u/AmeliaBuns

I have a 100W LED and I'd like to PWM dim it at around 3KHz to prevent headaches, 25KHz would be ideal because of the potential auditable noise but that might be too high for such a power hungry LED.

My problem is figuring out how much heat would go through the FET. Assuming 2.5A (LED Current) and 50-40mOhm I'd assume it'd not be more than 0.3w at 4KHz. But the issue is I have to keep in mind the reality, driver stability time, output capacitance and so on. Right now I think I can reach a good output with a 12uF of capacitance but maybe I could just go with 4.7uF. I'm not sure how I'd calculate the power generated from the short and everything else.

Is shunt dimming a practical method at such high wattages? Should I just give up and do 250Hz dimming with the good old EN pin PWMing?

Hi. I have a 100W LED and I'd like to PWM it at around 3000KHz to prevent headaches, 25,000KHz would be ideal because of the potential auditable noise.

My problem is figuring out how much heat would go through the FET. Assuming 2.5A (LED Current) and 50-40mOhm I'd assume it'd not be more than 0.3w at 4KHz. But the issue is I have to keep in mind the reality, driver stability time, output capacitance and so on. Right now I think I can reach a good output with a 12uF of capacitance but maybe I could just go with 4.7uF. I'm not sure how I'd calculate the power generated from the short and everything else.

Is shunt dimming a practical method at such high wattages? Should I just give up and do 250Hz dimming?