External Circuit Design

AN2317 - Application

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1.6

Clock Generation

All of the STPM01 internal timing is based on the CLKOUT oscillation signal. This signal can

be generated in three different ways:

●

RC (see

Figure 13)

This oscillator mode can be selected using the RC configuration bit. If RC = 1, then the

STPM01 will run using the RC oscillator. A resistor connected between CLKIN and

Ground will set the RC current.

Note:

For 4MHz operation, the suggested settling resistor is 12k.

●

Quartz (see

Figure 14)

The oscillator will work with an external crystal.

Figure 13.

Internal RC Recommended Connections

Figure 14.

Quartz Recommended Connections

VSS

12k

CLKIN CLKOUT

AI12915

VSS

1M

4194MHz

15pF

15pF

CLKIN CLKOUT

AI12916