EEVblog Electronics Community Forum
Electronics => Beginners => Topic started by: mechorican on November 19, 2023, 12:00:55 pm
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Hi,
I'm looking for a boost converter with the following specifications:
Vin: 24V
Vout 40V - 42V
adjustable output current limit(200mA - 250mA)
Can somebody help me with a suggestion? Thank you very much.
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What's it for?
The current limit won't work if the output voltage falls below the input voltage, because the output is always connected to the input, via a forward biased diode and inductor.
(https://upload.wikimedia.org/wikipedia/commons/thumb/3/39/Boost_conventions.svg/330px-Boost_conventions.svg.png)
https://en.wikipedia.org/wiki/Boost_converter?useskin=vector
If it's for over-current protection, a fuse is the only way.
If it's to power LEDs, then the forward voltage must always be greater than the maximum input voltage.
Use a different topology, (flyback transformer, SEPIC, buck-boost etc.) for current limiting, at output voltages lower, than the input voltage.
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The boost converter can limit current at the boosted voltage, but by itself it cannot limit current once Vout falls below Vin. There are a number of ways to do that but it takes added hardware such as another series FET which "open circuits" when the current limit is exceeded.
I think there are some ICs out there which offer that functionality....look at Tea Eye.