- 您现在的位置：买卖IC网 > PDF目录17065 > EVAL-AD5452EBZ (Analog Devices Inc)BOARD EVAL FOR AD5452 PDF资料下载
参数资料
| 型号： | EVAL-AD5452EBZ |
| 厂商： | Analog Devices Inc |
| 文件页数： | 10/28页 |
| 文件大小： | 0K |
| 描述： | BOARD EVAL FOR AD5452 |
| 标准包装： | 1 |
| 系列： | * |
第1页第2页第3页第4页第5页第6页第7页第8页第9页当前第10页第11页第12页第13页第14页第15页第16页第17页第18页第19页第20页第21页第22页第23页第24页第25页第26页第27页第28页
AD5450/AD5451/AD5452/AD5453
Data Sheet
Rev. G | Page 18 of 28
Stability
In the I-to-V configuration, the IOUT of the DAC and the
inverting node of the op amp must be connected as close as
possible, and proper PCB layout techniques must be employed.
Because every code change corresponds to a step function, gain
peaking may occur if the op amp has limited gain bandwidth
product (GBP) and there is excessive parasitic capacitance at the
inverting node. This parasitic capacitance introduces a pole into
the open-loop response, which can cause ringing or instability
in the closed-loop applications circuit.
An optional compensation capacitor, C1, can be added in parallel
small a value of C1 can produce ringing at the output, and too
large a value can adversely affect the settling time. C1 should be
found empirically, but 1 pF to 2 pF is generally adequate for the
compensation.
SINGLE-SUPPLY APPLICATIONS
Voltage-Switching Mode
Figure 46 shows these DACs operating in the voltage-switching
mode. The reference voltage, VIN, is applied to the IOUT1 pin, and
the output voltage is available at the VREF terminal. In this
configuration, a positive reference voltage results in a positive
output voltage, making single-supply operation possible. The
output from the DAC is voltage at a constant impedance (the
DAC ladder resistance); therefore, an op amp is necessary to
buffer the output voltage. The reference input no longer sees
constant input impedance, but one that varies with code;
therefore, the voltage input should be driven from a low
impedance source.
04587-011
NOTES
1. ADDITIONAL PINS OMITTED FOR CLARITY.
2. C1 PHASE COMPENSATION (1pF TO 2pF) MAY BE REQUIRED
IF A1 IS A HIGH SPEED AMPLIFIER.
RFB
VIN
IOUT1
VREF
GND
VDD
VOUT
R1
R2
Figure 46. Single-Supply Voltage-Switching Mode
It is important to note that with this configuration VIN is limited
to low voltages because the switches in the DAC ladder do not
have the same source-drain drive voltage. As a result, their on
resistance differs, which degrades the integral linearity of the
DAC. Also, VIN must not go negative by more than 0.3 V, or an
internal diode turns on, causing the device to exceed the
maximum ratings. In this type of application, the full range of
multiplying capability of the DAC is lost.
Positive Output Voltage
The output voltage polarity is opposite to the VREF polarity for
dc reference voltages. To achieve a positive voltage output, an
applied negative reference to the input of the DAC is preferred
over the output inversion through an inverting amplifier
because of the resistors’ tolerance errors. To generate a negative
reference, the reference can be level-shifted by an op amp such
that the VOUT and GND pins of the reference become the virtual
ground and 2.5 V, respectively, as shown in Figure 47.
04587-012
NOTES
1. ADDITIONAL PINS OMITTED FOR CLARITY.
2. C1 PHASE COMPENSATION (1pF TO 2pF) MAY BE REQUIRED
IF A1 IS A HIGH SPEED AMPLIFIER.
RFB
IOUT1
GND
–5V
+5V
ADR03
GND
VOUT
VIN
VREF
–2.5V
VDD
VDD = +5V
C1
VOUT = 0V TO +2.5V
Figure 47. Positive Output Voltage with Minimum Components
ADDING GAIN
In applications in which 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 the temperature coefficients of the
DAC’s thin film resistors. Simply placing a resistor in series
with the RFB resistor causes mismatches in the temperature
coefficients and results in larger gain temperature coefficient
errors. Instead, increase the gain of the circuit by using the
recommended configuration shown in Figure 48. R1, R2, and
R3 should have similar temperature coefficients, but they need
not match the temperature coefficients of the DAC. This
approach is recommended in circuits where gains greater than 1
are required.
04587-013
NOTES
1. ADDITIONAL PINS OMITTED FOR CLARITY.
2. C1 PHASE COMPENSATION (1pF TO 2pF) MAY BE REQUIRED
IF A1 IS A HIGH SPEED AMPLIFIER.
RFB
IOUT1
GND
R1
VREF
VIN
VDD
C1
VOUT
R3
R2
GAIN =
R2 + R3
R2
R1 =
R2R3
R2 + R3
Figure 48. Increasing Gain of Current-Output DAC
相关PDF资料 |
PDF描述 |
|---|---|
| EBA22DRMH | CONN EDGECARD 44POS .125 SQ WW |
| ACM03DRXN | CONN EDGECARD 6POS DIP .156 SLD |
| ESA06DTKT-S288 | CONN EDGECARD 12POS .125 EXTEND |
| RSM08DRUI | CONN EDGECARD 16POS DIP .156 SLD |
| UPB2G121MRD | CAP ALUM 120UF 400V 20% RADIAL |
相关代理商/技术参数 |
参数描述 |
|---|---|
| EVAL-AD5453EBZ | 功能描述:BOARD EVALUATION FOR AD5453 RoHS:是 类别:编程器，开发系统 >> 评估板 - 数模转换器 (DAC) 系列:- 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 |
| EVAL-AD5453SDZ | 功能描述:BOARD EVAL FOR AD5453 RoHS:是 类别:编程器，开发系统 >> 评估板 - 数模转换器 (DAC) 系列:- 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 |
| EVAL-AD5501EBZ | 功能描述:BOARD EVAL FOR AD5501 RoHS:是 类别:编程器，开发系统 >> 评估板 - 数模转换器 (DAC) 系列:- 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 |
| EVAL-AD5504EBZ | 功能描述:BOARD EVAL FOR AD5504 RoHS:是 类别:编程器，开发系统 >> 评估板 - 数模转换器 (DAC) 系列:nanoDAC™ 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 |
| EVAL-AD5516-1EB | 制造商:Analog Devices 功能描述:EVALUATION BOARD I.C. - Bulk |
发布紧急采购，3分钟左右您将得到回复。