• State Resolved
  • Locked Locked
  • Replies 2 replies
  • Subscribers 63 subscribers
  • Views 464 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.

TPS63036 90mV ripple

Travis Ray
Prodigy 80 points
Other Parts Discussed in Thread: TPS61040, TPS63036, TPS63050

I'm trying to replace a TPS61040 with a TPS63036 to power my MCU and a couple of other lower power digital/analog components. In my testing of the latest board I'm seeing ~90mV ripple at low current in my application (3-10mA) which seem high to me. Is this normal?

Other specs

Vin: 1.8 - 5v

Vout: 3.3

I've also tried adding resistor load of about 150mA and it still has the same pk-pk ripple just faster.

Also tried with and without 10pF bypass cap on R1 (from datasheet).

At low load the ripple frequency is about 10ms I do have the power save enabled (grounded) but its baked into my circuit and I don't think I can modify without another board revision. I need to know if this is expected behaviour so I can take a different route.

Thanks,

Travis

  • 0
    Prodigy 80 points

    Forgot to mention its setup like the datasheet example.

    1.5uH inductor

    3x 10uF caps on vout (plus several other 10uF and .1uF decoupling on most of the IC's)

    1x 10uF cap on vin

  • 0 in reply to Travis Ray
    TI__Expert 7110 points

    For your condition, the device is operating in power safe mode. (described on page 14 of the Datasheet). The ripple you measured is expect-able for low currents.

    You can get rid of the ripple by disabling the power safe mode.

    Another option could be using the newer TPS63050. This device has a minimum input voltage of 2.5V. Is your 1.8V a absolute requirement?

    What is your requirement to the ripple performance?