LM2577 input current!

Hi guys, how much is the maximum input current? for LM2577-ADJ, I need to power it with a 20 Amp 12v and have a 15v output with a maximum consumption of 600 milliamps. What worries me is the incoming current.

Regardless of how much current a power supply can deliver, it can’t force more current into a device than the device wants (refer to ohm’s law).

So, as long as the power supply maintains a stable voltage within the range allowed by the device being powered, connecting a 10A, 20A or 100A power supply to a device that wants 1A will result in all those power supplies delivering 1A to the device.

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So with an input of 20A 50A it is enough that the device connected to the output consumes no more than 1A, right?


Ohms law states that current is equal to voltage divided by resistance. The power supply provides the voltage and the load (LM2577 input) is the resistance.

Now it’s clearer, thank you!