SDAA154 October   2025 AMC0300D , AMC0300D-Q1 , AMC0300R , AMC0306M05 , AMC0306M05-Q1 , AMC0306M25 , AMC0306M25-Q1 , AMC131M03 , AMC131M03-Q1 , AMC3301 , AMC3301-Q1 , AMC3302 , AMC3302-Q1 , AMC3306M05 , AMC3306M05-Q1 , AMC3306M25 , AMC3306M25-Q1

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2Detailed Description
    1. 2.1 Cost Optimized Power Supplies
      1. 2.1.1 Transformer Winding
      2. 2.1.2 Gate Driver Supply with Zener Diode
      3. 2.1.3 Gate Driver Supply with LDO
    2. 2.2 Simplified Power Supplies:
      1. 2.2.1 Integrated DC/DC Converter Power Supply
      2. 2.2.2 Discrete Transformer
    3. 2.3 Isolated Current Sensing Locations in High Voltage Power Conversion
      1. 2.3.1 Introduction
      2. 2.3.2 Rectifier (AC to DC Converter)
      3. 2.3.3 DC/DC
      4. 2.3.4 Inverter (DC to AC Converter)
  6. 3Summary
  7. 4References

2.2.1 Integrated DC/DC Converter Power Supply

Integrated DC/DC Converter Supply SchematicFigure 2-4 Integrated DC/DC Converter Supply Schematic

The integrated DC/DC converter power supply provides the highest ease of use amongst the five power supply options provided in this application note and contains a small footprint. The AMC33xx device family feature this power supply option and are an all-encompassing current or voltage sensing design. The family feature a fully integrated, isolated DC/DC converter that allows single-supply operation from the low-side power of the device to the high-side power of the device. This offers advantages in space constrained applications due to the limited need for external circuitry. Additionally, the integrated DC/DC converter offers diagnostic output to assist in monitoring that the device is operational and that the output voltage is valid. The diagnostic, DIAG, pin remains low until the high-side power is available. This facilitates in validating proper functioning of each power supply. Integrated DC/DC converters are useful in applications that prioritize power efficiency where only one power supply is available.

Figure 2-4 demonstrates a typical application schematic with the AMC3301-Q1 isolated amplifier. This device requires only very simple external circuitry. Namely, decoupling capacitors on the power pins on both the primary and secondary side, as well as a shunt or sensing resistor to frame the input to the device's full-scale input. Input filtering is recommended but not required depending on a given system and input source. The AMC3301EVM Evaluation Board EVM outlines the recommended design considerations and typical circuitry in more detail.