Direct-Conversion TV Tuner

4

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AC ELECTRICAL CHARACTERISTICS (continued)

noted.) (Note 1)

PARAMETER

SYMBOL

CONDITIONS

MIN

TYP

MAX

UNITS

SIGMA-DELTA FRACTIONAL-N SYNTHESIZER

REFERENCE OSCILLATOR

Frequency

4

27

MHz

Input Impedance

10

k

Ω

Voltage Gain

30

V/V

Output Impedance

15

Ω

Buffered Output

10k

Ω || 10pF load

0.7

DIVIDERS

RF N Divider Ratio

(Notes 12, 13)

12

251

—

RF R Divider Ratio

VHF band operation requires R divider = 2

1

2

—

Fractional-N Resolution

20

Bits

LO PHASE DETECTOR AND CHARGE PUMP

Phase-Detector Frequency

4

27

MHz

Gain = 0

600

Charge-Pump Current

Gain = 1

1200

µA

Charge-Pump Tri-State Current

-10

+10

µA

Charge-Pump Compliance

Range

Charge-pump positive to negative current

matching of

≤ ±5%

0.4

0.4

V

LOCAL OSCILLATOR

Tuning Frequency Range

Tank Frequency

2160

4400

MHz

VCO Dividers

4

16

—

BASEBAND STAGE

Nominal Output Voltage

(Note 2)

1

1dB Output Compression Point

Differential voltage at 3MHz

1.6

2

Output Impedance

Differential

60

Ω

Passband AGC Range

BB_AGC = 0.5V to 2.85V

30

50

dB

Passband Cutoff Attenuation

At 3.8MHz (UHF Mode);

at 3.325MHz (VHF Mode)

2

5

dB

Passband Differential Gain Error

2MHz to 3.8MHz, I channel vs. Q channel

(UHF mode)

-0.45

+0.45

dB

Passband Group Delay

From DC to 3.8MHz over any 1.1kHz band

(UHF mode)

5

ns

Group Delay Mismatch

From 0.1MHz to 3.8MHz, I channel vs. Q

channel (UHF mode) (Note 9)

< 2

ns