2.4 IF R REGISTER

The IF R register contains the IF R_CNTR, PD_POL IF, ID

compose the F

following sections. IF R_CNTR[14:0]

Reg. Most Significant Bit

SHIFT REGISTER BIT LOCATION

Least Significant Bit

21

20

19

18

17

16

15

14

13

12

11

10

9876543210

Data Field

Address

Field

IF

R

FoLD0 FoLD2

TRI-

STATE

IDo

IF

IDo

IF

PD_

POL

IF

IF R_CNTR[14:0]

0

0

2.4.1 IF R_CNTR[14:0]

IF SYNTHESIZER PROGRAMMABLE REFERENCE DIVIDER (R COUNTER)

IF R[2:16]

The IF reference divider (IF R_CNTR) can be programmed to support divide ratios from 3 to 32767. Divide ratios less than 3 are

prohibited.

Divide Ratio

IF R_CNTR[14:0]

14

13

12

11

10

9876543210

3

000000000000011

4

000000000000100

•

•••••••••••••••

32767

111111111111111

2.4.2 PD_POL IF

IF SYNTHESIZER PHASE DETECTOR POLARITY

IF R[17]

The PD_POL IF bit is used to control the IF synthesizer’s phase detector polarity based on the VCO tuning characteristics.

Control Bit

Register Location

Description

Function

01

PD_POL IF

IF R[17]

IF Phase Detector

Polarity

IF VCO Negative

Tuning

Characteristics

IF VCO Positive

Tuning

Characteristics

IF VCO Characteristics

10136609

2.4.3 ID

IF SYNTHESIZER CHARGE PUMP CURRENT GAIN

IF R[18]

The ID

Control Bit

Register Location

Description

Function

01

ID

IF R[18]

IF Charge Pump

Current Gain

LOW

0.95 mA

HIGH

3.80 mA

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