TPS62810EVM-015: Best way to reduce overshoot/undershoot

Youhei Miyaoka

Intellectual 2105 points

Part Number: TPS62810EVM-015
Other Parts Discussed in Thread: TPS62810-Q1

Hi team,

My customer want to improve SW overshoot/undershoot.

Conditions: Vin = 3.3V, Vout = 1.8V, Iout = 1.8A, COMP/FSET = GND, MODE/SYNC = 3.3V(Vin)

The other setting is default. They measured SW pin.

I have some questions on this.

1. At first, is it correct to measure at SW pin not at output?

2. If #1 is yes, how to improve this overshoot/undershoot. I think one of the idea is to increase capacitance. Is this best idea?

Regards,

Youhei MIYAOKA

6 months ago

0 Febin 6 months ago

TI__Mastermind 21150 points

Hi Youhei,

I would like to share some App notes to help you.

https://www.ti.com/lit/an/slva494a/slva494a.pdf?

https://www.ti.com/lit/an/slyt465/slyt465.pdf?

Thanks,

Febin

0 Youhei Miyaoka 6 months ago in reply to Febin

TI__Intellectual 2105 points

Hi Febin,

Thank you. The customer measured using wrong GND.

But their measurement data is still large overshoot/undershoot. Could you check waveform / measurement method and give us feedback?

Regards,

Youhei MIYAOKA

+1 Febin 6 months ago in reply to Youhei Miyaoka

TI__Mastermind 21150 points

Hi Youhei,

As per the scope plot, the SW AC spikes reaches ~ +5V and ~ -1.2V.

This is acceptable and is within the recommended limits for the device.

Regards,

Febin

0 Youhei Miyaoka 6 months ago in reply to Febin

TI__Intellectual 2105 points

Hi Febin,

Thanks. I understood this overshoot is within datasheet specification.

In my understanding, it is difficult to improve this overshoot in TPS62810-Q1, is it correct?

Regards,

Youhei

0 Febin 6 months ago in reply to Youhei Miyaoka

TI__Mastermind 21150 points

Hi Youhei,

Who is the customer, EE?

What is the status of the project? Can they change the layout now?

Regards,

Febin

0 Youhei Miyaoka 6 months ago in reply to Febin

TI__Intellectual 2105 points

Hi Febin,

I will send customer information internally after that.

This measurement result is on EVM SW pin, not their circuit.

They are considering to use this device for their VAVE project.

Regards,

Youhei

+1 Febin 6 months ago in reply to Youhei Miyaoka

TI__Mastermind 21150 points

Hi Youhei,

Thanks for all the info.

We could control the ringing using an additional snubber. However, do they really need this? Do they have any problem in their application due to this?

Regards,

Febin

Power management

Power management forum

TPS62810EVM-015: Best way to reduce overshoot/undershoot