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STM8S power (current) consumtion problem

MBern.5
Associate

I'm developing some applications with STM8S003K3 now (battery-used product). The problem is that, I cannot make the MCU consume just 4.5 micro-ampere order current in the halt mode as in the datasheet described.

I use the Eval-Board "STM8SVLDISCOVERY" and i removed the jumper JP1, R12 and R19 to be ensure that other consumers are connected with the VDD net.

Are there other hidden consumers? Or which commands are necessary to switch off all Clocks etc. and go correctly in the halt mode?

2 REPLIES 2
WilkoL
Senior

The STM8S003 uses 4.5uA only when it is in Halt Mode. The only way to wake it from that mode is with an External interrupt (or reset). As soon as you have anything running on the STM8S003 such as the LSE (for AWU) current consumption goes up.

Also check for GPIO with resistive loads and floating GPIO. Unused GPIO are best configured as Input with Pullup.

WilkoL
Senior

With AWU active current consumption goes up to 9 uA. So that's 5uA extra that the LSI probably uses.

Make sure that you have :

CLK_SlowActiveHaltWakeUpCmd(ENABLE);
FLASH_SetLowPowerMode(FLASH_LPMODE_POWERDOWN);

when you are using the AWU, if you forget those, current goes up to more than 150uA !

About any unused GPIO, as I said configure them as input with pull up, and remember that the GPIO for I2C do not have an internal pullup, so add a 10k resistor to Vdd.