TIDUF28 November   2023

 

  1.   1
  2.   Description
  3.   Resources
  4.   Features
  5.   Applications
  6.   6
  7. 1System Description
    1. 1.1 Key System Specifications
  8. 2System Overview
    1. 2.1 Block Diagram
    2. 2.2 Highlighted Products
      1. 2.2.1 LMG3422R030
      2. 2.2.2 ISO7741
      3. 2.2.3 AMC1306M05
      4. 2.2.4 AMC1035
      5. 2.2.5 TPSM560R6H
      6. 2.2.6 TPSM82903
  9. 3System Design Theory
    1. 3.1 Power Switches
      1. 3.1.1 GaN-FET Selection Criterion
      2. 3.1.2 HVBUS Decoupling and 12-V Bootstrap Supply
      3. 3.1.3 GaN_FET Turn-on Slew Rate Configuration
      4. 3.1.4 PWM Input Filter and Dead-Time Calculation
      5. 3.1.5 Signal Level Shifting
      6. 3.1.6 LMG3422R030 Fault Reporting
      7. 3.1.7 LMG3422R030 Temperature Monitoring
    2. 3.2 Phase Current Sensing
      1. 3.2.1 Shunt
      2. 3.2.2 AMC1306M05 Analog Input-Filter
      3. 3.2.3 AMC1306M05 Digital Interface
      4. 3.2.4 AMC1306M05 Supply
    3. 3.3 DC-Link (HV_BUS) Voltage Sensing
    4. 3.4 Phase Voltage Sensing
    5. 3.5 Control Supply
    6. 3.6 MCU Interface
  10. 4Hardware, Software, Testing Requirements, and Test Results
    1. 4.1 Hardware Requirements
      1. 4.1.1 PCB
      2. 4.1.2 MCU Interface
    2. 4.2 Software Requirements
    3. 4.3 Test Setup
      1. 4.3.1 Precautions
      2. 4.3.2 Test Procedure
    4. 4.4 Test Results
      1. 4.4.1 24-V Input Control Supply
      2. 4.4.2 Propagation Delay PWM to Phase Voltage Switch Node
      3. 4.4.3 Switch Node Transient at 320-VDC Bus Voltage
      4. 4.4.4 Phase Voltage Linearity and Distortion at 320 VDC and 16-kHz PWM
      5. 4.4.5 Inverter Efficiency and Thermal Characteristic
        1. 4.4.5.1 Efficiency Measurements
        2. 4.4.5.2 Thermal Analysis and SOA Without Heat Sink at 320 VDC and 16-kHz PWM
  11. 5Design and Documentation Support
    1. 5.1 Design Files
      1. 5.1.1 Schematics
      2. 5.1.2 BOM
      3. 5.1.3 PCB Layout Recommendations
        1. 5.1.3.1 Layout Prints
      4. 5.1.4 Altium Project
      5. 5.1.5 Gerber Files
      6. 5.1.6 Assembly Drawings
    2. 5.2 Tools and Software
    3. 5.3 Documentation Support
    4. 5.4 Support Resources
    5. 5.5 Trademarks
  12. 6About the Author

1.1 Key System Specifications

SUBSECTIONPARAMETERSPECIFICATION
Input supplyDC-bus voltage320 V (TYP), 400 V (MAX)
Control supply voltage24 V ±20% (TYP), 60 V (MAX)
Power switchGaN-FETLMG3422R030, bottom-side cooling
Slew rate30 V/ns (TYP), configurable, 100 V/ns (MAX) with this design.
Overcurrent and overtemperature protectionLMG3422R030 integrated
Fault reportingOvercurrent, overtemperature, and UVLO fault feedback
Temperature sensing (phase V)Encoded: 9-kHz PWM at 3.3 V
3-phase complementary PWM8 kHz – 16 kHz (TYP), and higher, see section 3.
PWM dead time

150 ns (MCU), results effective 120 ns (TYP), can be lower, see Section 3.

3-phase output current (no heat sink)7.7 ARMS (TYP) at 27°C ambient, no heat sink
Heat sinkNone, but provision to add
Phase current sense Shunt1-mΩ shunt, 3 W
Isolated modulator±50 mV (linear input voltage range)
Measurement range

±50 A (linear range)

DC bus voltage senseMeasurement range0 V to 480 V (linear range), configurable
Phase voltage senseMeasurement range0 V to 480 V, configurable
IsolationNoneMCU connected to DC–, hot side control
MCU interfaceC2000 controlCARD180-pin HECC (5V supply and 3.3 V I/O)
MCU100-mil standard headers (3.3 V I/O)
PCBLayer stack6 layers, 70-μm copper
Clearance distances1. 6 mm (top and bottom layer), 0.6 mm (inner layers)
PCB size148 mm × 116 mm (5826 mil × 4566 mil )