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

Design Goals

High

Side Supply

Input

Voltage

Working Voltage

Low Side Supply

Output Voltage

12 V

±170 Vpk Sine Wave

≥ 400 VRMS

3.3 V to 5.0 V ±10%

≤ Low-Side Supply

Design Description

A zero-crossing detector circuit changes output state when the AC input crosses the zero-cross reference voltage. This design features a single chip solution for zero-crossing detection of an AC sine wave with inverting and non-inverting digital outputs. The circuit is created by setting the comparator inverting input to ground and applying a clamped sine wave to the noninverting input. The input voltage is clamped by R1 and a pair of antiparallel diodes. In this case, diodes are used instead of an attenuator to maximize the slew rate of the input near the zero-crossing, which reduces output latency. The circuit is used for AC line zero-cross detection in control circuits to reduce standby and off-mode power consumption.

Isolated Zero-Cross Detection Circuit Schematic Isolated Zero-Cross Detection Circuit Schematic

Design Notes

  1. The circuit must be capable of handling 750-V working voltage across the isolation barrier.
  2. The maximum input voltage at IN+ must be ±1 V
  3. Inverting and non-inverting output are desired
  4. Maximum current flowing through R1 is 100 µA ±10%
  5. Limit the operating voltage of each resistor in the string to 100 V ±10% maximum
  6. The input AC source voltage is 120 VRMS, higher AC voltages are easily accommodated with component modifications. See the Alternate Design section for details
  7. Ensure the hysteresis voltage at the AC zero-cross is no more than ±30 mV

Design Steps

  1. Determine the ideal R1 resistor value. The maximum peak input voltage of 120 VRMS × √2 = 170 VPK. Note that the forward voltage of the diode D1 is near zero, and not included in this calculation.
    R 1 = 170   V P K 100   µ A = 1 . 70   M Ω
  2. Divide R1 into 3 equal resistors to maintain design limits of ≤ 100 V per resistor:
    R 1 = 1 . 70   M Ω 3 = 566 . 66   k Ω
  3. Use the Analog Engineer’s Calculator to find a standard E96 1% resistor value for R1. The nearest value is 569 kΩ.
  4. Select the anti-parallel diodes. Choose diodes which will provide at least ± 350-mV forward voltage with the 100 µA supplied through R1.
  5. Optional – design low-pass filter at VINP defined by R2 and C1. The frequency response is defined as:
    F C = 1 2 π × R 2 × C 1

Revised Design

The following schematic shows implementation of the revised design using the AMC23C10.

Revised Design With AMC23C10 Isolated Comparator Revised Design With AMC23C10 Isolated Comparator

The AMC23C10 uses capacitive isolation to provide a working voltage of 1000 V. The voltage source for VDD1 is specified from 3 V to 27 V, controlled internally through an LDO. VDD2 is specified from 2.7 V to 5.5 V. The input voltage range under normal operation is ±1 V. The logic output on OUT1 is open drain which can be used with a pullup resistor to VDD1. OUT2 is a push-pull type output needing no external pullup resistors.

Design Simulations

Simulation of Zero-Crossing Detection With Sine Wave Input Simulation of Zero-Crossing Detection With Sine Wave Input
Simulation of Zero-Crossing Detection With Rectified Input Simulation of Zero-Crossing Detection With Rectified Input
Simulation of Response Time for Zero-Crossing Detection Simulation of Response Time for Zero-Crossing Detection

Measured Response

The following images show the measured response of the zero-crossing detection circuit using the AMC23C10 isolated comparator. The input is captured on trace 1, while OUT1 and OUT2 are shown on traces 2 and 3 respectively. When measured at both the rising and falling edges of the input, the delay between the zero-crossing of the input and the output transition does not exceed 220 ns.

Zero-Crossing Detection of Rectified Input Zero-Crossing Detection of Rectified Input
Zero-Crossing Detection Output Latency – Falling Edge Zero-Crossing Detection Output Latency – Falling Edge
Zero-Crossing Detection Output Latency – Rising Edge Zero-Crossing Detection Output Latency – Rising Edge

Design References

See Analog Engineer's Circuit Cookbooks for TI's comprehensive circuit library.

Texas Instruments, AMC23C10 Fast Response, Reinforced Isolated Comparator With Dual Output data sheet

Design Featured Isolated Comparator

AMC23C10
Working Voltage 1000 VRMS
VDD1 3.0 V–27 V
VDD2 2.7 V–5.5 V
Input Voltage Range ±1000 mV
Output Options OUT1 - Open Drain
OUT2 - Push-Pull
AMC23C10

Alternate Design for 230-VAC Input

AMC23C10
Working Voltage 1000 VRMS
AC Input 325 Vpk
R1 Ideal 3.25 MΩ
R1 E96 Standard Three each 1.09 MΩ