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[原创] TI ISO2245 kVRMS增强隔离放大器解决方案

关键词:电源管理 隔离放大器 信号采集系统 ISO224

时间:2019-01-21 10:59:36       作者:TI       来源:中电网

TI公司的ISO224是增强隔离放大器,输入和输出采用隔离层进行隔离,电流隔离高达5 kVRMS,单端输入±12 V,差分输出±4V,具有极好长寿命和低功耗,工作温度–40℃到 +125℃,主要用在电网自动化,保护继电器,工厂自动化和控制,轨道交通,马达驱动以及功率分析器.本文介绍了ISO224主要特性,框图,应用电路以及评估模块ISO224EVM主要特性,电路图,材料清单和PCB丝印图.

The ISO224 is a precision isolated amplifier with anoutput separated from the input circuitry by anisolation barrier with high immunity to magneticinterference. This barrier is certified to providereinforced galvanic isolation of up to 5 kVRMS with anexceptionally long lifetime and low power dissipation.

When used with isolated power supplies, this deviceseparates parts of the system that operate ondifferent common-mode voltage levels and protectslower-voltage devices from damage.

The input of the ISO224 is optimized for accuratesensing of ±10-V signals that are widely used inindustrial applications. The device operates of asingle supply on the high-side. This unique featuresimplifies the design of the isolated power supply andreduces the system cost. The integrated high-sidesupply voltage detection feature simplifies system level diagnostics. The ±4-V output of the ISO224allows lower-cost analog-to-digital converters (ADCs)to be used. The differential structure of the outputsupports high immunity to noise.

The ISO224 is fully specified over the extendedindustrial temperature range of –40℃ to +125℃ andis available in a wide-body 8-pin SOIC (DWV)package.

ISO224主要特性:

• Offered in High-Grade (ISO224B) and Low-Grade(ISO224A) Versions
• ±12-V Input Voltage Range Optimized for IsolatedVoltage Measurement in Industrial Applications
• Overvoltage Input Clamp With 9-kV ESD
• ±4-V Differential Output Voltage Range WithCommon-Mode at VDD2/2
• Low DC-Error Operation (ISO224B):
– Input Offset: ±5 mV at 25℃, ±42 μV/¡ãC max
– Gain Error: ±0.3% at 25℃, ±50 ppm/℃ max
– Nonlinearity: ±0.01% max, ±1 ppm/℃
• 4.5-V to 18-V Single-Supply on High-Side
• 4.5-V to 5.5-V Operation on Low-Side
• Safety-Related Certifications:
– 7071-VPEAK Reinforced Isolation per DIN VDEV 0884-11: 2017-01
– 5000-VRMS Isolation for 1 Minute per UL1577
• High CMTI: 140 kV/μs (typ),75 kV/μs (min)

ISO224应用:

• Isolated Signal Acquisition in:
– Grid Automation
– Protection Relays
– Factory Automation and Control
– Rail Transport
– Motor Drives
– Power Analyzers

图1.ISO224框图

图2.ISO224简化电路图

图3.ISO224用于AC电压检测电路图

图4.基于SN6501的高边电源电路

评估模块ISO224EVM

This user’s guide describes the characteristics, operation, and use of the ISO224EVM. This evaluationmodule (EVM) is an evaluation and development kit for evaluating the ISO224 precision isolation amplifier.

A complete circuit description as well as schematic diagram and bill of materials are included.

The ISO224 is a precision isolation amplifier with an output separated from the input circuitry by a silicondioxide (SiO2) barrier that is highly resistant to magnetic interference. This barrier has been certified toprovide basic galvanic isolation of up to 7000 VPEAK according to UL1577 and IEC60747-5-2 specifications.

The input of the ISO224 is optimized for accurate sensing of ±10 V signals that are widely used inindustrial applications. The ISO224 operates on a single 5 V power supply on the high-side whichdramatically simplifies the design of the isolated power supply which reduces overall system costs.

Throughout this document, the abbreviation EVM and the term evaluation module are synonymous withthe ISO224EVM.

评估模块ISO224EVM主要特性:

• Full-featured evaluation board for the ISO224 single-channel precision isolation amplifier
• Screw terminals for easy access to analog inputs and outputs
• Transformer and rectifiers to provide isolated power to VDD1 from VDD2
• Differential to Single-ended output options


图5.评估模块ISO224EVM外形图

ISO224EVM ISO224 Reinforced Isolated Amplifier With Single-Ended ±12V Input and ±4V Differential Output Evaluation Board Image

图6.评估模块ISO224EVM电路图
评估模块ISO224EVM材料清单:


图7.评估模块ISO224EVM PCB丝印图
详情请见:
http://www.ti.com/lit/ds/symlink/iso224.pdf
http://www.ti.com/lit/ug/slau733/slau733.pdf
iso224.pdf
slau733.pdf

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