LMZ21701: :

Onur Kusakoglu

Part Number: LMZ21701
Other Parts Discussed in Thread: TPS62150

Good morning,

I am planning to use LMZ21701 on my design to generate 4 different power rails.

With TI Webench tool I can't do simulation below 300mA load values. 3 of may voltage rail loads are a round 300mA so they are okay.

One of my application requires only 30mA continuous from 1V2 voltage rail. My input voltage to LMZ21701 is 5V.

I see from the datasheet that it is doable. There is also a PWM and PSM modes.

If 30mA falls into PSM mode, then is there going to be a pulse skipping in order to generate the needs? Pulse skipping may have bad impact to EMI?

over 4 years ago

0 Lishuang Zhao over 4 years ago

TI__Expert 7500 points

Hi,

We are looking into it, will feedback to you soon.

Thanks,

Lishuang

0 Jean Picard over 4 years ago

TI__Intellectual 1125 points

Onur Kusakoglu

Hello

At such low output current, you can expect PSM operation (Power Save mode). Basically, the transition is seamless between PWM and PSM, following load level.

That means that it wait for a longer time before reapplying the next ON time period. The approach used with DCS control minimizes EMI when compared with other approaches (bursts for example).

Here is a link to an app note on this subject.

Regards

Jean