Using nPM1300 with fixed DC input (no USB)

[chris_h]

Hi,

I'm looking to use the nPM1300 with a fixed 5V DC input (no USB). I still want to use the rest of the nPM1300 features together with an MCU, including lithium battery charging, fuel gauging, buck regulators, but my circuit will be powered off a DC input instead of the traditional USB port.  The intention is to connect the nPM1300 Vbus (pins B1,B2 on WLCSP) to my 5V DC power source. with a common ground

Can you please assist with a few questions about this?

1. On my circuit, should I pull the CC1 line to 5V with a 5.1k resistor and pull the CC2 to ground with a 5.1k resistor, to make the PMIC think its working with a USB host / charger.
2. Or does the nPM1300 not care if it is communicating with a USB host?  Is there additional negotiation beyond the pull-ups and pull-downs on the CC lines, or additional nPM1300 register configurations I need to implement? 

Thanks in advance.

Chris

[Tomi Koskela]

Hello,

1. You can leave then floating

2. No communication is needed between nPM1300 and the USB host. The CC lines can be used to detect the USB host max current capability, but even then it is not automatic, you can read the detected value in the register and SoC can set the VBUSINLIM accordingly through TWI. So you can just set the VBUS current limit to the desired value with TWI write when the 5V adapter is plugged. Note the default is 100mA, so that is the maximum you can draw from the 5V supply with the default setting. You can program it up to 1500mA.

[chris_h]

Thank you, that perfectly answers my question!