NRF24LE1 in Register retention, timers on. Inrush current when waking up.

[r_nin]

Hello to all! I use the sleep mode PWRDWN = 0x04 and periodically wake up at WDT.With that, I see needles for the current consumption in the circuit to wake up the circuit (Fig. 1). If you use Deep Sleep mode (PWRDWN = 0x07), then there are no needles (Fig. 2). What is the reason? Thanks!

[ovrebekk]

Hi Igor

The spike you are seeing might be caused by the startup of the external 16MHz oscillator (XOSC), which could occur after wakeup from register retention (PWRDWN = 4). 

Could you try to set bit 7 in the CLKCTRL register before going to sleep?

Then the XOSC should be enabled in sleep, and the spike should not be there (just be aware that this will increase the current consumption during sleep). 

Best regards
Torbjørn

[r_nin]

Hi Torbjørn

Bit 7 in the CLKCTRL i have connected from the beginning.I connected the capacity of 22 uF to power the microcircuit. There are no more needles. Thank you for your attention to my problem. We will assume that it is solved.

[ovrebekk]

Hi Igor

Good to hear you found a solution. In general some decoupling on your supply is always a good idea, especially if you plan to run from battery

Best regards
Torbjørn