PROGRAMMABLE MODES

Several modes of operation can be programmed with bits R16–R20 including the phase detector polarity, charge pump

TRI-STATE and the output of the F

grammable modes are shown in

Table 1. Truth table for the programmable modes and F

Table 3.

TABLE 1. Programmable Modes

C1

C2

R16

R17

R18

R19

R20

0

0

IF Phase

IF I

CPo

IF D

o

IF LD

IF F

o

Detector Polarity

TRI-STATE

0

1

RF Phase

RF I

CPo

RF D

o

RF LD

RF F

o

Detector Polarity

TRI-STATE

C1

C2

N19

N20

1

0

IF Prescaler

Pwdn IF

1

1

RF Prescaler

Pwdn RF

TABLE 2. Mode Select Truth Table

Phase Detector Polarity

D

I

CPo

IF

2330L RF

2331L/32L RF

Pwdn

(Note 11)

(Note 9)

(Note 10)

Prescaler

Prescaler

Prescaler

(Note 9)

0

Negative

Normal Operation

LOW

8/9

32/33

64/65

Pwrd Up

1

Positive

TRI-STATE

HIGH

16/17

64/65

128/129

Pwrd Dn

Note 9: Refer to POWERDOWN OPERATION in Functional Description.

Note 11: PHASE DETECTOR POLARITY

Depending upon VCO characteristics, R16 bit should be set accordingly: (see figure right)

When VCO characteristics are positive like (1), R16 should be set HIGH;

When VCO characteristics are negative like (2), R16 should be set LOW.

VCO Characteristics

DS012806-9

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