SLUAB06 January   2025 AMC131M02 , AMC3330 , ISO7731

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2Topologies for Insulation Monitoring in ESS
    1. 2.1 Single Switch Topology
      1. 2.1.1 Test Steps
    2. 2.2 Dual Switch Floating Sampling Topology
      1. 2.2.1 Test Steps
    3. 2.3 Dual Switch Sampling in High Voltage Side Topology
    4. 2.4 AC Injection Topology
  6. 3Comparison of Designs
    1. 3.1 Injection Resistance Influence on Accuracy
  7. 4Capacitor Influence on Sampling Time
    1. 4.1 How to Choose Y Capacitor
    2. 4.2 Sampling Time
  8. 5Key Devices
    1. 5.1 BQ79731-Q1
    2. 5.2 UCC33421-Q1
    3. 5.3 AMC131M02
    4. 5.4 AMC3330
    5. 5.5 ISO773x
  9. 6Topos Simulation Result and Conclusion
  10. 7Summary
  11. 8References

AMC3330

The AMC3330 is a fully-differential precision isolated amplifier with high-input impedance, and an integrated DC/DC converter that allows the device to be supplied from a single 3.3V or 5V voltage supply source from the low voltage side. The input stage of the device drives a 2nd-order, delta-sigma (ΔΣ) modulator. The modulator uses an internal voltage reference and clock generator to convert the analog input signal to a digital bit stream. The drivers (termed TX in the Functional Block Diagram) transfer the output of the modulator across the isolation barrier that separates the high-side and low-side voltage domains. The received bit stream and clock are synchronized and processed by a 4th-order analog filter on the low-side and presented as a differential analog output.

The 1.2GΩ differential input impedance of the analog input stage supports low gain-error signal-sensing in high-voltage applications using high-impedance resistor dividers. The signal path is isolated by a double capacitive silicon-dioxide (SiO2) insulation barrier, whereas power isolation uses an on-chip transformer separated by a thin-film polymer as the insulating material.

 AMC3330 Functional Block
                    Diagram Figure 5-4 AMC3330 Functional Block Diagram