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SamGibson ♦
SamGibson ♦
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Some practical considerations:

  1. In a switching converter, you may have a minimum off time (e.g., half bridge which has deadtime requirements). This, in conjunction with switching frequency, can limit duty cycle to a practical maximum near but less than 100%.
  2. Some converter topologies/control mechanisms have stability limitations that require/warrant staying below 50% duty cycle (e.g., peak current controlled flyback/similar as discussed in http://www.ti.com/lit/an/snva555/snva555.pdf)
  3. Some gate drivers may not be able to operate at 100% duty cycle (e.g., if using a bootstrap capacitor in a high-side gate driver, the cap will eventually bleed down to 0V).

You can generally run an IGBT continuously within its safe operating area - review voltage, current, and thermal ratings. If the load in your circuit is resistive, that would be fairly straightforward so long as switching speed and L*di/dt's are considered.

If you are going topto run your IGBT anat much lower switching frequencies and have real reliability concerns, I'd also look at thermal cycling considerations.

Some practical considerations:

  1. In a switching converter, you may have a minimum off time (e.g., half bridge which has deadtime requirements). This, in conjunction with switching frequency can limit duty cycle to a practical maximum near but less than 100%.
  2. Some converter topologies/control mechanisms have stability limitations that require/warrant staying below 50% duty cycle (e.g., peak current controlled flyback/similar as discussed in http://www.ti.com/lit/an/snva555/snva555.pdf)
  3. Some gate drivers may not be able to operate at 100% duty cycle (e.g., if using a bootstrap capacitor in a high-side gate driver, the cap will eventually bleed down to 0V).

You can generally run an IGBT continuously within its safe operating area - review voltage, current, and thermal ratings. If the load in your circuit is resistive, that would be fairly straightforward so long as switching speed and L*di/dt's are considered.

If you are going top run your IGBT an much lower switching frequencies and have real reliability concerns, I'd also look at thermal cycling considerations.

Some practical considerations:

  1. In a switching converter, you may have a minimum off time (e.g., half bridge which has deadtime requirements). This, in conjunction with switching frequency, can limit duty cycle to a practical maximum near but less than 100%.
  2. Some converter topologies/control mechanisms have stability limitations that require/warrant staying below 50% duty cycle (e.g., peak current controlled flyback/similar as discussed in http://www.ti.com/lit/an/snva555/snva555.pdf)
  3. Some gate drivers may not be able to operate at 100% duty cycle (e.g., if using a bootstrap capacitor in a high-side gate driver, the cap will eventually bleed down to 0V).

You can generally run an IGBT continuously within its safe operating area - review voltage, current, and thermal ratings. If the load in your circuit is resistive, that would be fairly straightforward so long as switching speed and L*di/dt's are considered.

If you are going to run your IGBT at much lower switching frequencies and have real reliability concerns, I'd also look at thermal cycling considerations.

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MondayTuesdayWednesday
MondayTuesdayWednesday
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Some practical considerations:

  1. In a switching converter, you may have a minimum off time (e.g., half bridge which has deadtime requirements). This, in conjunction with switching frequency can limit duty cycle to a practical maximum near but less than 100%.
  2. Some converter topologies/control mechanisms have stability limitations that require/warrant staying below 50% duty cycle (e.g., peak current controlled flyback/similar as discussed in http://www.ti.com/lit/an/snva555/snva555.pdf)
  3. Some gate drivers may not be able to operate at 100% duty cycle (e.g., if using a bootstrap capacitor in a high-side gate driver, the cap will eventually bleed down to 0V).

You can generally run an IGBT continuously within its safe operating area - review voltage, current, and thermal ratings. If the load in your circuit is resistive, that would be fairly straightforward so long as switching speed and L*di/dt's are considered.

If you are going top run your IGBT an much lower switching frequencies and have real reliability concerns, I'd also look at thermal cycling considerations.