Hi,
When using linear regulators, I have always been told that to ensure the output is stable, to use a resistor of about 1Ohm in series with the output if using MLCC type capacitors, either X7R or C0G, since their own output ESR is so low.
In more modern day LDO data sheets I never see anything like this, and also there is no description about a minimum ESR for the supply to be clean and stable. What does everyone else here do when designing an LDO? is it prudent to have a DNP component in series with the C0G/X7R capacitors, such that a 1R resistor can be soldered in if it is found the supply is not stable.
Additionally: why does this ESR limit only exist on the output of an LDO? Why is there no such requirement for a certain level of ESR for stability on the regulator input capacitors?
Regards,
SIC
When using linear regulators, I have always been told that to ensure the output is stable, to use a resistor of about 1Ohm in series with the output if using MLCC type capacitors, either X7R or C0G, since their own output ESR is so low.
In more modern day LDO data sheets I never see anything like this, and also there is no description about a minimum ESR for the supply to be clean and stable. What does everyone else here do when designing an LDO? is it prudent to have a DNP component in series with the C0G/X7R capacitors, such that a 1R resistor can be soldered in if it is found the supply is not stable.
Additionally: why does this ESR limit only exist on the output of an LDO? Why is there no such requirement for a certain level of ESR for stability on the regulator input capacitors?
Regards,
SIC
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