AIT1042RS38P9 View Datasheet(PDF) - ANADIGICS

Part Name

Description

Manufacturer

AIT1042RS38P9

Integrated Digital Tuner with RF and IF Gain Control

ANADIGICS 

Downconverter Main and Reference Divider Registers

AIT1042

The downconverter main and reference divider registers are used to set the A, B and R counters in the

downconverter synthesizer. The output frequency for the synthesizer is computed using the following

equation:

fosc

=

[(64)(B) +

R

A]

fxtal

where:

fOSC is the downconverter local oscillator (LO2) frequency

B is the divide ratio of the B counter (2 to 2047 inclusive)

A is the divide ratio of the A counter (0 < A < P-1, A < B)

fXTAL is the frequency of the reference crystal oscillator

R is the divide ratio of the R counter (2 to 4095 inclusive)

The preset modulus of the prescalar is 64 and is not programmable.

In the main divider register, the A counter is set via Bits 2-8 and the B counter is set with Bits 9-19. In the

reference divider register, the R counter is set with Bits 2-13. The remaining bits must use the fixed values

indicated in Tables 15 and 16.

MSB

Table 15: Downconverter Main Divider Register

PLL2_Main (Downconverter Main Divider Register)

First data byte

Second data byte

Third data byte

23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2

0000

B counter

A counter

LSB

10

01

MSB

Table 16: Downconverter Reference Divider Register

PLL2_Ref (Downconverter Reference Divider Register)

First data byte

Second data byte

Third data byte

23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2

000 100 1000

R counter

LSB

10

00

PRELIMINARY DATA SHEET - Rev 1.0

15

02/2009

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