Deep power down mode LPC802 supply current

[eva]

I am using a LPC802 in deep power down mode, the current should be 0.15uA, but I have a 13,8uA current consumption.

Following the example "power_mode_switch_lpc.c":

I configure the wakeup pin:

POWER_DeepPowerDownWakeupSourceSelect(kPmu_Dpd_En_Pio0_17);

where:

static inline void POWER_DeepPowerDownWakeupSourceSelect(uint32_t wakeup_pin)
{
PMU->WUENAREG |= wakeup_pin;
}

and to enter deep power down mode call the function:

POWER_EnterDeepPowerDownMode();

where:

void POWER_EnterDeepPowerDownMode(void)
{
uint32_t pmsk;

pmsk = __get_PRIMASK();
__disable_irq();

/* make sure NODPD is cleared */
PMU->PCON = (PMU->PCON & (~(PMU_PCON_PM_MASK | PMU_PCON_NODPD_MASK))) | PMU_PCON_PM(kPmu_Deep_PowerDown);

/* enable Deepsleep mode in the ARM-CORTEX M0+ SCR register */
SCB->SCR |= SCB_SCR_SLEEPDEEP_Msk;

/*clear wake up pin status flag*/
PMU->WUSRCREG |= PMU_WUSRCREG_WUSRCREG_MASK;

/* Enter powerdown mode */
__WFI();

/* disable Deepsleep mode in the ARM-CORTEX M0+ SCR register */
SCB->SCR &= ~SCB_SCR_SLEEPDEEP_Msk;
__set_PRIMASK(pmsk);
}

All the pins are without external connections, except wakeup pin, where I have an external pullup

[Pavel_Hernandez]

Hello, I suggest removing the 56k RPUL. To test this issue

Best regards,
Pavel

[eva]

Hello, if I remove 56k pullup, current consumption increases up to 45 uA

[Pavel_Hernandez]

Hello, I have checked the code, suggest mode the below configuration to test this issue.

Do not disable the GPIO0 clock,

Because I don't have your board, it's limited for me to check this issue.

Best regards,
Pavel

[Pavel_Hernandez]

Hello, let me get more information.

Best regards,
Pavel

[eva]

Hello Pavel,

I am using a custom board, all the pins are disconnected except the wake up pin (it has an external pullup resistor of 56komhs), and VDD is 3v3.

I am using a polimeter in series with VDD to measure the current. If I write value 0x02 in PMU->PCON PM bits(power down mode) instead of value 0x03 (deep power down mode), I measure a current of 6uA (same as datasheet).

The temperature is 22ºC.

Regarding pins I tryed floating pins and also with all pins configured as GPIO outputs driven LOW and pull-up resistors disabled, but result is the same.  User manual says:"All functional pins are tri-stated in deep power-down mode except for the WAKEUP pin".

The debugger is disconnected from the board.

Best regards,

Eva

[Pavel_Hernandez]

Hello, my name is Pavel, and I will be supporting your case, let me get into your case when I have more information I will contact you.

Best regards,
Pavel

[eva]

Hello Pavel, any news regarding this issue? 6uA is too much for my application, I would need a current consuption below 1uA. 

Thank you in advance.

[eva]

Thank you Pavel.

If I write value 0x02 in PMU->PCON PM bits using the same function, the current consumption goes to 6,5uA (power down mode)

With 0x03 value (deep power down mode), consumption is 13,8uA

[Pavel_Hernandez]

Hello, sorry for the late response, I´m following your case, I have some questions about it.

Could you let me know if you are using a EVK or custom board?
Could you share a schematic about how you are made the measure?

The table on it has this note.
[1] Typical ratings are not guaranteed. The values listed are for room temperature (25 C), VDD = 3.3 V.

What kind of temperature do you have?
See the Fig 19. Deep power-down mode.

Did you put floating the unused pins?
[3] IDD measurements were performed with all pins configured as GPIO outputs driven LOW and pull-up resistors disabled. 

In addition, please make sure you DISCONNECT the board with IDE debugger when measure. 

Best regards,
Pavel

[eva]

Hello Pavel,

I am using a custom board, all the pins are disconnected except the wake up pin (it has an external pullup resistor of 56komhs), and VDD is 3v3.

I am using a polimeter in series with VDD to measure the current. If I write value 0x02 in PMU->PCON PM bits(power down mode) instead of value 0x03 (deep power down mode), I measure a current of 6uA (same as datasheet).

The temperature is 22ºC.

Regarding pins I tryed floating pins and also with all pins configured as GPIO outputs driven LOW and pull-up resistors disabled, but result is the same.  User manual says:"All functional pins are tri-stated in deep power-down mode except for the WAKEUP pin".

The debugger is disconnected from the board.

Best regards,

Eva