Excessively high output error (4%) with NPM1100

[peterqu94305]

Hello,

We have designed a product with NPM1100.  With the NPM1100 set to output voltage of 3.0, we have measured the output across multiple devices to be in the 3.1 to 3.15V range.  This is an approximately 4% error on the output. 

Our questions are:

1. What is the expected output accuracy of NPM1100?
2. What is the expected accuracy of the charging termination voltage?  If the charging termination voltage has the same level of large error, then we have genuine concern about whether using NPM1100 can lead to potential safety hazard with lithium-ion battery.

Our configuration is as follows.

1. Micro USB input
2. Rechargeable lithium ion 80mAH
3. Output configured to 3.0V

Thank you,

Peter

[peterqu94305]

Hello Sigurd,

Thank you for the reply.  For our use case, -2 to +8% error is acceptable.  So I think this issue can be closed since the NPM1100 is operate within the specification.

That being said, most of the competing buck regulators or PMIC have error of +/- 2%.  We are just surprised (unpleasantly) that the Nordic PMIC has such as a large output error when it is priced at same level as the TI PMIC and a significantly premium compared to PMIC from Asia.  Its not a good feeling to pay for a premium price and got a mediocre product.

Thank you,
Peter

[Sigurd Hellesvik]

Hi

Another note on the output error.
It is normal for PMICs to have +4% typically in no load condition. The nPM1100 specified -2/+8% and because of that we trim value a bit high with no load condition to cover all cases.

Regards,
Sigurd Hellesvik