TPS7A6650EVM: TPS7A6650-Q1 Automotive, 150mA, Regulated input

Part Number: TPS7A6650EVM

Good day,

I was reading the device datasheet, TPS7A6xxx-Q1 High-Voltage Ultralow-I(q) Low-Dropout Regulator, but I found this paragraf in page 19:

"9 Power Supply Recommendations Design of the device is for operation from an input voltage supply with a range between 4 V and 28 V. This input supply must be well regulated."

My question is, if the device is designed wit automotive quality Q1, it is not supose to be for noisy enviroments as those give it by a car battery? Or, if I missunderstood what the quoted paragraph before means, could you please explain?

Thanks.

ANDRÉS FELIPE RODRÍGUEZ GIL.

4 Replies

  • Hi Andrés,

    This section is meant to communicate that the upstream supply to TPS7A66-Q1 will have an impact on the overall system performance. The LDO will still operate in noisy environments; however, the better the supply is regulated, the cleaner the LDO output will be. If the input to the LDO is moving around, the output of the LDO will also move as shown in the line transient response (figures 13 and 14).

    Very Respectfully,
    Ryan
  • In reply to Ryan Eslinger:

    Hi Ryan,

    How do you thing I can solve this? Maybe a supressor diode would be enough to avoid problems by the transient signal?

    Thanks for your answer.

    ANDRÉS FELIPE RODRÍGUEZ GIL
  • In reply to Andres Rodriguez:

    Hi Andrés,

    Anything you add upstream from the LDO to slow down or limit the magnitude of a line transient will improve the overall system performance including localized capacitors at the input pin of the TPS7A66-Q1 and/or filters. The transient response of an LDO improves as the transient magnitude and the ramp rate of the transient are decreased.

    Very Respectfully,
    Ryan
  • In reply to Ryan Eslinger:

    Hi Ryan,

    I Appreciate your answers and I will find the beter way to reduce the transient.

    Thanks for your  help

    ANDRÉS FELIPE RODRÍGUEZ GIL.