Datasheet

Functional description ST7538Q
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Figure 17. PLI startup timing diagram
5.9 Crystal oscillator
ST7538Q integrates a inverter driver circuit to realize a 16MHz crystal oscillator.
This circuit is able to drive a maximum load capacitance of 16pF with typical quartz ESR of
40Ω.
If the internal driver circuit is used, only one external crystal quartz and two external load
capacitors (C
1
and C
2
) are needed to realize the oscillator function (Figure 18).
Figure 18. Typical crystal configuration if internal crystal driver circuit is used
If an external oscillator is used, XOUT must be disconnected, while XIN must satisfies the
specifications given in Table 4 (see Figure 19).
T
ST
4V
0V
T
ALC
T
RXTX
RX/TX
ATOP2
STEP NUMBER 16 17 18 31
D03IN1408
XOUT XIN
D03IN1425A
C 1 C 2