ST72681

Electrical characteristics

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7.5

Clock and timing characteristics

7.5.1

General timings

7.5.2

Crystal oscillator

The ST72681 internal clock is supplied from a crystal oscillator. All the information given in

this paragraph are based on characterization results with specified typical external

components. In the application the load capacitors have to be placed as close as possible to

the oscillator pins in order to minimize output distortion and start-up stabilization time. Refer

to the crystal manufacturer for more details (frequency, package, accuracy...).

Figure 7.

Typical application with a crystal oscillator

1.

crystal oscillator manufacturer for more details.

Table 13.

General timing characteristics

Symbol

Parameter

Conditions

Min.

1.

Data based on typical application software.

Max.

Unit

23

12

133

200

800

ns

2.

Time measured between interrupt event and interrupt vector fetch.

required to finish executing the current instruction.

10

22

0.666

1.466

µs

Table 14.

Crystal oscillator characteristics

Symbol

Parameter

Conditions

Min.

Typ.

Max.

Unit

Oscillator frequency

12

MHz

Total crystal oscillator accuracy abs. value + temp + aging

±60

ppm

1.

manufacturer for more details.

45

50

55

%

Table 15.

Supplier

Typical crystal oscillator

NDK

AT51 or AT41

16

560

OSCOUT

OSCIN

Device

CRYSTAL

(1)