# STM32F103C8T6 Standby mode consumption too high

I am facing a realy strange problem while trying to put my "bluepill" with stm32f103c8t6 onboard into a standby mode. The consumption in standby mode is .8mA (what is 40 times higher then its supposed to be) on first board (Board A) and .02mA (what is 10 times higher) on second board (Board B). I spent 2 days already reading datasheet and reference manual and cannot get below .8mA.

(Board A) was modifyed by removing the on board voltage regulator and 2 LEDs. (Board B) has only the uC, 2 resistors (100k R3, R4).

The code I use is the following:

RCC->APB1ENR |= RCC_APB1ENR_PWREN; ADC1->CR2 &= ~(1UL << 0); ADC2->CR2 &= ~(1UL << 0); SCB->SCR |= SCB_SCR_SLEEPDEEP_Msk; PWR->CR |= PWR_CR_PDDS; PWR->CR |= PWR_CR_CWUF; PWR->CSR |= PWR_CSR_EWUP; __WFI();

I am running at 8MHz (probably not so important in this case). I have already tried to put all pins into analog input mode (to disconnect the internal schmitt trigger).

• Wait, is the whole bluepill consumption 0.8mA while the expected consumption of the stm32f103c8t6 should be 1/40 th of that? Maybe it is some circuit in the bluepill that is using all that quiescent current and not really the stm32f103c8t6. – jDAQ Apr 12 at 16:50
• Ok I see you modified the bluepill board, are there any other non essential circuitry left? – jDAQ Apr 12 at 16:51
• No, the board only has some resistors, caps and two oscilators on it. Osciloscope says that the oscilators are quiet. – Markiyan Pyekh Apr 12 at 16:54
• A actually have another board, that I did not mentioned in my post. This second board has 3 components on it: uC and two 100k resistors(R3,R4) for BOOT. Its consuming .02mA(20uA, what is 10 times more than I expect). – Markiyan Pyekh Apr 12 at 16:56
• Please, update the post itself with the newer/correct information. – jDAQ Apr 12 at 17:09