Data Sheet

K019-CW43-DW datasheet_V1.6_15042020.doc | Shawn Xiao

6. Frequency References

6.1

External Clock Reference

The module uses a secondary low-frequency sleep clock for low-power mode timing. Either

the internal low-precision LPO or an external 32.768 kHz precision oscillator is required.

The internal LPO frequency range is approximately 33 kHz ± 30% over process, voltage,

and temperature, which is adequate for some applications. However, one trade-off caused

by this wide LPO tolerance is a small current consumption increase during power save

mode that is incurred by the need to wake up earlier to avoid missing beacons.

External LPO signal characteristics:

Parameter Specification Units

Nominal input frequency 32.768 kHz

Frequency accuracy

20

ppm

Duty cycle 30 - 70

Input signal amplitude 400 to 1800 mV, p-p

Signal type Square-wave or sine wave

Input impedance

>100k





Clock jitter (integrated

over 300Hz – 15KHz)

<10,000 ppm

External LPO signal characteristics: