NPM1100 Charge expected behaviour questions

[i_4556]

Hello, and thank you for your time. We have designed an NPM1100 into a product, and are unclear on if the behaviour of the charge pin is correct (nor indeed what exactly is the expected behaviour).

Our expectation is the following: when charging is actively occurring, thats to say current is flowing into the battery, the charge pin should be active (low). In all other cases, the charge pin should be inactive (high).

We have noticed the charge pin low when there is no Vusb and our device is operating off the battery. Is this correct, that the charge pin is active when charging could potentially occur (battery voltage within the charge range) even if it is not actually occurring?

Thank you!

[Susheel Nuguru]

The behavior of the CHG (charge) pin on the nPM1100 PMIC is as follows: When the nPM1100 PMIC is charging the battery, the CHG pin is pulled low. This pin is connected to General-Purpose Input/Output (GPIO) P1.00. The CHG pin and the ERR (error) pin sink 5 mA of current when active and are high impedance when disabled. This is suitable for driving LEDs or connecting to host GPIOs in a weak pull-up configuration. The charging indication pin, CHG, is active while the battery is charging which is mentioned here

However, the CHG pin should not be active (low) when there is no Vusb and the device is operating off the battery. If you are observing this behavior, it might be due to some other factors or conditions. It would be beneficial to check the charger error conditions as well as mentioned here.

[i_4556]

Sorry to bump you but we really need an answer soon, thanks for your time and understanding