COPCJ820 datasheet(9/32 Pages) NSC

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Functional Description (Continued)

Oscillator Circuits

EXTERNAL OSCILLATOR

CKI can be driven by an external clock signal provided it

meets the specified duty cycle rise and fall times and input

levels CKO is available as a general purpose input G7

andor Halt control

CRYSTAL OSCILLATOR

By selecting CKO as a clock output CKI and CKO can be

connected to create a crystal controlled oscillator Table I

shows the component values required for various standard

crystal values

RC OSCILLATOR

By selecting CKI as a single pin oscillator CKI can make a

RC oscillator CKO is available as a general purpose input

andor HALT control Table II shows variation in the oscilla-

tor frequencies as functions of the component (R and C)

values

TLDD11208 – 7

FIGURE 5 Clock Oscillator Configurations

TABLE I Crystal Oscillator Configuration

CKI Freq

Conditions

(kX)(MX)

(pF)

(MHz)

30 – 36

VCC e 5V

30 – 36

VCC e 5V

100

100 – 156

0455

VCC e 5V

TABLE II RC Oscillator Configuration (Part-To-Part Variation)

CK1 Freq

Instr Cycle

Conditions

(kX)

(pF)

(MHz)

(ms)

22 to 27

37 to 46

VCC e 5V

100

11 to 13

74 to 90

VCC e 5V

100

09 to 11

88 to 108

VCC e 5V

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