SD540 Motor Controller

[Daniel_LaFleur]

Originally Posted by pnitin

All FRC the controller on market use synchronous rectification,
they are not linear converter, so what is mentioned above is incorrect.
for example, consider your cellphone charger 115V In 5V Out @ 1A current,.
According to your theory it should dissipate 110W and should melt, but it does not. It dissipate much low power since it uses switching topology.

Incorrect.

The output is 5VDC@1A not the input. The input is closer to 115VAC@0.05A or ~6Watts (assuming 1W inefficiency which is actually high).

In a phone charger (or most other chargers/USB power supply sources) you have a AC to DC converter (most likely a bridge rectifier). Then you have a buck converter (probably a transformer) and a switcher boost (High speed MosFET, inductor, and shottkey diode).