LPC804 Power consumption

[thinkking1985]

According to the LPC804 Datasheet , I test  the power dowm mode and I found the power consumption too high.

2:demo code:

for (i = 0; i < 30; i++)//disable pull-up
{
modefunc = (IOCON->PIO[i] & (~IOCON_PIO_MODE_MASK)) [UNK] IOCON_PIO_MODE(0UL);
IOCON_PinMuxSet(IOCON, (uint8_t)i, modefunc);
}
/*Set the pin to output and output low*/
gpioPinConfigStruct.pinDirection = kGPIO_DigitalOutput;
gpioPinConfigStruct.outputLogic =0UL;
for (i = 0; i <= 30; i++)
{ }
GPIO_PinInit(GPIO, 0UL, i, &gpioPinConfigStruct);
}

3:test result

1）：disable pull-up and set the pin to output and output low:1323uA

2) enable pull-down and and set the pin to output and output low：1338uA

The test results are inconsistent with the datasheet .

Can you provide detailed test documents for verification?

Thank you.

[diego_charles]

Hi @thinkking1985 

I hope you are doing well!

Ok, another thing to look in your setup is ensuring that the BOD is disabled, to decrease power consumption.

To perform  current measurements , we recommend to refer to the  PMU_Modes example from the LPC804 Code bundle (available for MCUXpresso , KEIL and IAR IDEs) In the README.txt of the example you will find a note  indicating typical current consumption  measurements, which are close to the datasheet specs.

Power mode        Typical VDD_main current running from 12 MHz FRO
==================================================================
while(1)          1.4   mA
Sleep             0.58  mA
Deep sleep        124.0 uA
Power down        6.00  uA
Deep power down   0.16  uA

Are you using a custom board? Or are you able to test with one of our demo boards?

I hope this could help you. 

Diego.

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[thinkking1985]

Hi Diego

1: I tested code is attached. Can you help me test it? Thank you.

2:Project demo:

SDK_2.9.0_LPCXpresso804_20210822\boards\lpcxpresso804\demo_apps\power_mode_switch_lpc\mdk

[thinkking1985]

Hi Diego

the customer' board as follow,the board is the smallest system and has no other functions.Use PMU_ The mode demo code can't get the above result, Thank you.
tks a lot.

My question is according to the LPC804 datasheet, set the IO port to the output mode. disable the pull-up and output is low. Why does the power consumption get high? But I set the IO port to the input mode t and enable pull-up. The power consumption data is very low.
Thank you.

[diego_charles]

Hi @thinkking1985 

I hope you are doing fine! I have been doing tests with my LPCXpresso812

Test 1  Set  I/O to output low and   disable the pull-ups: 

  Current consumption increased, as you mentioned,  from 1102 uA to  1600 uA approximately

Test 2 Set  I/O to output high  and  disable the pull-ups.

 Current consumption maintained , being less or equal to 1102 uA, which is the standard current consumption after reset for my LPC812 and the example that I am running.

While in power down in 46 uA, but noticed , but  my LPC812 example was not too optimized.

According to the example PMU  Modes that I recommended you earlier :

and the default SDK lpcxpresso804_power_mode_switch_lpc example

In conclusion to be able to get closer to the DS current consumption we can  set GPIOs  output to high and disable internal pull-ups. 

I will check with our AE  team this statement in the LPC804 DS, which lead to confusion, as make us think that to get closer measurements  we need to output pins to low. 

I think that the higher consumption with the  pins set/driven to low is because  internal I/O construction path. 

I hope this could help you , and thank you for your patience. 

Diego.