ISDB-T Single-Segment Low-IF Tuners

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13

Table 4. VCO Register

BIT NAME

BIT LOCATION

(0 = LSB)

RECOMMENDED

DEFAULT

FUNCTION

VCO[1:0]

7, 6

11

Control which VCO is activated when using manual VCO programming mode.

This will also serve as the starting point for the VCO autoselect mode.

00 = select VCO 0

01 = select VCO 1

10 = select VCO 2

11 = select VCO 3

VSB[2:0]

5, 4, 3

011

Select a particular sub-band for each of the on-chip VCOs. Together with the

VCO[2:0] bits a manual selection of a VCO and a sub-band can be made. This

will also serve as the starting point for the VCO autoselect mode.

000 = select sub-band 0

001 = select sub-band 1

010 = select sub-band 2

011 = select sub-band 3

100 = select sub-band 4

101 = select sub-band 5

110 = select sub-band 6

111 = select sub-band 7

ADL

2

0

Enables or disables the VCO tuning voltage ADC latch when the VCO autoselect

mode (VAS) is disabled.

0 = disables the ADC latch

1 = latches the ADC value

ADE

1

0

Enables or disables VCO tuning voltage ADC read when the VCO autoselect

mode (VAS) is disabled.

0 = disables ADC read

1 = enables ADC read

LTC

0

0

Sets the source current for the VAS time constant.

0 = 1µA

1 = 2µA