AD4111低功耗低噪音24位Σ－ΔADC解決方案

ADI公司的AD4111是具有±10V和0 mA至20 mA輸入和明線檢測功能的低功耗 24 位 Σ-Δ ADC，集成了模擬前端（AFE），還集成主要模擬和數(shù)字的信號調(diào)理區(qū)快，為每個模擬輸入通路配置成八種單獨建立圖，最大通路掃描速率6.2 kSPS（161 μs），嵌入的2.5V低漂移（5 ppm/℃）能隙基準(zhǔn)電壓降低了外接元件數(shù)量，單電源5V或3.3V工作，工作溫度?40℃ 到 +105℃，主要用在過程控制PLC和DCS模塊。本文介紹了AD4111主要特性，功能框圖以及評估板EVAL-AD4111SDZ主要特性，框圖，電路圖，材料清單和PCB設(shè)計圖。

The AD4111 is a low power， low noise， 24-bit， sigma-delta （Σ-Δ） analog-to-digital converter （ADC） that integrates an analog front end （AFE） for fully differential or single-ended， high impedance（≥1 MΩ） bipolar，±10 V voltage inputs， and 0 mA to 20 mA current inputs. The AD4111 also integrates key analog and digital signalconditioning blocks to configure eight individual setups for each analog input channel in use. The AD4111 features amaximum channel scan rate of 6.2 kSPS （161 μs） for fullysettled data.

The embedded 2.5 V， low drift （5 ppm/℃）， band gap internal reference （with output reference buffer） reduces the external component count. The digital filter allows flexible settings， including simultaneous50 Hz and 60 Hz rejection at a 27.27 SPS output data rate. The user can select between the different filter settings depending on the demands of each channel in the application. The automatic channel sequencer enables the ADC to switch through eachenabled channel.

The precision performance of the AD4111 is achieved by integrating the proprietary iPassives? technology from Analog Devices， Inc. The AD4111 is factory calibrated to achieve a high degree of specified accuracy.

The AD4111 also has the unique feature of open wire detection on the voltage inputs （patent pending） for system level diagnosticsusing a single 5 V or 3.3 V power supply. The AD4111 operates with a single power supply， making it easy to use in galvanically isolated applications. The specified operating temperature range is ?40℃ to +105℃。 The AD4111 is housedin a 40-lead， 6 mm × 6 mm LFCSP package.

AD4111主要特性：

24-bit ADC with integrated analog front end

Up to 6.2 kSPS per channel （161 μs per channel）

16 noise free bits at 1 kSPS per channel

85 dB rejection of 50 Hz and 60 Hz at 20 SPS per channel

±10 V inputs， 4 differential or 8 single-ended Overrange up to ±20 V ≥1 MΩ impedance

±0.06% accuracy at 25℃ Open wire detection 0 mA to 20 mA inputs，4 single-ended Overrange from ?0.5 mA to +24 mA

60 Ω impedance

±0.08% accuracy at 25℃ On-chip 2.5 V reference ±0.12% accuracy at 25℃

， ±5 ppm/℃ （typical） drift Internal or external clock

Power supplies

AVDD = 3.0 V to 5.5 V

IOVDD = 2 V to 5.5 V

Total IDD = 3.9 mA

Temperature range： ?40℃ to +105℃ 3-wire or 4-wire serial digital interface （Schmitt trigger on SCLK）

SPI， QSPI， MICROWIRE， and DSP compatible

AD4111應(yīng)用：

Process control PLC and DCS modules

圖1.AD4111功能框圖

評估板EVAL-AD4111SDZ

Evaluating the AD4111 ±10 V and 0 mA to 20 mA， Analog Front End forIndustrial Automation Systems

The EVAL-AD4111SDZ evaluation kit features the AD4111，a 24-bit， 31.25 kSPS analog-to-digital converter （ADC） with a±10 V input voltage range （4 single-ended or 8 differentialchannels） with open wire detection and 4 current channelsoperating from 0 mA to 20 mA. All channels have on-board overvoltage and overcurrent protection. The EVAL-AD4111SDZ board includes voltage reference， power， and data insulation and can be connected to the Analog Devices， Inc.， SDP-B system demonstration platform （EVAL-

SDP-CB1Z）。 The SDP-B board provides connection to a PC viaUSB port and can provide power for the EVAL-AD4111SDZboard from the PC USB port.

The AD411X Eval+ evaluation software configures the AD4111device functionality and provides open wire detection， dc timedomain analysis in the form of waveform graphs， histograms，and associated noise analysis for ADC performance evaluation.

Full specifications for the AD4111 are available in the productdata sheet， which must be consulted in conjunction with thisuser guide when working with this evaluation board.

評估板EVAL-AD4111SDZ主要特性：

Fully featured evaluation board for the AD4111

PC control in conjunction with Analog Devices， Inc.， SDP-B

system demonstration platform （EVAL-SDP-CB1Z）

PC software for control and data analysis （time domain）

評估板EVAL-AD4111SDZ包括：

EVAL-AD4111SDZ evaluation board

Required software： AD411X Eval+

圖2.評估板EVAL-AD4111SDZ外形圖

圖3. 評估板EVAL-AD4111SDZ框圖

圖4. 評估板EVAL-AD4111SDZ硬件配置圖

圖5.評估板EVAL-AD4111SDZ電路圖：AD4111

圖6.評估板EVAL-AD4111SDZ電路圖：電壓輸入前端

圖7.評估板EVAL-AD4111SDZ電路圖：電流輸入前端

圖8.評估板EVAL-AD4111SDZ電路圖：SDP連接器

圖9.評估板EVAL-AD4111SDZ電路圖：隔離和電源

評估板EVAL-AD4111SDZ材料清單：

圖10.評估板EVAL-AD4111SDZ PCB設(shè)計圖：頂層

圖11.評估板EVAL-AD4111SDZ PCB設(shè)計圖：元件絲印（頂層）

圖12.評估板EVAL-AD4111SDZ PCB設(shè)計圖：元件邊（層1）

圖13.評估板EVAL-AD4111SDZ PCB設(shè)計圖：焊接邊（層2）

詳情請見：

和

AD4111.pdf

EVAL-AD4111SDZ-UG-1124.pdf