10 ppm/°C. By choosing a precision reference with low
output temperature coefficient this error source can be minimized.
Table 7 suggests some references available from Analog Devices
that are suitable for use with this range of current output DACs.
AMPLIFIER SELECTION
The primary requirement for the current-steering mode is an
amplifier with low input bias currents and low input offset
voltage. The input offset voltage of an op amp is multiplied by
the variable gain (due to the code-dependent output resistance
of the DAC) of the circuit. A change in this noise gain between
two adjacent digital fractions produces a step change in the
output voltage due to the amplifier’s input offset voltage. This
output voltage change is superimposed on the desired change in
output between the two codes and gives rise to a differential
linearity error, which, if large enough, could cause the DAC to
be nonmonotonic. In general, the input offset voltage should be
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相关代理商/技术参数 |
参数描述 |
|---|---|
| AD5443YRM-REEL | 制造商:Analog Devices 功能描述:DAC 1-CH R-2R 12-bit 10-Pin MSOP T/R 制造商:Analog Devices 功能描述:DAC 1CH R-2R 12-BIT 10MSOP - Tape and Reel 制造商:Rochester Electronics LLC 功能描述:12-BIT IOUT DAC WITH SERIAL ITF I.C. - Tape and Reel |
| AD5443YRM-REEL7 | 制造商:Analog Devices 功能描述:DAC 1-CH R-2R 12-bit 10-Pin MSOP T/R 制造商:Analog Devices 功能描述:DAC 1CH R-2R 12-BIT 10MSOP - Tape and Reel |
| AD5443YRMZ | 功能描述:IC DAC 12BIT SERIAL IOUT 10-MSOP RoHS:是 类别:集成电路 (IC) >> 数据采集 - 数模转换器 系列:- 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:50 系列:- 设置时间:4µs 位数:12 数据接口:串行 转换器数目:2 电压电源:单电源 功率耗散（最大）:- 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:8-TSSOP，8-MSOP（0.118"，3.00mm 宽） 供应商设备封装:8-uMAX 包装:管件 输出数目和类型:2 电压，单极 采样率（每秒）:* 产品目录页面:1398 (CN2011-ZH PDF) |
| AD5443YRMZ | 制造商:Analog Devices 功能描述:IC 12BIT DAC SERIAL I/F SMD 5443 |
| AD5443YRMZ-REEL | 功能描述:IC DAC 12BIT SERIAL IN 10MSOP RoHS:是 类别:集成电路 (IC) >> 数据采集 - 数模转换器 系列:- 产品培训模块:LTC263x 12-, 10-, and 8-Bit VOUT DAC Family 特色产品:LTC2636 - Octal 12-/10-/8-Bit SPI VOUT DACs with 10ppm/°C Reference 标准包装:91 系列:- 设置时间:4µs 位数:10 数据接口:MICROWIRE?，串行，SPI? 转换器数目:8 电压电源:单电源 功率耗散（最大）:2.7mW 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:14-WFDFN 裸露焊盘 供应商设备封装:14-DFN-EP（4x3） 包装:管件 输出数目和类型:8 电压，单极 采样率（每秒）:* |
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