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[原创] TI DAC8775自适应功率管理四路DAC解决方案

关键词:工业控制 过程控制 PLC DAC8775

时间:2017-04-01 13:19:10       作者:TI       来源:中电网

摘要:TI公司的DAC8775是自适应功率管理四路16位可编程电流输出和电压输出的数模转换器(DAC),工作电压12 V – 36 V,DNL: ±1 LSB,工作温度–40°C 到 +125°C,主要用在4-mA-20-mA电流回路,模拟输出模块,可编程逻辑控制器(PLC),建筑物自动化,传感器发送器和过程控制.本文介绍了DAC8775主要特性,框图,以及评估模块DAC8775EVM主要特性,框图,电路图,材料清单和PCB元件布局图.

The DAC8775 is a quad-channel precision, fullyintegrated, 16-bit, digital-to-analog converter (DAC)with adaptive power management, and is designed tomeet the requirements of industrial controlapplications. The adaptive power managementcircuit, when enabled, minimizes the powerdissipation of the chip. When programmed as acurrent output, the supply voltage on the currentoutput driver is regulated between 4.5 V and 32 Vbased on continuous feedback of voltage on thecurrent output pin via an integrated buck/boostconverter. When programmed as a voltage output,this circuit generates a programmable supply voltagefor the voltage output stage (±15 V). DAC8775 alsocontains an LDO to generate the digital supply (5 V)from a single power supply pin.

DAC8775 is also implemented with a HighwayAddressable Remote Transducer (HART) SignalInterface to superimpose an external HART signal onthe current output. The slew rate of the current outputDAC is register programmable. The device canoperate with a single external power supply of +12 Vto +36 V using the integrated buck/boost converters

or with external power supplies when the buck/boostconverters are disabled.

DAC8775主要特性:

1• Output Current:

– 0 mA to 24 mA; 3.5 mA to 23.5 mA; 0 mA to20 mA; 4 mA to 20 mA; ±24 mA

• Output Voltage (with/without 20% over-range):

– 0 V to 5 V; 0 V to 10 V; ±5 V; ±10 V

– 0 V to 6 V; 0 V to 12 V; ±6 V; ±12 V

• Adaptive Power Management

• Single Wide Power Supply Pin (12 V – 36 V )

• ±0.1% FSR Total Unadjusted Error (TUE)

• DNL: ±1 LSB Max

• Internal 5-V Reference (10 ppm/°C max)

• Internal 5-V Digital Power Supply Output

• CRC/Frame Error Check, Watchdog Timer

• Thermal Alarm, Open/Short Circuit for SystemReliability

• Safe Actions on Alarm Condition

• Auto Learn Load Detection

• Wide Temperature Range: –40°C to +125°C

DAC8775应用:

• 4-mA to 20-mA Current Loops

• Analog Output Modules

• Programmable Logic Controllers (PLCs)

• Building Automation

• Sensor Transmitters

• Process Control

图1.DAC8775框图

图2.DAC8775在四路PLC AO模式连接图

评估模块DAC8775EVM

The DAC8775EVM (evaluation module) is an easy to use platform for evaluating the functionality and performance of the DAC8775 device. The DAC8775 is a Quad-Channel, 16-Bit Programmable Current or Voltage Output Digital-to-Analog Converter with Adaptive Power Management. The EVM is a complete evaluation kit that includes a PCB, SM-USB-DIG, USB Cable and evaluation software that is compatible with Microsoft Windows™ XP and Windows™ 7/8/10 operating systems.

图3.评估模块DAC8775EVM外形图

评估模块DAC8775EVM主要特性:

Quad-Channel,16-Bit Programmable Current Output and Voltage Output 

Adaptive Buck-Boost Power Management 

Single Wide Power Supply Range (12V-36V) 

Output Current Ranges: 0-24 mA; 3.5-23.5 mA; 0-20 mA; 4-20 mA; ±24 mA

Output Voltage Ranges: 0-5 V; 0-10 V; ±5 V; ±10 V (All are configurable with or without 20% over-range)

图4.评估模块DAC8775EVM框图

图5.评估模块DAC8775EVM电路图(1)

图6.评估模块DAC8775EVM电路图(2)

图7.评估模块DAC8775EVM电路图(3)

评估模块DAC8775EVM材料清单:

图8.评估模块DAC8775EVM PCB元件布局图

详情请见:

http://www.ti.com/lit/ds/symlink/dac8775.pdf

http://www.ti.com/lit/ug/sbau248/sbau248.pdf

dac8775.pdf

sbau248.pdf

 

 

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