2.4.4 TRI-STATE ID

AUXILIARY SYNTHESIZER CHARGE PUMP TRI-STATE CURRENT

Aux R[19]

The TRI-STATE ID

output state. This happens asynchronously with the change in the TRI-STATE ID

Furthermore, the TRI-STATE ID

powerdown mode.

Control Bit

Register Location

Description

Function

01

TRI-STATE ID

Aux R[19]

Aux Charge Pump

TRI-STATE Current

Aux Charge Pump

Normal Operation

Aux Charge Pump

Output in High

Impedance State

2.5 AUXILIARY N REGISTER

The Aux N register contains the Aux N_CNTRA, Aux N_CNTRB, PRE Aux, and PWDN Aux control words. The Aux N_CNTRA

and Aux N_CNTRB control words are used to setup the programmable feedback divider. The detailed description and

programming information for each control word is discussed in the following sections.

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

Aux

N

PWDN

Aux

PRE

Aux

Aux N_CNTRB[12:0]

Aux N_CNTRA[4:0]

0

1

2.5.1 Aux N_CNTRA[4:0]

AUXILIARY SYNTHESIZER SWALLOW COUNTER (A COUNTER)

Aux N[2:6]

The Aux N_CNTRA control word is used to setup the Aux synthesizer’s A counter. The A counter is a 5-bit swallow counter used

in the programmable feedback divider. The Aux N_CNTRA control word can be programmed to values ranging from 0 to 31.

Divide Ratio

Aux N_CNTRA[4:0]

43210

000000

100001

••••••

31

11111

2.5.2 Aux N_CNTRB[12:0]

AUXILIARY SYNTHESIZER PROGRAMMABLE BINARY COUNTER (B COUNTER)

Aux N[7:19]

The Aux N_CNTRB control word is used to setup the Aux synthesizer’s B counter. The B counter is a 13-bit programmable binary

counter used in the programmable feedback divider. The Aux N_CNTRB control word can be programmed to values ranging from

3 to 8191.

Divide

Ratio

Aux N_CNTRB[12:0]

12

11

10

9

876543210

3000

0

000000011

4000

0

000000100

••••

•

•••••••••

8191

1

1

1

1

111111111

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