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TLV1117LV: Confirm no oscillation of output with a ceramic output capacitor on TLV1777LV.

Part Number: TLV1117LV

Hi,

Do you have any issue of the output oscillation with a ceramic output capacitor on TLV1777LV?

My customer faced the oscillation of output with a ceramic capacitor on competitor's LDO (BA15BC0FP-E2).   I understand TLV1117LV recommends a ceramic output capacitor and DOES NOT recommend an electrolytic output capacitor.  So I want to confirm whether there is no issue with a ceramic output capacitor on TLV1117LV.  Please advise us.

Also, if possible, could you please let us know the reason why TI recommend a ceramic output capacitor only?

Thanks and best regards,
M.HATTORI.

  • Hello Hattori-San,

                                As recommended in the Datasheet, please use a ceramic capacitor at the output pin (1uF or greater) to avoid any stability issues. This device is designed to be stable for output capacitors with very low ESR (even ESR = 0Ω). Electrolytic capacitors typically have larger ESR values than their ceramic counterparts. Larger ESR, could cause a 'Zero', and as a result higher frequency parasitic 'Poles', to fall within the Bandwidth of the LDO leading to instability. This is why we recommend that a ceramic capacitor be used, which would ensure that the 'Zero' introduced by the ESR of COUT (and subsequent parasitic 'Poles') fall outside the LDO bandwidth thereby help maintain stability. The following App note explains the impact of ESR in more detail: https://www.ti.com/lit/an/slyt187/slyt187.pdf?ts=1644196484731&ref_url=https%253A%252F%252Fwww.google.com%252F . Thanks!

    Regards,

    Srikanth