SLYY234 December   2024 AMC0106M05 , AMC0106M25 , AMC0136 , AMC0311D , AMC0311S , AMC0386 , AMC0386-Q1 , AMC1100 , AMC1106M05 , AMC1200 , AMC1200-Q1 , AMC1202 , AMC1203 , AMC1204 , AMC1211-Q1 , AMC1300 , AMC1300B-Q1 , AMC1301 , AMC1301-Q1 , AMC1302-Q1 , AMC1303M2510 , AMC1304L25 , AMC1304M25 , AMC1305M25 , AMC1305M25-Q1 , AMC1306M05 , AMC1306M25 , AMC1311 , AMC1311-Q1 , AMC131M03 , AMC1336 , AMC1336-Q1 , AMC1350 , AMC1350-Q1 , AMC23C12 , AMC3301 , AMC3330 , AMC3330-Q1

 

  1.   1
  2.   Introduction
  3.   Introduction to Isolated Signal Chain
    1.     Comparing Isolated Amplifiers and Isolated Modulators
      1.      Abstract
      2.      Introduction to Isolated Amplifiers
      3.      Introduction to Isolated Modulators
      4.      Performance Comparison Between Isolated Amplifiers and Isolated Modulators
      5.      Isolated Modulators in Traction Inverters
      6.      Isolated Amplifier and Modulator Recommendations
      7.      Conclusion
    2.     TI’s First Isolated Amplifiers With Ultra-Wide Creepage and Clearance
      1.      Application Brief
  4.   Selection Trees
  5.   Current Sensing
    1.     Shunt Resistor Selection for Isolated Data Converters
      1.      17
    2.     Design considerations for isolated current sensing
      1.      19
      2.      Conclusion
      3.      References
      4.      Related Websites
    3.     Isolated Current-Sensing Circuit With ±50-mV Input and Single-Ended Output
      1.      24
    4.     Isolated Current-Sensing Circuit With ±50-mV Input and Differential Output
      1.      26
    5.     Isolated Current-Sensing Circuit With ±250-mV Input Range and Single-Ended Output Voltage
      1.      Design Goals
      2.      Design Description
      3.      Design Notes
      4.      Design Steps
      5.      Design Simulations
      6.      DC Simulation Results
      7.      Closed-Loop AC Simulation Results
      8.      Transient Simulation Results
      9.      Design References
      10.      Design Featured Isolated Amplifier
      11.      Design Alternate Isolated Amplifier
    6.     Isolated current-measurement circuit with ±250-mV input and differential output
      1.      Design Goals
      2.      Design Description
      3.      Design Notes
      4.      Design Steps
      5.      Design Simulations
      6.      DC Simulation Results
      7.      Closed Loop AC Simulation Results
      8.      Transient Simulation Results
      9.      Design References
      10.      Design Featured Op Amp
      11.      Design Alternate Op Amp
    7.     Isolated Overcurrent Protection Circuit
      1.      52
    8.     Interfacing a Differential-Output (Isolated) Amp to a Single-Ended Input ADC
      1.      54
    9.     Utilizing AMC3311 to Power AMC23C11 for Isolated Sensing and Fault Detection
      1.      Application Brief
    10.     Isolated Current-Sensing Circuit With Front-End Gain Stage
      1.      58
    11.     Accuracy Comparison of Isolated Shunt and Closed-Loop Current Sensing
      1.      60
  6.   Voltage Sensing
    1.     Maximizing Power Conversion and Motor Control Efficiency With Isolated Voltage Sensing
      1.      63
      2.      Solutions for high-voltage sensing
      3.      Integrated resistor devices
      4.      Single-ended output devices
      5.      Integrated isolated voltage-sensing use cases
      6.      Conclusion
      7.      Additional resources
    2.     Increased Accuracy and Performance with Integrated High Voltage Resistor Isolated Amplifiers and Modulators
      1.      Abstract
      2.      Introduction
      3.      High Voltage Resistor Isolated Amplifiers and Modulators Advantages
        1.       Space Savings
        2.       Improved Temperature and Lifetime Drift of Integrated HV Resistors
        3.       Accuracy Results
        4.       Fully Integrated Resistors vs. Additional External Resistor Example
        5.       Device Selection Tree and AC/DC Common Use Cases
      4.      Summary
      5.      References
    3.     Isolated Amplifiers With Differential, Single-Ended Fixed Gain and Ratiometric Outputs for Voltage Sensing Applications
      1.      Abstract
      2.      Introduction
      3.      Overview of Differential, Single-Ended Fixed Gain and Ratiometric Outputs
        1.       Isolated Amplifiers with Differential Output
        2.       Isolated Amplifiers With Single-Ended, Fixed-Gain Output
        3.       Isolated Amplifiers With Single-Ended, Ratiometric Output
      4.      Application Examples
        1.       Product Selection Tree
      5.      Summary
      6.      References
    4.     Isolated Voltage-Measurement Circuit With ±250-mV Input and Differential Output
      1.      93
    5.     Split-Tap Connection for Line-to-Line Isolated Voltage Measurement Using AMC3330
      1.      95
    6.     ±12V Voltage Sensing Circuit With an Isolated Amplifier and Pseudo-Differential Input SAR ADC
      1.      97
    7.     ±12-V voltage sensing circuit with an isolated amplifier and differential input SAR ADC
      1.      99
    8.     Isolated Undervoltage and Overvoltage Detection Circuit
      1.      101
    9.     Isolated Zero-Cross Detection Circuit
      1.      103
    10.     ±480V Isolated Voltage-Sensing Circuit With Differential Output
      1.      105
  7.   EMI Performance
    1.     Best in Class Radiated Emissions EMI Performance with Isolated Amplifiers
      1.      Best in Class Radiated Emissions EMI Performance with Isolated Amplifiers
      2.      Introduction
      3.      Current Generation of Texas Instruments Isolated Amplifiers Radiated Emissions Performance
      4.      Previous Generations of Texas Instruments Isolated Amplifiers Radiated Emissions Performance
      5.      Conclusion
      6.      References
    2.     Best Practices to Attenuate AMC3301 Family Radiated Emissions EMI
      1.      Abstract
      2.      Introduction
      3.      Effects of Input Connections on AMC3301 Family Radiated Emissions
      4.      Attenuating AMC3301 Family Radiated Emissions
        1.       Ferrite Beads and Common Mode Chokes
        2.       PCB Schematics and Layout Best Practices for AMC3301 Family
      5.      Using Multiple AMC3301 Devices
        1.       Device Orientation
        2.       PCB Layout Best Practices for Multiple AMC3301
      6.      Conclusion
      7.      AMC3301 Family Table
  8.   End Equipment
    1.     Comparing Shunt- and Hall-Based Isolated Current-Sensing Solutions in HEV/EV
      1.      128
    2.     Design Considerations for Current Sensing in DC EV Charging Applications
      1.      Abstract
      2.      Introduction
        1.       DC Charging Station for Electric Vehicles
        2.       Current-Sensing Technology Selection and Equivalent Model
          1.        Sensing of the Current With Shunt-Based Solution
          2.        Equivalent Model of the Sensing Technology
      3.      Current Sensing in AC/DC Converters
        1.       Basic Hardware and Control Description of AC/DC
          1.        AC Current Control Loops
          2.        DC Voltage Control Loop
        2.       Point A and B – AC/DC AC Phase-Current Sensing
          1.        Impact of Bandwidth
            1.         Steady State Analysis: Fundamental and Zero Crossing Currents
            2.         Transient Analysis: Step Power and Voltage Sag Response
          2.        Impact of Latency
            1.         Fault Analysis: Grid Short-Circuit
          3.        Impact of Gain Error
            1.         Power Disturbance in AC/DC Caused by Gain Error
            2.         AC/DC Response to Power Disturbance Caused by Gain Error
          4.        Impact of Offset
        3.       Point C and D – AC/DC DC Link Current Sensing
          1.        Impact of Bandwidth on Feedforward Performance
          2.        Impact of Latency on Power Switch Protection
          3.        Impact of Gain Error on Power Measurement
            1.         Transient Analysis: Feedforward in Point D
          4.        Impact of Offset
        4.       Summary of Positives and Negatives at Point A, B, C1/2 and D1/2 and Product Suggestions
      4.      Current Sensing in DC/DC Converters
        1.       Basic Operation Principle of Isolated DC/DC Converter With Phase-Shift Control
        2.       Point E, F - DC/DC Current Sensing
          1.        Impact of Bandwidth
          2.        Impact of Gain Error
          3.        Impact of Offset Error
        3.       Point G - DC/DC Tank Current Sensing
        4.       Summary of Sensing Points E, F, and G and Product Suggestions
      5.      Conclusion
      6.      References
    3.     Using isolated comparators for fault detection in electric motor drives
      1.      Introduction
      2.      Introduction to electric motor drives
      3.      Understanding fault events in electric motor drives
      4.      Achieving reliable detection and protection in electric motor drives
      5.      Use case No. 1: Bidirectional in-phase overcurrent detection
      6.      Use case No. 2: DC+ overcurrent detection
      7.      Use case No. 3: DC– overcurrent or short-circuit detection
      8.      Use case No. 4: DC-link (DC+ to DC–) overvoltage and undervoltage detection
      9.      Use case No. 5: IGBT module overtemperature detection
    4.     Discrete DESAT for Opto-Compatible Isolated Gate Driver UCC23513 in Motor Drives
      1.      Abstract
      2.      Introduction
      3.      System Challenge on Isolated Gate Drivers With Integrated DESAT
      4.      System Approach With UCC23513 and AMC23C11
        1.       System Overview and Key Specification
        2.       Schematic Design
          1.        Circuit Schematic
          2.        Configure VCE(DESAT) Threshold and DESAT Bias Current
          3.        DESAT Blanking Time
          4.        DESAT Deglitch Filter
        3.       Reference PCB Layout
      5.      Simulation and Test Results
        1.       Simulation Circuit and Results
          1.        Simulation Circuit
          2.        Simulation Results
        2.       Test Results With 3-Phase IGBT Inverter
          1.        Brake IGBT Test
          2.        Test Results on a 3-Phase Inverter With Phase to Phase Short
      6.      Summary
      7.      References
    5.     Isolated voltage sensing in AC motor drives
      1.      Introduction
      2.      Conclusion
      3.      References
    6.     Achieving High-Performance Isolated Current and Voltage Sensing in Server PSUs
      1.      Application Brief
  9.   Additional Reference Designs/Circuits
    1.     Designing a Bootstrap Charge-Pump Power Supply for an Isolated Amplifier
      1.      Abstract
      2.      Introduction
      3.      Bootstrap Power Supply Design
        1.       Selection of Charge Pump Capacitor
        2.       Simulation in TINA-TI
        3.       Hardware Test with AMC1311-Q1
      4.      Summary
      5.      Reference
    2.     Clock Edge Delay Compensation With Isolated Modulators Digital Interface to MCUs
      1.      Abstract
      2.      Introduction
      3.      Design Challenge With Digital Interface Timing Specifications
      4.      Design Approach With Clock Edge Delay Compensation
        1.       Clock Signal Compensation With Software Configurable Phase Delay
        2.       Clock Signal Compensation With Hardware Configurable Phase Delay
        3.       Clock Signal Compensation by Clock Return
        4.       Clock Signal Compensation by Clock Inversion at the MCU
      5.      Test and Validation
        1.       Test Equipment and Software
        2.       Testing of Clock Signal Compensation With Software Configurable Phase Delay
          1.        Test Setup
          2.        Test Measurement Results
        3.       Testing of Clock Signal Compensation by Clock Inversion at MCU
          1.        Test Setup
          2.        Test Measurement Results
            1.         Test Result – No Clock Inversion of Clock Input at GPIO123
            2.         Test Result – Clock Inversion of Clock Input at GPIO123
        4.       Digital Interface Timing Validation by Calculation Tool
          1.        Digital Interface With No Compensation Method
          2.        Commonly Used Method - Reduction of the Clock Frequency
          3.        Clock Edge Compensation With Software Configurable Phase Delay
      6.      Conclusion
      7.      References
    3.     Utilizing AMC3311 to Power AMC23C11 for Isolated Sensing and Fault Detection
      1.      Application Brief
Impact of Offset

Figure 75 shows the equivalent model of a real current sensor with offset. In this study, the current-sensor offset is modeled as a fixed-value normalized to the full scale of the measurement, see Equation 47.

Equation 47. IO=IMAX δO

where

  • I0 is the absolute offset value presented by the sensor
  • IMAX is the maximum of the measurement scale
  • ẟ0 is the per-unit value of the offset error introduced in the measurement

The goal of the current control loops of the AC/DC stage is to keep the currents detected by the MCU under control without determining the real currents in the system. If the measurement does not match the actual current due to an offset error, the current causes an undesired power disturbance in the system as is expressed with Equation 48.

Equation 48. ΔPO=V[IO1sin(ωt)+IO2sin(ωt-23π)+IO3sin(ωt+23π)]

where

  • ΔPO is the power disturbance caused by the offset errors as function of time
  • IO1, IO2, and IO3 are offset errors of each current sensor
  • V is the phase to neutral RMS voltage
  • ɷ is the electrical pulsation derived from the grid frequency

The power disturbance is not a function of the power conversion between the AC and DC stage, as opposed to the gain error case; therefore, the issue is always present for any operating condition. This reflects by always having voltage ripple in the DC link. The offset introduces a power disturbance in the system with a frequency equivalent to the line frequency of the grid. As mentioned in the gain error chapter, the DC bus voltage loop is not able to fully reject the power ripple coming out from the sensing point. For this reason control loop versus current-sensing performance must be simulated. Simulations were run for the following use-case and assumptions:

  • DC bus voltage working at the minimum rated voltage to maximize the ripple voltage (650 V)
  • Maximum power exchange between AC and DC side. This has no effect on the result. The results are the same for the no-load condition.
  • Offset error defined with respect to the full measurement scale per unit. When using a shunt-based design with ±50-mV isolated device, the maximum scale is ±32 A.
  • Offset for the three-phases applied to reach the worst-case scenario as follows: IO1 = –IO2 = –IO3
  • Current control-loop bandwidth kept constant in all the simulations (3 kHz)
  • AC filter designed with the aim to keep the grid THD at the nominal power at 3% when using ideal sensing
  • Power line frequency is 50 Hz

Figure 91 shows the simulation results of a AC/DC converter working with different current sensing and with different offset errors.

DC-Link Voltage Ripple Over Time With DC Link Bandwidth and Offset Error as ParametersFigure 91 DC-Link Voltage Ripple Over Time With DC Link Bandwidth and Offset Error as Parameters

Observe the presence of a 50-Hz ripple voltage on the DC-link, caused by the power ripple injected by the current sensing stage with an offset. Additionally, the mean value of the voltage in all the cases is still the same when steady state is reached thanks to the integrative part of the PI controller.

The important correlation between the DC link voltage ripple and voltage control bandwidth is evident. If the bandwidth of the voltage control loop is high enough, the control loop tries to eliminate the ripple voltage by quickly controlling the current loops at the expense of the THD toward the grid. In fact, with a bandwidth of the control equal to 400 Hz, an offset of 1.4% offset error, leads to an increment of 10% of the THD (from 3% to 3.3%). Conversely, when the bandwidth of the voltage loop is not high, fluctuation in the DC link is very high because voltage loop is not trying to reject this variation, but this time not injecting any more harmonics in the grid. However, remember that having a voltage ripple in the DC-link can lead to power ripple on the battery which cannot be tolerated. Furthermore, if the voltage bandwidth is significantly reduced, the performance of the step load response becomes quite poor.

In conclusion, a current sensor located in the switching node with an offset error of 1.4% can lead to an increment of the grid current THD of more than 10%.