Application Notes TITLE: EM61 Wake-up Time Notes number : REVISION DATE REVISION VERSION AFFECTED CHIPS : : : AP-EM61-0007E-V1 5 September 2002 1.0 All EM61 Series Chips The EM61 series chips wake-up time is WDT time based. As the WDT timer utilizes internal RC mode for oscillation, fluctuation of the Vcc relative to wake-up time is apparent. Hence, when Vcc is low, wake-up time is longer. This condition is illustrated in the following chart: Wake-up time v.s.Vcc EM61002 EM61001 100 90 80 70 60 50 40 30 20 10 0 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 When working with EM61 series chip at low Vcc, do take into account the expected change in the length of wake-up time. Elan has established that the wake-up time length should be – 120 ms (max.) at Vcc=2.4V. Elan guarantees that this wake-up timing specification will be implemented to all future releases of the EM61 series chips.