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LP5907-Q1: Output Capacitor ESR for stability

Part Number: LP5907-Q1


The datasheet calls out the output capacitor ESR specified from a range of 5mOhm to 500mOhm. << image below >>

We're looking at using a ceramic capacitor which could have ESR specified as low as 2mOhm [ 10uF X7R ceramic – PN CGA4J1X7R0J106K ].

  • Is there a stability concern in this case?
  • Also does the ESR spec apply only to the actual input/output capacitors physically located near the regulator?  We have other bypass caps on the output, but they’re located further away, downstream of some trace resistance and inductance.

Thank you, Keith

  • Hi Keith,

    2mR is a bit critical. You could add a low ohmic resistance of 50mR...100mR in 0805 package in series to the cap to increase the ESR.

    If more than one decoupling cap is used, the total ESR of this parallel circuit should not go under 5mR. This can easily be fullfilled by using above low ohmic resistances in series to the caps. Or you can even use such a resistor to form a low pass filter in the supply line. Also by this the ESR of decoupling cap can be increased.

  • Hi Keith,

    In addition to the comments made by  kai klaas69 (5218539), please also ensure that the total capacitance on OUT does not exceed 10 uF.

    Very Respectfully,