Philips P89LPC903 Light Therapy Device User Manual


 
Philips Semiconductors
User’s Manual - Preliminary -
P89LPC901/902/903
WATCHDOG TIMER
2003 Dec 8 89
Periodic wakeup from Power down without an external oscillator
Without using an external oscillator source, the power consumption required in order to have a periodic wakeup is determined
by the power consumption of the internal oscillator source used to produce the wakeup.The Real-time clock running from the
internal RC oscillator can be used. The power consumption of this oscillator is approximately 300uA. Instead, if the WDT is used
to generate interrupts the current is reduced to approximately 50uA. Whenever the WDT underflows, the device will wake up.