Direct-Conversion TV Tuner

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13

Register Descriptions

N-Divider Integer (Register Address 0x00)

N<7:0>: VCO Integer-N Divider Ratio

N-Divider Frac2 (Register Address 0x01)

MP: Minimum CP Pulse Width. Always set to 0

(factory use only).

LI1, LI0; CP Linearity Control. Always set to 00

(factory use only).

INT: Integer Mode ON/OFF. Set to 0 for normal

operation.

F<19:16>: MSB of Main Divider Fractional Divide Ratio

N-Divider Frac1, Frac0

(Register Address 0x02, 0x03)

F<15:0> 16 LSB of Main Divider Fractional Divide

Ratio

Tracking Filter Series Capacitor

(Register Address 0x04)

TFS<7:4>: Tracking Filter Parallel Capacitor.

TFS<3:0>: Tracking Filter Series Capacitor.

See the RF tracking filter description in the

Applications

Information section.

Tracking Filter Parallel Capacitor and VCO Control

(Register Address 0x05)

VCO_DIV1, VCO_DIV0: VCO Post Divider

00 = Divide by 4 use for RF frequencies of 540 to

868 MHz

01 = Divide by 8 use for RF frequencies of 470 to

550 MHz

10 = Divide by 16 use for RF frequencies of 170 to

230 MHz

11 = Divide by 32 is not used

RFS: RF Input Select

0 = RFIN2 selected

1 = RFIN selected

TF_BS: Tracking Filter Band Select

1 = VHF band

0 = UHF band

TFP<4:0>: Tracking Filter Shunt Capacitor

See the RF tracking filter description in the

Applications

Information section.

PLL Configuration (Register Address 0x06)

LF_DIV2, LF_DIV1, LF_DIV0: Prescaler for Internal

Low Frequency Clocks

000 - 110 = Divided by 8 to 14 for REF crystal fre-

quencies of 15MHz to 28MHz

111 = Divide by 2 for REF crystal frequencies of

4MHz

ADLY1, ADLY0: VCO Autotuner Delay Selection

CPS: Charge-Pump Current Mode

0 = Controlled by ICP bit

1 = Controlled by VCO autotuner

ICP: Charge-Pump Current

0 = 600µA

1 = 1200µA

RDIV: PLL Reference Divider Ratio

0 = Divide by 1

1 = Divide by 2

Test Functions (Register Address 0x07)

CP_TST<2:0>: Charge-Pump Test Modes

000 = Normal operation

100 = Low impedance*

101 = Source

110 = Sink

111 = High impedance

LD_MUX: Lock-Detector Mode

000 = Normal operation: high = PLL locked,

low = unlocked

001 = Monitor N-divider output, post-divided by 2

010 = Monitor R-divider output*

011 = Modulator test vector output

(factory use only)

1XX = Bias current trim (factory use only)

*

Not production tested.