Isolated, High-Accuracy Analog Input Module Reference Design Using 16-Bit ADC and Digital Isolator

(ACTIVE) TIDA-01214

Description & Features

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Key Document

Description

This reference design provides accurate measurements of AC voltage and current inputs using a precision 16-bit SAR ADC over a wide input range, covering protection and measurement range (including sampling requirements of IEC 61850-9-2), simplifying system design and improving trip time performance and reliability. The analog input module (AIM) is isolated from the host processor using a digital isolator with an integrated power. For a limited function and cost optimized  design approach, An AC AIM can be designed using only three TI products, reducing system cost and board size. The alarm feature identifies the AC analog input faults on a sample basis for faster fault detection. The ADC has an additional auxiliary channel to diagnose the supply output of the digital isolator. A 12-bit ADS8668 ADC with a gain amplifier can increase the dynamic range by using programmable internal ranges, further optimizing the system cost.

Features
  • This reference design is based on ADS8688A 16-bit SAR ADC and supports measurement of up to 16 analog inputs by daisy chaining
  • ADC interface isolated from host for improved safety in harsh operating conditions using ISOW7841 with integrated power converter providing current output of > 60 mA with efficiency ≥ 45%
  • AC AIM provides ENOB of > 14.9 bits, SNR of > 91 dB, and THD of > –110 dB
  • 12-bit ADC8668 with front-end gain amplifier for increasing dynamic range of low-voltage output sensors in cost-optimized applications
  • Load switch used at input of ISOW7841 to protect AC AIM during output overload

View the Important Notice for TI Designs covering authorized use, intellectual property matters and disclaimers.


  




TI Devices (33)

Order samples, get tools and find more information on the TI products in this reference design.

Part Number Name Product Family Sample & Buy Design Kits & Evaluation Modules
ADS8668  12-bit SAR ADC, 8 channels, 500 kSPS, and bipolar inputs off +5V supply  Analog-to-Digital Converters (ADCs)  Sample & Buy View Design Kits & Evaluation Modules
ADS8678  14-bit SAR ADC, 8 channels, 500 kSPS, and bipolar inputs off +5V supply  Analog-to-Digital Converters (ADCs)  Sample & Buy View Design Kits & Evaluation Modules
ADS8688  16-Bit, 500-kSPS, 8-Channel, Single-Supply, SAR ADCs with Bipolar Input Ranges  Analog-to-Digital Converters (ADCs)  Sample & Buy View Design Kits & Evaluation Modules
ADS8688A  16-bit SAR ADC, 8 channels, 500 kSPS, and bipolar inputs off +5V supply  Analog-to-Digital Converters (ADCs)  Sample & Buy View Design Kits & Evaluation Modules
ADS8698  18-bit SAR ADC, 8 channels, 500 kSPS, and bipolar inputs off +5V supply  Analog-to-Digital Converters (ADCs)  Sample & Buy View Design Kits & Evaluation Modules
CSD17571Q2  30V N-Channel NexFET Power MOSFETs, CSD17571Q2  Power MOSFET  Sample & Buy View Design Kits & Evaluation Modules
INA333  Low-Power, Zero-Drift, Precision Instrumentation Amplifier  Amplifiers  Sample & Buy View Design Kits & Evaluation Modules
ISO7741  High-Speed, Low-Power, Robust EMC Quad-Channel Digital Isolator  Isolation  Sample & Buy View Design Kits & Evaluation Modules
ISO7841  High-Immunity, 5.7kVRMS Reinforced Quad-Channel 3/1 Digital Isolator, 100Mbps  Isolation  Sample & Buy View Design Kits & Evaluation Modules
ISOW7841  High-Efficiency, Low-Emissions, Reinforced Digital Isolator With Integrated Power  Isolation  Sample & Buy View Design Kits & Evaluation Modules
LM27762  Low-Noise Positive- and Negative-Output Charge Pump With Integrated LDO  Buck/Boost, Inverting or Split-Rail  Sample & Buy View Design Kits & Evaluation Modules
LM5001  3.1-75V Wide Vin, 1A Current Mode Non-Synchronous Switch Mode Regulator  Step-Up (Boost)  Sample & Buy View Design Kits & Evaluation Modules
LMT70  ±0.1°C Precision Analog Temperature Sensor  Temperature Sensors  Sample & Buy View Design Kits & Evaluation Modules
OPA320  Precision, Zero-Crossover, 20MHz, 0.9pA Ib, RRIO, CMOS Operational Amplifier  Operational Amplifiers (Op Amps)  Sample & Buy View Design Kits & Evaluation Modules
OPA322  20MHz Low-Noise 1.8V RRIO CMOS Operational Amplifier With Shutdown  Operational Amplifiers (Op Amps)  Sample & Buy View Design Kits & Evaluation Modules
OPA376  Precision, Low Noise, Low Iq Operational Amplifier  Operational Amplifiers (Op Amps)  Sample & Buy View Design Kits & Evaluation Modules
OPA4180  0.1 uV/C Drift, Quad, Low Noise, Rail-to-Rail, 36V Zero Drift Op Amp  Operational Amplifiers (Op Amps)  Sample & Buy View Design Kits & Evaluation Modules
REF5040  Low Noise, Very Low Drift, Precision Series Voltage Reference  Voltage Reference  Sample & Buy Not Available
REF6041  High-Precision Voltage Reference With Integrated High-Bandwidth Buffer  Voltage Reference  Sample & Buy View Design Kits & Evaluation Modules
REG71055  60-mA, 5.5V, Buck/boost Charge Pump in ThinSOT-23  Buck/Boost, Inverting or Split-Rail  Sample & Buy Not Available
SN6505B  Low-Noise 1-A , 420kHz Transformer Driver for Isolated Power Supplies  Isolation  Sample & Buy View Design Kits & Evaluation Modules
SN74LVC1G17  Single Schmitt-Trigger Buffer  Logic  Sample & Buy View Design Kits & Evaluation Modules
TLV3012  Nanopower, 1.8V, SOT23 Push-Pull Comparator with Voltage Reference  Amplifiers  Sample & Buy View Design Kits & Evaluation Modules
TPS22944  5.5V, 0.2A, 500mΩ, 100mA Current Limit Load Switch  Integrated Load Switches  Sample & Buy View Design Kits & Evaluation Modules
TPS3808  Low Quiescent Current, Programmable-Delay Supervisory Circuit  Power Management  Sample & Buy View Design Kits & Evaluation Modules
TPS3836  NanoPower Supervisory Circuits  Power Management  Sample & Buy View Design Kits & Evaluation Modules
TPS60241  170 uVrms Zero-Ripple Switched Cap Boost Converter With Fixed 5.0V Output For VCO Supply  Step-Up (Boost)  Sample & Buy View Design Kits & Evaluation Modules
TPS60403  60mA Charge Pump Voltage Inverter with Fixed 250kHz Operation  Buck/Boost, Inverting or Split-Rail  Sample & Buy View Design Kits & Evaluation Modules
TPS61040  28-V, 400-mA Switch Boost Converter in SOT-23 for LCD and White LED Applications  Step-Up (Boost)  Sample & Buy View Design Kits & Evaluation Modules
TPS717  150mA, High PSRR, Low Quiescent Current, Low Noise LDO  Linear Regulator (LDO)  Sample & Buy View Design Kits & Evaluation Modules
TPS723  200mA, Negative Output Low-Dropout Linear Regulator  Linear Regulator (LDO)  Sample & Buy Not Available
TPS791  Ultralow Noise, High PSRR, Fast RF 100-mA Low-Dropout Linear Regulators  Linear Regulator (LDO)  Sample & Buy View Design Kits & Evaluation Modules
TPS7A49  Vin 3V to 36V, 150mA, Ultra-Low Noise, High PSRR, Low-Dropout Linear Regulator  Linear Regulator (LDO)  Sample & Buy View Design Kits & Evaluation Modules

Technical Documents

View the Important Notice for TI Designs covering authorized use, intellectual property matters and disclaimers.

User guides (1)
Title Abstract Type Size (KB) Date Views TI Recommends
PDF 923 05 Sep 2017 391
Design files (6)
Title Abstract Type Size (KB) Date Views
ZIP 2975 05 Sep 2017 65
ZIP 7943 05 Sep 2017 131
ZIP 4008 05 Sep 2017 83
ZIP 716 05 Sep 2017 56
ZIP 520 05 Sep 2017 138
ZIP 1254 05 Sep 2017 431


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