BQ20Z45-R1 Charge Control SMBus Broadcasts

Hi,

I'd like to ask about the following description in SLUU387A (http://www.ti.com/lit/ug/sluu387a/sluu387a.pdf) Page29 2.5.1

"ChargingVoltage and ChargingCurrent broadcasts are sent to the Smart-Charger device address
(0x12) every 10 to 60 seconds."

Where does the variation of the interval between each broadcasts come from?

Thanks,

Go