nPM1300 normal mode quiescent current

[kyozc]

Hi Nordic,

According to the datasheet the nPM1300 normal mode quiescent current is about 800nA.

We can achieve that use nPM1300-EK when first power up.

But when we connect to pc use nPM PowerUP and disconnect. The  nPM1300-EK quiescent current will go up to 1mA.

And when we connect to nrf52840-DK And run npm1300_fuel_gauge example and disconnect. The nPM1300-EK quiescent current will go up to 3.7mA.

Is there any way to make the quiescent current below 1uA  without enter SHIP/HIBERNATE Mode ?

Thanks

[Andy Sinclair]

Hello.

The fuel gauge sample uses a shield overlay (npm1300_ek.overlay), which includes example configuration for GPIO control of enable, retention and PWM modes.

You can add the following to your project overlay (n2f52840dk_nrf52840.overlay) to disable the GPIO control behaviour, and ensure that all these modes are only controlled by software.

&npm1300_ek_buck2 {
	/delete-property/ enable-gpios;
	/delete-property/ retention-gpios;
	/delete-property/ pwm-gpios;
};

&npm1300_ek_ldo1 {
	/delete-property/ enable-gpios;
};

&npm1300_ek_ldo2 {
	/delete-property/ enable-gpios;
};

Andy

[kyozc]

Hi Andy,

We add the overlay to the project and the quiescent current go down to 1.0mA.

Is there any other config change we can make the quiescent current below 1uA?

Thanks

Best regards,
Chen

[Andy Sinclair]

Hi Chen.

Do you see 1mA current all the time, or only after you disconnect?

The EK software used for PowerUp configure a GPIO as an interrupt between the nPM1300 and the SOC.  This output will use additional current until the interrupt is serviced.

If you disconnect the SOC once this is enabled, the interrupt won't be cleared and you will see additional current.

[kyozc]

Hi Andy,

When use EK&PC , we see 1mA after disconnect from PC , when use EK&NRF52840-DK We see 1mA current all the time.

[Andy Sinclair]

Hi.

When it is in this state, could you do the following test to check if it is the software configuration that is causing the issue?

1. Hold the SHPHLD/RESET button on the EK for > 10 seconds to reset the PMIC.
    The current should drop.

2.  Press the reset button on the DK.
     Does the current rise to 1mA?

A couple of additional questions:
* How are you powering VBAT? (Battery / PPK / power supply)
* How are you measuring the current?

Thanks
Andy

[kyozc]

Hi Andy.

1. Hold the SHPHLD/RESET button on the EK for > 10 seconds to reset the PMIC.
    The current should drop.

Yes the current drop to <1uA

2.  Press the reset button on the DK.
     Does the current rise to 1mA?

Yes the current rise to 1mA

A couple of additional questions:
* How are you powering VBAT? (Battery / PPK / power supply)

Battery(Li-Po 320mAh)

* How are you measuring the current?

Digital Multimeter(DM3068) in series

Thanks
Chen

[Andy Sinclair]

Thanks Chen.

When running the fuel gauge sample, the current will rise to 1mA when the SoC is communicating with the PMIC via the TWI interface.

This will be a short pulse (approx 4ms) once a second.

I'm not sure how a meter will display this, so could you try disabling this communication in main.c:

	while (1) {
		// fuel_gauge_update(charger);
		k_msleep(SLEEP_TIME_MS);
	}

Thanks

Andy