current consumption due to SPI FLASH on DA14531 module

Hi JackDialog,

Thank you for your online forum question and your interest in our DA14531 products.

You can find information on DA14531 module's power consumption in the datasheet

https://www.renesas.com/eu/en/document/dst/da14531-module-datasheet?language=en&r=1601921 

pages 10, 11 on Device Characteristics. As can be seen in the table 



The supply current should be between 1.7->2.1 uA when in extended sleep mode.

The module's flash can be powered down via software, same for the USB kit's flash. You can use the spi_flash_power_down() api for this purpose. You might also find the following section of the peripheral drivers tutorial on spi flash

http://lpccs-docs.renesas.com/da145xx_tutorial_sdk6_peripherals/da14531_spi_flash.html# 

useful.

Best regards,
AA_Renesas

Thank You fro fast response.

In iBeacon example I see there is flash power down

void user_app_on_init(void)
{
    /* If we have booted from flash then it will still be in active mode, power down to 
         reduce current consumption. */
    (void)spi_flash_power_down();	
    
    #if defined (__DA14531__) && defined (TX_POWER_2d5Bm)
            /* Set output power to maximum value (+2.5dBm) */
            rf_pa_pwr_set(RF_TX_PWR_LVL_PLUS_2d5);
    #endif

    default_app_on_init();
}

I measured currents one more time and have:

9uA with connected and powered down FLASH (earlier I saw 24uA due to connecting FLASH ON-THE-FLY while program running, now changed DIP's before powering and have 9uA)

1,2uA with disconnected FLASH (disabling DIP's after boot).

So, if DA14531 module has SPI FLASH connected in the same manner as USB kit, how can I obtain near 2uA? Is it possible?

Hi JackDialog,

Could you please navigate to file spi_flash.c and make the following modification to function spi_flash_power_down

int8_t spi_flash_power_down(void)
{
    SPI_FLASH_ENABLE_POWER_PIN();

    // Check if SPI Flash is ready
    int8_t status = spi_flash_is_busy();
	status = spi_flash_is_busy();
    if (status != SPI_FLASH_ERR_OK)
    {
        return status;							
    }
		
    spi_set_bitmode(SPI_MODE_8BIT);
    spi_transaction(SPI_FLASH_OP_DP);

    return SPI_FLASH_ERR_OK;
}

rebuild the ibeacon project and measure the current consumption again (with enabled DIPs for the flash)?

Please let us know with your results.

Best regards,
AA_Renesas

Thank You for response.

There is no difference in current consumption after  suggested change.

It is only added one line, correct?:

status = spi_flash_is_busy();

Other code is the same in this function.

I found also in code that there is reference to UM-B-151 application note:

6. Secondary bootloader project — Extending flash support for DA14531 (dialog-semiconductor.com)

where i found:

This is primary intended for minimizing inrusch current in boost mode, but there is that: "Apart from the boost mode the same configuration can be used in buck mode as well. In that case the GPIO pin can be used to shut down the flash completely."

So, i suppose that this is the only way to reduce current?

Also checked, that spi_flash_power_down() function works (makes difference). There is 9uA with this function enabled and 24uA without.

Hi JackDialog,

I replicating your current measurement setup with a usb kit. I am running the ibeacon example with an advertising interval of 5s in order to get extended sleep current measurements (setting ADV_INTERVAL_ms to 5000 in user_app.c). When not using the spi_flash_power_down command with DIP switches on I am getting a power consumption of ~9-10uA. When using the command I am getting the expected ~1.3uA power consumption. 

Would it be possible for you to share your project so that we can try to replicate your current measurements in our setup? This could held us further pinpoint the issue.

Best regards,
AA_Renesas

sure, can I send You private?

So, since i have 1,2uA with DIPS off it seems to be a hardware issue. Did You remove R50 before measuring current on USB devkit?

Hi JackDialog,

You can raise a ticket on "Contact Support" and  share your project in private

https://en-support.renesas.com/dashboard

JackDialog said:

Did You remove R50 before measuring current on USB devkit?

Yes, I did remove the R50 resistor prior to measuring currents on the devkit.

Best regards, 
AA_Renesas

Hi JackDialog,

You can raise a ticket on "Contact Support" and  share your project in private

https://en-support.renesas.com/dashboard

JackDialog said:

Did You remove R50 before measuring current on USB devkit?

Yes, I did remove the R50 resistor prior to measuring currents on the devkit.

Best regards, 
AA_Renesas

Thank You, ticke raised: 352685.

Not sure if source files enough, but whole project was rejected due to size exceeds limit 

So, the solution is:

1. Identify what is Your FLASH device that You are using (Macronix, Adesto or other), e.g  run a read JEDEC id command. Check in datasheet what power down modes are supported, what currents are characterised and what commands are needed for Your device.

2. Use proper sleep command:

spi_flash_power_down(), or

spi_flash_ultra_deep_power_down()

Place it usually in  user_app_on_init() function.

3. Some devices with Ultra Deep Power Down mode needs longer time to wake up so secondary bootloader is needed sometimes. Consider this:
AN-B-088: DA145xx Flash Selector Guide (renesas.com)

Hi JackDialog,

Thank you for your feedback and contribution. I marked your answer as verified so that it can be visible as a solution to other forum users.

Best regards,
AA_Renesas