ATWILC1000B-MUT [DATASHEET]

Atmel-42491B-ATWILC1000B-MUT_Datasheet_03/2016

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5.2

Low-Power Oscillator

ATWILC1000B has an internally-generated 32kHz clock to provide timing information for various sleep

functions. Alternatively, ATWILC1000B allows for an external 32kHz clock to be used for this purpose, which is

provided through Pin 24 (RTC_CLK). Software selects whether the internal clock or external clock is used.

The internal low-power clock is ring-oscillator based and has accuracy within 10,000ppm. When using the

internal low-power clock, the advance wakeup time in beacon monitoring mode has to be increased by about

1% of the sleep time to compensate for the oscillator inaccuracy. For example, for the DTIM interval value of 1,

wakeup time has to be increased by 1ms.

For any application targeting very low power consumption, an external 32kHz RTC clock should be used.