TPS746-Q1: VRM parameter for signal integrity simulation

Hi Asif,

I'm looking into this. I'll get back to you in 1-2 business days. 

Regards,

Nick

Hi Nick,

Thanks for acknowledging the post.

Did you manage to get the requested parameters for VRM modeling?

Regards,

Asif P N

Hi Nick,

Could you please provide an update on this query?

Regards,

Asif P N

Hi Asif,

So sorry for the delay. Can you please describe the parameters you need in more detail? I think the Lout and R0 seem relatively straightforward (I'm thinking a first-order-approximated supply output impedance), but I'm not sure about the Lslew and Rflat parameters. Which software package are you using for your signal integrity analysis? 

Thanks,

Nick

Hi Nick,

Thanks for your response.

We are using Ansys SIwave for signal integrity analysis. Ro and Lout are output resistance and inductance respectively.

Lselw and Rflat are used to model the transient behavior of the VRM.

Typical equivalent circuit snap from the tool is attached here for your reference.

Related article on this VRM modeling: - Design a VRM with perfectly flat output impedance in 5 seconds or less - EDN

Regards,

Asif P N

Hi Asif,

Thanks, I will review this and see what I can do to get these values.

Regards,

Nick

Hi Nick,

We are starting the SI simulation of the board today. Will you please help us with the requested inputs at the earliest?

Regards,

Asif P N

Hi Asif,

I apologize once again, I am trying to simulate the output impedance so I can start constructing the VRM model. I'm hoping to have something to share before the weekend. 

Regards,

Nick

Hi Asif,

Just wanted to update you on this. I don't have the parameter values yet, but I'm making progress on it. I hope to have them in the next couple of days. 

Regards,

Nick

Hi Asif,

What is your expected load current? The parameters have a strong dependence on the load. 

Regards,

Nick

Hi Nick,

Thanks for your update.

Estimated Current Consumption is 300mA.

I hope this helps for your modeling.

Regards,

Asif P N

Hi Nick,

Thank you for your time and consideration.

Regards,

Asif P N