WEBENCH® Tools/TPS57160-Q1: Selecting specific switching frequency on TI Webench impossible?

Peter C

Part Number: TPS57160-Q1

Tool/software: WEBENCH® Design Tools

Hi,

When trying to design a converter around the TPS57160-Q1, I am unable to select the entire switching frequency range in Webench. I would like to select a switching frequency of approx 1220kHz(random number), which I can enter during the initial specification of the converter parameters(at the "front page", where I enter input/output voltage, current, etc). But once in the "customize" tab of Webench, I can't change the "user preferred switching frequency" to any number larger than 838.024khz:

The TPS57160 should be able to do up to 2500kHz, so why can't I enter this value? The Rt resistor is set correctly to approx. 90kohm, according to what I entered during the initial specification, but I can't change the switching frequency freely, which is really annoying.

over 5 years ago

0 Samuel Jaffe over 5 years ago

TI__Mastermind 25590 points

Peter,

Please share your design so we can take a look. I was able to create a design which can sync up to 1.6MHz. Still not 2.5MHz. I'll get in contact with the WEBENCH team to sort this out.

Thanks,

-Sam

0 Peter C over 5 years ago in reply to Samuel Jaffe

Prodigy 200 points

Hi Sam,

There is no specific design. The 838.024kHz applies to all designs based on the TPS57160-Q1. It may also apply to designs with other devices(haven't checked). Yes, you can set a different switching frequency at the beginning and it will carry through to the design(by assigning the right value to the Rt resistor), but once you are in the tab pictured in my previous post, you can't set the switching frequency to any larger number than 838.024kHz.

Sincerely,

Peter

0 Samuel Jaffe over 5 years ago in reply to Peter C

TI__Mastermind 25590 points

Peter,

I have found the max available frequency changes with the input specs. I've reached out to the WEBENCH guru to address this. They will be back on Monday and we should have an answer by Monday or Tuesday.

Thanks,

-Sam

0 Samuel Jaffe over 5 years ago in reply to Samuel Jaffe

TI__Mastermind 25590 points

Peter,

They explained that max frequency is based on a calculation which takes into consideration temperature, min on time, and min off time.

We're looking into this calculation to see what's causing this limitation.

-Sam

0 Samuel Jaffe over 5 years ago in reply to Samuel Jaffe

TI__Mastermind 25590 points

Peter,

This frequency reduction is for short circuit protection as explained in section 8.3.11 of the datasheet. You can operate at a higher frequency by changing values in WEBENCH manually and validating that your inductor does not saturate and the system will not become damaged in the event of a short circuit.

-Sam

0 Peter C over 5 years ago in reply to Samuel Jaffe

Prodigy 200 points

Hi Sam, thanks for your answer.

I was not aware that the max user preferred frequency was dependent on the component values of the circuit. Thanks for your reply!

Power management

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WEBENCH® Tools/TPS57160-Q1: Selecting specific switching frequency on TI Webench impossible?