The LM2596 clone is the default answer to “I need 5V from 12V.” I measured ripple, efficiency, and thermal behaviour across four sellers at a 2A load to find where the cheap ones fall apart.
| seller | efficiency | ripple | verdict |
|---|---|---|---|
| Seller A | 84% | 28 mV | good |
| Seller B | 79% | 61 mV | noisy |
| Seller C | 82% | 35 mV | good |
| Seller D — “3A” | 71% | 90 mV | sags @ 2A |