SLVUCQ2A july   2023  – july 2023 TPSF12C1 , TPSF12C1-Q1

 

  1.   1
  2.   Description
  3.   Get Started
  4.   Features
  5.   Applications
  6.   6
  7. 1Evaluation Module Overview
    1. 1.1 Introduction
    2. 1.2 Kit Contents
    3. 1.3 Specifications
    4. 1.4 Device Information
    5.     General Texas Instruments High Voltage Evaluation (TI HV EVM) User Safety Guidelines
  8. 2Hardware
    1. 2.1 EVM Description
    2. 2.2 Setup
    3. 2.3 Header Information
    4. 2.4 EVM Performance Validation
    5. 2.5 AEF Design Flow
      1. 2.5.1 AEF Circuit Optimization and Debug
  9. 3Implementation Results
    1. 3.1 EMI Performance
    2. 3.2 Thermal Performance
    3. 3.3 Surge Immunity
    4. 3.4 SENSE and INJ Voltages
    5. 3.5 Insertion Loss
    6. 3.6 Passive vs. Active Solution Comparison
  10. 4Hardware Design Files
    1. 4.1 Schematic
    2. 4.2 Bill of Materials
    3. 4.3 PCB Layout
      1. 4.3.1 Assembly Drawings
      2. 4.3.2 Multi-Layer Stackup
  11. 5Compliance Information
    1. 5.1 Compliance and Certifications
  12. 6Additional Information
    1.     Trademarks
  13. 7Related Documentation
    1. 7.1 Supplemental Content
  14. 8Revision History

3.6 Passive vs. Active Solution Comparison

Table 4-4 captures the applicable parameters for the CM chokes in equivalent passive and active EMI filter designs when installed with two 12-mH and 2-mH chokes, respectively. The active design achieves a 60% total copper loss reduction at 10 ARMS (PCU = 6 W – 2.4 W = 3.6 W, neglecting the winding resistance increase due to temperature rise), which implies lower component operating temperatures, reduced heatsinking requirement, and improved capacitor lifetimes. The footprint, volume and weight of the chokes reduce by 41%, 52% and 62%, respectively.

Table 3-1 CM Choke Comparison in Equivalent Passive and Active Filter Designs
FILTER DESIGN CM CHOKE PART NUMBER(1) QTY LCM (mH)(2) WINDING DCR (mΩ) SIZE (mm) TOTAL MASS (g) TOTAL POWER LOSS at 25°C (W)
Passive 7448051012 2 12 15 23 × 34 × 33 72 6.0
Active 7448031002 2 2 6 17 × 23 × 25 20 2.4
(1) Manufactured by Würth Elektronik.
(2) Refer to the white paper, How Active EMI Filter ICs Mitigate Common-Mode Emissions and Save PCB Space in Single- and Three-Phase Systems, for more detail on these passive and active solutions.

Derived from the Würth Elektronik REDEXPERT tool, Figure 4-9 provides impedance curves for the CM chokes mapped out above. The curves highlight that the smaller-size 2-mH choke has a higher self-resonant frequency (SRF) and improved high-frequency performance.

As an example of the higher CM impedance at high frequencies due to lower intrawinding capacitance, the impedance of the CM choke at 30 MHz increases from 150 Ω to 2.2 kΩ (when going from 12 mH in the passive design to 2 mH in the active design). The × and o markers shown at 10 MHz and 30 MHz in Figure 4-9 demarcate the respective CM impedances for the passive and active designs. The higher choke impedance evident above 4 MHz for the active design may obviate the need for grid-side Y-capacitors (typically installed for high-frequency attenuation).

GUID-20230701-SS0I-G3J5-KML0-TSFFXZ9LWHC4-low.svg Figure 3-9 Impedance Characteristics of the Selected CM Chokes in the Passive Design (2 × 12 mH) and the Active Design (2 × 2 mH)