Rainbow-electronics MAX2108 Manual do Utilizador descarregar pdf (Página 5)

MAX2108

Direct-Conversion Tuner IC

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NAME FUNCTION

IOUT

Inverting I-Channel Baseband Output

Pin Description

2 IOUT Noninverting I-Channel Baseband Output

3 V

Downconverter +5V Supply. Bypass with a 10pF capacitor to GND as close to the IC as possible. Connect

an additional 0.1µF capacitor in parallel with the 10pF capacitor.

4 GND Ground. Connect to a low-inductance ground plane.

5 V

RF +5V Supply. Bypass with a 22pF capacitor to GND as close to the IC as possible.

RFIN

Inverting RF Input. Connect to a 22pF capacitor in series with a 75Ω resistor to GND.

7 RFIN Noninverting RF Input. Connect via matching network to a 75Ω cable.

8, 9 GND RF Ground. Connect to a low-inductance ground plane.

10 GC

Gain-Control Input. Apply a voltage between 1V and 4V to control the gain of the RF amplifier. Bypass with a

1000pF capacitor to minimize noise on the control line.

11 PS_SEL

Prescaler Modulus Control. Drive PS_SEL <0.5V to operate in divide-by-33 mode. Drive PS_SEL >2.4V to

operate in divide-by-32 mode.

12 V

Prescaler +5V Supply. Bypass with a 1000pF capacitor to GND.

PSOUT

Inverting Prescaler Output

14 PSOUT Noninverting Prescaler Output

15 GND Prescaler Ground. Connect to a low-inductance ground plane.

16 GND Local Oscillator Ground. Connect to a low-inductance ground plane.

17, 20 N.C. No Connection. Do not make any connection to this pin.

Inverting LO Input

19 LO Noninverting LO Input

21 V

Local Oscillator +5V Supply. Bypass with a 22pF capacitor and a 0.1µF capacitor to pin 16.

22 GND Downconverter Ground. Connect to a low-inductance ground plane.

23 QOUT Noninverting Q-Channel Baseband Output

QOUT

Inverting Q-Channel Baseband Output

1 2 3 4 5 6 7 8 9 10 11 12

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Rainbow-electronics MAX2108 Manual do Utilizador Página 5