Current Consumption test on custom board using PPK

RE: Current Consumption test on custom board using PPK

haakonsh — Thu, 19 Apr 2018 07:29:02 GMT

2.5µA is close to what I'd expect if you have some peripherals enabled in SysON, like RTC + LFCK, WDT, etc.

RE: Current Consumption test on custom board using PPK

Rishi — Thu, 19 Apr 2018 06:04:02 GMT

I did verify the DEBUG flag as well. Also, the optimisation flags are set to default : OPT = -O3 -g3

RE: Current Consumption test on custom board using PPK

Rishi — Thu, 19 Apr 2018 06:01:31 GMT

Toyman

The default RTT was enabled.

I just disabled the NRF_LOG_ENABLE flag to disable RTT logging.

RE: Current Consumption test on custom board using PPK

haakonsh — Wed, 18 Apr 2018 13:49:22 GMT

The examples are not power optimized. You should also verify that the DEBUG flag is not set.Good job on figuring it out ^^

FYI v2.0 of the nRF Connect PPK application is out. I have not checked it out yet, but I hope it fixes some small user interface bugs.

RE: Current Consumption test on custom board using PPK

Toyman — Tue, 17 Apr 2018 15:00:08 GMT

What NRF_LOG backend did you use? UART or RTT?

RE: Current Consumption test on custom board using PPK

Rishi — Tue, 17 Apr 2018 12:28:34 GMT

Updated current draw:

System-On sleep mode = 2.5uA

Advertising = 13uA

Major current draw was due to the NRF_LOG function calls. Disabling NRF_LOG_ENABLED reduced the current drastically.

Board Support Package was disabled as well.

Advertising interval set to 4 seconds.

Additionally, DC-DC converter was enabled using

sd_power_dcdc_mode_set(1);

RE: Current Consumption test on custom board using PPK

Rishi — Tue, 17 Apr 2018 12:23:02 GMT

I have got the current down. Thank you. I shall re-open the ticket in case of further queries.

Thank you

RE: Current Consumption test on custom board using PPK

Rishi — Tue, 17 Apr 2018 05:39:41 GMT

I see.

Can you please perform a basic test using the stock ble_app_template example from SDK14.2 using nRF52832 DK and tell me the recorded current consumption using PCA63511 Power Profiler Kit?

Also, can you tell me the parameters that I can tune to reduce the current consumption in that example?

Thank you.

RE: Current Consumption test on custom board using PPK

haakonsh — Wed, 11 Apr 2018 12:26:07 GMT

I expect 131µA average for advertisements at 100ms intervals with a 27 byte payload. Check out our online power profiler at: https://devzone.nordicsemi.com/power/

You should definitely get way less than 750µA at 1600ms intervals.

RE: Current Consumption test on custom board using PPK

Rishi — Wed, 11 Apr 2018 08:41:32 GMT

Hey Hakon,

On performing various tests, I found out that the accelerometer along with Lipo charging IC is responsible for huge current draw. I should be able to reduce the current by fixing these issues.

Additionally, I am trying to understand the current consumption of nRF52-DK during advertising period. Using the ble_app_pwr_profiling example, I am measuring the current consumed in connectable mode.

I have reduced the connectable advertising period to 1 second by making following changes:

#define CONNECTABLE_ADV_INTERVAL        MSEC_TO_UNITS(200, UNIT_0_625_MS)

TO

#define CONNECTABLE_ADV_INTERVAL        MSEC_TO_UNITS(1600, UNIT_0_625_MS)

The current draw on starting the application is only 1 uA to 2 uA due to System-Off sleep mode. However, when Button 1 is pressed, the device enters connectable advertising mode. In this mode the current is approximately 750 uA during advertising bursts.

Are these values expected? Can you please explain why such huge values are expected?

Can you tell me any other area where I can make changes and bring the current further down.

Thank you.

RE: Current Consumption test on custom board using PPK

Rishi — Wed, 04 Apr 2018 09:22:08 GMT

Thanks. I shall perform the suggested tests and get back to you with my observations.

RE: Current Consumption test on custom board using PPK

haakonsh — Wed, 04 Apr 2018 09:19:52 GMT

Hey Rishi,

My first thought is that there is a short circuit somewhere, either the LIS2DH12 footprint is wrong, the LIS2DH12 is mounted wrong, or the LIS2DH12 has an internal short circuit due to damage from ESD or kinetic impact. I suggest you write a simple application that tries to communicate with the LIS2DH12. If you are unable to read the device ID given the correct commands and a verified I2C communication, then the LIS2DH12 operating out of spec in some way or another.

FYI: The nRF5 series SoCs have internal 13k pull-up/downs available on each GPIO so I believe you do not need external pull-ups on the SDA and SCL lines.

Cheers,

Håkon.

RE: Current Consumption test on custom board using PPK

Rishi — Wed, 04 Apr 2018 08:31:56 GMT

Hey Hakon,

I have isolated the problem. I have a LIS2DH12 accelerometer in my design. Assembling this accelerometer along with three by-pass capacitors (0.1 uF, 0.1 uF, 10 uF) and two pull-up resistors (10K each) for SDA and SCL lines, increases the current consumption to 7 mA.

Removing the pull-up resistors does not reduce the current consumption value either.

I am not even using or enabling the accelerometer. It is just being powered by the VDD rail. I am running ble_app_hrs example.

Any suggestions, what are the possible sources of this huge rise in current?

Thanks.

RE: Current Consumption test on custom board using PPK

Rishi — Tue, 03 Apr 2018 09:23:38 GMT

Hi Hakon,

1. I do have few other passives and ICs in my design. I have three pulls-ups (10K each), 2 for TWI and one pull-up for an IC.

2. I have not enable any internal pull-up. Do I need to get rid of external pul-ups?

3. I have been testing with stock examples without any changes.

While I was waiting for a response from your end, I have isolated the Raytac module, and current consumption is almost equal to nRF5-DK. This is observed in ble_app_hrs example which is not power optimised.

However, on running the power profiler example, during system-off sleep mode (when no button is pressed), DK consumes 60 nA current while the module consumes 530 nA current. This is inconsistent and I would like your opinion on this.

4. I am assembling my board one component at a time and performing a current consumption test in order to find out the root cause of high current consumption. Once I am done with this test, I shall share the design, if required, as a private ticket.

Thanks

RE: Current Consumption test on custom board using PPK

haakonsh — Tue, 03 Apr 2018 09:12:06 GMT

Hey Rishi,

Do you have any other circuits and devices on your custom PCB that can draw additional current?
If this is the case then you need to electrically isolate the module from the rest of your board when measuring the current.
Have you enabled any pull-ups, etc, on the module?
If this is the case then you need to disable the pull-ups/downs before measurements.
Are you running the example as provided or have you made any modification for your custom PCB?
Can you show us your schematics and/or Layout files?

Cheers,

Håkon.

RE: Current Consumption test on custom board using PPK

Rishi — Mon, 02 Apr 2018 05:02:22 GMT

Can I please have some response for this query?

Thank you.