• State TI Thinks Resolved
  • Locked Locked
  • Replies 2 replies
  • Answers 1 answer
  • Subscribers 63 subscribers
  • Views 294 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TPS745-Q1: Is TPS745-Q1 more prone to overshoot than other LDOs?

AnBer
Mastermind 30110 points
Part Number: TPS745-Q1
Other Parts Discussed in Thread: TPS745

Team,

I have seen the Avoid Start up in LDO (https://www.ti.com/lit/pdf/sbva060 ) -Is TPS745-Q1 more prone to overshoot than other LDOs?

-In this design(with 3.3Vout, DRB package) the overshoot should not exceed 3.6V.
Could you do a schematics/PCB layout review to assess if some improvement need to be made?

Thanks in advance,

A.

  • 0
    TI__Mastermind 37005 points

    Hello Anber,

    Yes we can review the schematic and layout if it is provided.  I would say that the TPS745 is not more or less prone to overshoot than any typical linear regulator.  As shown in the app note you linked, if the input supply ramps too quickly then the output can turn on while the device is in dropout.  Section 8.1.4 in the TPS745 datasheet also discusses this.  If you are concerned about overshoot then let Vin ramp to steady state, then enable the TPS745 using the EN pin.  This will remove any overshoot issues (see figure 36 for an example in the datasheet).

    Thanks,

    - Stephen

  • 0 in reply to Stephen Ziel
    TI__Mastermind 30110 points

    Thanks for the help/feedback you provided offline.

    Adding the DC/DC PG to LDO EN trace on PCB seems to be the easiest option as one single resistor need to be added.

    An RC circuit would require 2 additional components.

    Thanks again.

    A.