LPC MicrocontrollersのトピックRe: LPC804 Power consumption

LPC804 Power consumption

thinkking1985 — Wed, 01 Sep 2021 15:26:23 GMT

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.

Re: LPC804 Power consumption

diego_charles — Mon, 06 Sep 2021 15:52:31 GMT

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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Re: LPC804 Power consumption

thinkking1985 — Tue, 07 Sep 2021 00:47:48 GMT

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.

Re: LPC804 Power consumption

thinkking1985 — Tue, 07 Sep 2021 01:15:49 GMT

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

Re: LPC804 Power consumption

diego_charles — Fri, 17 Sep 2021 21:56:52 GMT

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.