FS9721_LP1

Rev. 2.0

23/41

14.7

Activated Reset Circuit

RST

FS9721_LP1

VDD

C4

10nF

S12

RESET

R5

100k

Diagram 16

Reset Circuit

14.8 Crystal Oscillator Circuit

U1

XOUT

XIN

CX1

CX2

FS9721_LP1

R1

Diagram 17

Crystal Oscillator Circuit

In the diagram, R1 provides the statical working point for the revisor; CX2 is for tiny adjustment of frequency;

CX1 is temperature compensation. In less requirements situation, CX1 and CX2 can be unused.