Complete, Direct-Conversion

Tuner for DVB-S2 Applications

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Table 8. PLL Register

BIT NAME

BIT LOCATION (0 = LSB)

DEFAULT

FUNCTION

D24

7

1

VCO divider setting.

0 = Divide by 2. Use for LO frequencies

≥ 1125MHz.

1 = Divide by 4. Use for LO frequencies < 1125MHz.

CPS

6

1

Charge-pump current mode.

0 = Charge-pump current controlled by ICP bit.

1 = Charge-pump current controlled by VCO autoselect (VAS).

ICP

5

0

Charge-pump current.

0 = 600µA typical.

1 = 1200µA typical.

X

4–0

X

Don’t care.

Table 9. VCO Register

BIT NAME

BIT LOCATION (0 = LSB)

DEFAULT

FUNCTION

VCO[4:0]

7–3

11001

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

This also serves as the starting point for the VCO autoselection (VAS) mode.

VAS

2

1

VCO autoselection (VAS) circuit.

1 = Enable VCO selection controlled by autoselection circuit.

ADL

1

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

0

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.

Table 10. Lowpass Filter Register

BIT NAME

BIT LOCATION (0 = LSB)

DEFAULT

FUNCTION

LPF[7:0]

7–0

01001011

Sets the baseband lowpass filter 3dB corner frequency.