An external MCU occasionally sends data to the nRF54L05 over I2C. Between transfers, the nRF54L05 should sleep and wake when addressed, without a separate wake pin.
What is the total standby current at 3 V with TWIS enabled, radio off, and no bus traffic? Does TWIS keep the HF clock running? Any measurements or required low-power settings?
Hello,
It won’t keep the HF clock running, but it will still increase the floor current. I measure 18 uA in sleep (System ON) at 3 V with TWIS enabled on my desk with the nRF54l15DK emulating the nrf54l05 and the test sample attached below (built with NCS v3.4.1).
Best regards,
Vidar
PPK2 plot:
EDIT: The nRF15L05 has the TWIS30 instance in the low power domain. Switching to that instance gave significantly lower power consumption in System ON idle:
To test this you can swap out the content of the board devictree overlay with this:
/*
* TWIS30 (LP domain) must use port P0. SCL must be on a clock pin: P0.04 (DK Button 3).
* SDA: P0.02 (DK VCOM0 RTS, disconnect VCOM0 in Board Configurator).
*/
&pinctrl {
twis30_default: twis30_default {
group1 {
psels = <NRF_PSEL(TWIS_SDA, 0, 2)>,
<NRF_PSEL(TWIS_SCL, 0, 4)>;
bias-pull-up;
};
};
twis30_sleep: twis30_sleep {
group1 {
psels = <NRF_PSEL(TWIS_SDA, 0, 2)>,
<NRF_PSEL(TWIS_SCL, 0, 4)>;
low-power-enable;
};
};
};
&i2c30 {
compatible = "nordic,nrf-twis";
pinctrl-0 = <&twis30_default>;
pinctrl-1 = <&twis30_sleep>;
pinctrl-names = "default", "sleep";
status = "okay";
};
And if you are using the nordic DK, disconnect the UART lines from the interface MCU so they can be assigned to the TWIS instead.
