nPM1300 Maximum discharge current limit

[AvihayZ]

Hello,

We are using nPM1300 in our project.

I would like to configure it to the maximum possible discharge current limit, as there are inrush currents in the board.

I have several questions:

1. In the PS it is mentioned that there are two discharge current settings - Low and High:
   
   While in Zephyr's driver (nordic,npm1300-charger.yaml) it is mentioned that the available range is 270 mA to 1340 mA in 3.23 mA steps:
   
   What is true?
   
   
2. When setting the dischg-limit-microamp to 1340000 (the maximum value according to the driver), the registers values are:
   BCHGISETDISCHARGEMSB = 207
   BCHGISETDISCHARGELSB = 0
   While according to the datasheet it should be BCHGISETDISCHARGELSB = 1.
   
   What value I should set to dischg-limit-microamp in order to achieve the maximum possible discharge current limit?

Thank you,

Avihay

[Jared]

Hi,

Only the 2 values listed in the product specification is officially supported. I agree that we need to update the yaml file to make that more clear. 

When setting the dischg-limit-microamp to 1340000 (the maximum value according to the driver), the registers values are:
BCHGISETDISCHARGEMSB = 207
BCHGISETDISCHARGELSB = 0
While according to the datasheet it should be BCHGISETDISCHARGELSB = 1.

What value I should set to dischg-limit-microamp in order to achieve the maximum possible discharge current limit?

What nRF Connect SDK Tag are you using? 1340000 Should be correct. 

Can you show me the dts/overlay where you apply this? 

regards
Jared 

[AvihayZ]

Hi Jared,

We are using tag v3.6.99-ncs2.

The charger configuration in the dtsi file is as below:

npm1300_charger: charger {
            compatible = "nordic,npm1300-charger";
            status = "okay";
            term-microvolt = <4100000>;
            term-warm-microvolt = <4000000>;
            current-microamp = <130000>;
            dischg-limit-microamp = <1340000>;
            vbus-limit-microamp = <500000>;
            thermistor-ohms = <10000>;
            thermistor-beta = <3435>;
            charging-enable;
        };

[Hung Bui]

Hi Avihay, 
Jared is away this week. I will try to help in the mean time. 
I think you should set the dischg-limit-microamp to 1000000. What's the value of BCHGISETDISCHARGELSB when you set the dischg-limit-microamp to 1000000 ? 

[AvihayZ]

Hello,

Thank you for the update.

When dischg-limit-microamp is set to 1000000, the values are:

BCHGISETDISCHARGEMSB = 154
BCHGISETDISCHARGELSB = 1

[Hung Bui]

Hi Avihay, 
I'm sorry for the delayed answer. I got the response from my team that the Zephyr driver is our of date and should be updated. But for now you still need to use the maximum value (1340) This should ensure that the discharge limit stays above 1A for all device variations. The zephyr driver will be updated to reflect the most recent PS, but this will take some time to trickle down to NCS.