nPM1300 - The BUCK output voltage is on average 50 mV below the configured value in Hysteretic mode

[Mato Lovrenovic]

Hi all,

We are using the nPM1300 build version QEAA-C00 in our design and have encountered an issue with the voltage levels of the buck converters.

The output voltages are set to 1.8V using VSET1 and VSET2 resistors, but at light loads with auto mode enabled, the average output voltage is around 1.75V.

The errata [34] BUCK: BUCK output voltage accuracy is outside of specification in Hysteretic mode (nordicsemi.com), which seems to describe a similar problem.

Could you please advise on a solution for this issue? Would switching to forced PWM mode help?

Additionally, will the hysteretic mode issue be addressed in the next silicon revision?

Thank you in advance for your assistance.

Best regards,

Mato

[dacr]

Hi Mato,

Yes, forcing PWM mode will help with the accuracy of the output voltage level, however it will increase current consumption and hence drastically reduce efficiency. The next silicon revision will address this issue.

All the best,

Dan

[Mato Lovrenovic]

Hi Dan,

Do you know when the next silicon revision is expected to be released?

Best regards,
Mato

[dacr]

I will forward your question, and get back to you.