UPC2533GS Ver la hoja de datos (PDF) - NEC => Renesas Technology

Número de pieza

componentes Descripción

Fabricante

UPC2533GS

AM TUNER FOR ELECTRONIC TUNING CAR RADIOS

NEC => Renesas Technology 

µPC2533

2.2 MIX1 Block

Fig. 2-2 MIX1 Block

T1

VT

+

To 10.7 MHz

BPF

VCC

From

LPF

23

31

32

17

29

27

Q101

Q102

Q104

Q103

R11

OSC1

Q105

Q109

1

Q108

Q106 Q107

R109

R110

R112

Buff1

Note

R111

R107

R108

28

33

To RF AGC circuit (Fig. 2-4)

30

Note Output impedance and input impedance of Buff1 are 330 Ω and 15 kΩ, respectively.

MIX1 (Q101 to Q108) is a DBM (double balanced mixer).

MIX1 output is supplied to 10.7 MHz ceramic filter via Buff1 (output impedance: 330 Ω) for impedance matching.

The local oscillation signal is applied to the bases of Q101 to Q104, and the RF signal to the base of Q105. MIX1

(Q101 to 108) multiplies the local oscillation signal by RF signal, and converts to the resonance frequency of IFT T1

for output.

The local oscillation signal is output from pin 1 via Q109 (OSC Buff). It has an amplitude of 110 dBµV and can

be directly input to CMOS LSI for use by the PLL synthesizer.

The RF signal applied to the base of Q105 is also input to the detector of the RF AGC circuit.

12

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