TPS65220: TPS6522053 LDO3 slow ramp up

Hello Thierry HAUSER

Could you please provide a capture of the below for the team to verify.

Regards,

Sreenivasa

Hello Sreenivasa,

98% of 1.8V= 1.764V

So rise time is about 972µs on EVM SK_AM64B: 

Hello Thierry HAUSER

Thank you.

I cant see the EN signal.

Please help me understand if you captured with respect to the enable signal.

Regards,

Sreenivasa

Hello Sreenivasa,

There is no specific enable for LDO3 because timing is managed internally by TPS6522053.

Nevertheless please find global EVM SK_AM64B enable signal : TPS6522053_EN

Hello Thierry HAUSER

Thank you.

Based on the EN threshold, the timing looks to be for the slow ramp.

I will assign to the PMIC team to provide additional thoughts.

Regards,

Sreenivasa

Hello Sreenivasa,

My purpose is only about  LDO3 ramp up timing which should be around ~3ms according to TRM.

I don't talk about relationship between TPS6522053_EN and LDO3 rampup.

According to Figure 2.1 of TRM, it makes sense that LDO3 rampup should be lower than 3ms in order to  let BUCK3 not arriving at the same time!

So I guess there is an errata into the meaning of the bit LDO Ramp Configuration.

Hello Thierry HAUSER

Thank you.

As i understand the 3 ms is the time between start of the ramps for 2 different supply rails. - in this case LDO3 and BUCK3.

I would expect the LDO3 ramp to be less that 3 ms for the next supply ramp to start and the measurements seems to match.

Regards,

Sreenivasa

Hello Sreenivasa,

Ok I understand your point of vue.

So into the TRM, slow ramp up time is defined as ~3ms

and into the Datasheet, slow ramp up time is defined with a max of 2.3ms.

Is it right?