TPS61288: SOO mode

Tommy Tzeng

Genius 4805 points

Part Number: TPS61288

Hi Sir,

may we understand this SOO mode,

under normal circumstance, the ripple of PFM is large than PWM? right.

but because TPS61288 has SOO mode, it can make PFM ripple smaller than PWM? under light load.

over 1 year ago

0 Fergus He over 1 year ago

TI__Genius 9780 points

Hi Tommy,

SOO and the ripple are not directly related.

SOO mode is mainly focused on the seamless transition from PWM to PFM operation.

the ripple current is influenced by the peak current, which will decrease with the output of the internal error amplifier decreases (related to load).

The smaller ripple is compared with those ripple that only use voltage loop in the light load

Best Regards

Fergus

0 Tommy Tzeng over 1 year ago in reply to Fergus He

Genius 4805 points

Hi Fergus,

ok~got it,

we simulate light load at 80mA, why webench is no value of Vin and Vout ripple? just know in PFM mode.

WBDesign226_tps61288 lightload.pdf

but 160mA can be simulate ripple, as attach below.

WBDesign231_tps61288 160mA.pdf

0 Fergus He over 1 year ago in reply to Tommy Tzeng

TI__Genius 9780 points

Hi Tommy,

Sorry I'm not sure why the webench show the different result, but you could use the PSpise model (download in website) to simulate the result.

Best Regards

Fergus

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TPS61288: SOO mode