Figure 4-4 shows CLLLC operation at 19 A (6.6 kW) under the following parameters:

• Traces
  • C1: GaN Primary Switch Node Drain Voltage
  • C2: GaN Secondary Switch Node Drain Voltage
  • C3: Transformer Primary Current
  • C4: Transformer Secondary Current
• Conditions
  • V_IN = 400 V
  • V_OUT = 350 V
  • I_OUT = 19 A

Figure 4-5 shows CLLLC operation at 10 A and the following parameters:

• Traces
  • C1: GaN Switch Node Drain Voltage Leg 1
  • C2: GaN Switch Node Drain Voltage Leg 2
  • C3: Transformer Primary Current
  • C4: Transformer Secondary Current
• Conditions
  • V_IN = 400 V
  • V_OUT = 350 V
  • I_OUT = 10 A

A zoom-in of the GaN switch drain-to-source voltage transition is shown to be approximately 40 ns in Figure 4-6. This rapid transition comes from the low C_OSS of the LMG3522.

The waveform in Figure 4-6 is measured using the following parameters:

• Traces
  • C1: GaN Switch Node Drain Voltage Leg 1
  • C2: GaN Switch Node Drain Voltage Leg 2
  • C3: Transformer Primary Current
  • C4: Transformer Secondary Current
• Conditions
  • V_IN = 400 V
  • V_OUT = 350 V
  • I_OUT = 10 A

The waveform in Figure 4-7 is measured using the following parameters:

• Traces
  • C1: GaN Switch Node Drain Voltage Leg 1
  • C2: GaN Switch Node Drain Voltage Leg 2
  • C3: Transformer Primary Current
  • C4: Transformer Secondary Current
• Conditions
  • V_IN = 400 V
  • V_OUT = 350 V
  • I_OUT = 2 A

A zoom-in of the GaN switch drain-to-source voltage transition is shown to be approximately 75 ns in Figure 4-8. This rapid transition comes from the low C_OSS of the LMG3522. The slightly longer transition time in this image comes from the lighter load condition and the resulting reduced current flow.

The waveform in Figure 4-8 is measured using the following parameters:

• Traces
  • C1: GaN Switch Node Drain Voltage Leg 1
  • C2: GaN Switch Node Drain Voltage Leg 2
  • C3: Transformer Primary Current
  • C4: Transformer Secondary Current
• Conditions
  • V_IN = 400 V
  • V_OUT = 350 V
  • I_OUT = 2 A