CLOCK SYSTEM (Cont’d)
Figure 9. OSG Filtering Principle
(1)
(2)
(3)
(4)
(1) Maximum Frequency for the device to work correctly
(2) Actual Quartz Crystal Frequency at OSCin pin
(3) Noise from OSCin
(4) Resulting Internal Frequency
Figure 10. OSG Emergency Oscillator Principle
Main
Oscillator
Emergency
Oscillator
Internal
Frequency
ST62T28C/E28C
VR001932
VR001933
17/84
17