Hi,
I'm simulating the step-down regulator LT3502 in LTSpice and don't know what to think of the thermal part. In the attached screenshot you can see a graph of what the IC itself dissipates. Sure peaks of up to 28 W are high, this would give a junction temperature of 28W * 110°C/W = 3080 °C > 125 °C, the maximum junction temperature (let's say we can neglect the ambient temperature here lol).
When I calculate the average of the graph you see, it is only 0.315 W, so 0.315 W * 110°C/W = 34°C, perfectly acceptable.
How do you decide on what is acceptable and what not?
I'm simulating the step-down regulator LT3502 in LTSpice and don't know what to think of the thermal part. In the attached screenshot you can see a graph of what the IC itself dissipates. Sure peaks of up to 28 W are high, this would give a junction temperature of 28W * 110°C/W = 3080 °C > 125 °C, the maximum junction temperature (let's say we can neglect the ambient temperature here lol).
When I calculate the average of the graph you see, it is only 0.315 W, so 0.315 W * 110°C/W = 34°C, perfectly acceptable.
How do you decide on what is acceptable and what not?
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