Current Consumption in deep sleep mode: when the voltage goes below 1.5V current starts peaking to 300µA.

RE: Current Consumption in deep sleep mode: when the voltage goes below 1.5V current starts peaking to 300µA.

Vidar Berg — Tue, 28 May 2024 11:16:02 GMT

Hi Naveed, please try with the system_off_pca10040.hex file I posted here: current consumption is very high during sleep off mode in nrf52832 and see if you get the same result. I can't think of anything which can explain the gradual increase in power consumption as you observing.

Regards,

Vidar

RE: Current Consumption in deep sleep mode: when the voltage goes below 1.5V current starts peaking to 300µA.

Naveed — Fri, 24 May 2024 14:31:21 GMT

Hi,

Thankyou for your response.

I understood that the device is entering into refresh mode when in ultra low power mode by observing re-charging spikes in the graph (Box1 in the graph).

You said that, when the system is off, the current consumption should be about 0.6µA, yet in my situation, as shown in the graph (Box2, to be exact), this is not the case.

I'm using a Joule scope to measure the voltage and current values accurately. I still didn't find the answer for this.

1. When the voltage hits the threshold voltage 2V current dropped to around nearly 3µA and device is put into the deep sleep mode(sd_power_system_off()). We can observe from the graph that the current reading increases progressively from 3µA to 49µA (and even up to 100µA).What might be the reason behind this device's behavior?

2. Is the device coming out of the deep sleep mode? Am I missing any configuration here before putting the device into deep sleep mode?

Can you please help me to understand what might be the reason for current consumption even if the device is put into deep sleep mode at 2V.

Regard,

Naveed

RE: Current Consumption in deep sleep mode: when the voltage goes below 1.5V current starts peaking to 300µA.

Vidar Berg — Wed, 22 May 2024 14:13:17 GMT

Hi Naveed,

The regulator will enter the auto-controlled refresh mode when in ultra low power mode ( Auto controlled refresh mode ), and I suspect you may be observing re-charging spikes. The current consumption should be around 0.6 uA in system OFF, which is well below what you are currently measuring. Is it possible that the sample rate in your measurement setup is too low to properly measure the spikes resulting in aliasing? The system OFF current should be measurable with a multimeter.

RE: Current Consumption in deep sleep mode: when the voltage goes below 1.5V current starts peaking to 300µA.

Naveed — Wed, 22 May 2024 13:25:53 GMT

Hi,

Thankyou for your quick response.

The data sheet states that a nominal voltage of 3V and a range of Min=1.7V to Max=3.6V are the recommended operating voltages.

Observed current readings are attached in the image below. For the defined threshold voltage VPOF=2V.

1. When the voltage is at 2.4V, I can see the constant oscillation here (from low 4µA to high 18µA). What could be causing the device to act in this way?

2. When the voltage hits the threshold voltage 2V current dropped to around nearly 3µA and device is put into the deep sleep mode(sd_power_system_off()). We can observe from the graph that the current reading increases progressively from 3µA to 49µA (and even up to 100µA).What might be the reason behind this device's behavior?

3. Is the device coming out of the deep sleep mode? Am I missing any configuration here before putting the device into deep sleep mode?

Can you please help me to understand what might be the reason for current consumption even if the device is put into deep sleep mode at 2V and the constant oscillations at 2.4V in the operating condition.

Regards,

Naveed

RE: Current Consumption in deep sleep mode: when the voltage goes below 1.5V current starts peaking to 300µA.

Vidar Berg — Tue, 21 May 2024 06:58:43 GMT

The supply voltage must be 1.7V or higher to ensure normal operation, see Recommended operating conditions.

RE: Current Consumption in deep sleep mode: when the voltage goes below 1.5V current starts peaking to 300µA.

Turbo J — Mon, 20 May 2024 13:24:58 GMT

At some point you will trigger a low voltage POR. Its not possible to operate the µC properly when voltage drops too low - back to the drawing board, you probably need to change the schematic.

See also V_BOR,OFF in the POWER section with electrical specs.