Alternatives to pwm power supply

[Kardo22]

Hi
I was wondering if anyone knew what alternative ways are out there to control switching power supplies?
A guy was telling me about computer power supplies and mentioned that there is some new kind instead of PWM that was much more efficient on low power. But I have completely forgotten what it was.
Can anyone help me remember?
Thanks

 

[(*steve*)]

Switch mode power supplies don't necessarily use PWM (They might, or they might use something similar, but strictly speaking, different).

There are numerous topologies and they may have different efficiencies at different loads but I can't make any firm suggestion.

 

[Kardo22]

It was some topology that is replacing PWM in high-end computer power supplies. I remember he said its more efficient than PWM when the computer load is small. I haven't found anything from google, I probably don't know correct keywords to use.
Anyone heard about sth that is taking over from PWM in computer power supplies?

 

[KrisBlueNZ]

He might be referring to synchronous rectification I guess, or current mode control?

 

[(*steve*)]

Synchronous rectification is certainly something which increases efficiency, but is most significant for low voltage outputs. It's certainly something you would want to feature on a low voltage, high current power supply (CPU core voltages come to mind).

I'm not sure it matches what the OP has specifically asked about, but with slight rewording (low voltage vs. low power) it does.

 

[KrisBlueNZ]

Yeah. I was just throwing out some terms in case the OP recognised them.

Synchronous rectification isn't an alternative to PWM either, but when you're new to the terminology it's easy to get a bit confused.

 

[Kardo22]

Thanks
Got some interesting reading from your suggestions