MC13156FB View Datasheet(PDF) - Motorola => Freescale

Part Name

Description

Manufacturer

MC13156FB

Wideband FM IF System

Motorola => Freescale 

MC13156

45 MHz Narrowband Receiver

The above application examples utilize a 10.7 MHz IF. In

this section a narrowband receiver with a 455 kHz IF will be

described. Figure 23 shows a full schematic of a 45 MHz

receiver that uses a 3rd overtone crystal with the on–chip

oscillator transistor. The oscillator configuration is similar to

the one used in Figure 17; it is called an impedance inversion

Colpitts. A 44.545 MHz 3rd overtone, series resonant crystal

is used to achieve an IF frequency at 455 kHz. The ceramic

IF filters selected are Murata Erie part # SFG455A3. 1.2 kΩ

chip resistors are used in series with the filters to achieve the

terminating resistance of 1.4 kΩ to the filter. The IF

decoupling is very important; 0.1 µF chip capacitors are used

at Pins 6, 7, 11 and 12. The quadrature detector tank circuit

uses a 455 kHz quadrature tank from Toko.

The 12 dB SINAD performance is –109 dBm for a fmod =

1.0 kHz and a fdev = ±4.0 kHz. The RSSI dynamic range is

approximately 80 dB of linear range (see Figure 24).

Receiver Design Considerations

The curves of signal levels at various portions of the

application receiver with respect to RF input level are shown

in Figure 28. This information helps determine the network

topology and gain blocks required ahead of the MC13156 to

achieve the desired sensitivity and dynamic range of the

receiver system. In the application circuit the input third order

intercept (IP3) performance of the system is approximately

–25 dBm (see Figure 29).

Figure 23. MC13156DW Application Circuit at 45 MHz

1.8 µH

+

(6)

1.0 µ

45 Hz

RF Input

33 p

(1)

0.33 µH

1

SMA 180 p

2

Mixer

10 n 1.2 k

3

(2) 455 kHz

Ceramic

Filter

4 VCC

Bias

10 n

24

56 p

23

(5) 0.416 µH

39 p 10 k

VEE 22

10 n

21

100 k

470 k

(4) 3rd OT

XTAL

44.545

MHz

Carrier

Detect

5

0.1 µ

6

0.1 µ

7

1.2 k

8

IF Amp

Data

Slicer

Bias

20

47 k

10 n

19

VEE

10 n

18

10 k

17

(2) 455 kHz

VCC

Ceramic

Filter

9 VCC

16

VEE

100 n

RSSI

Output

Data Slicer

Hold

Data

Output

10

0.1 µ

11

0.1 µ

12

LIM Amp

5.0 p

15

14

1.0 n

13

100 k

100 k

Audio To

C–Message

Filter and

Amp.

27 k 180 p

(3)

680 µH

VCC = 2.0 to 5.0 Vdc

NOTES: 1. 0.33 µH Variable Shielded Inductor: Coilcraft part # 7M3–331 or equivalent. +

2. 455 kHz Ceramic Filter: Murata Erie part # SFG455A3.

3. 455 kHz Quadrature Tank: Toko part # 7MC8128Z.

4. 3rd Overtone, Series Resonant, 25 PPM Crystal at 44.540 MHz.

5. 0.416 µH Variable Shielded Inductor: Coilcraft part # 143–10J12S.

6. 1.8 µH Molded Inductor.

1.0 µ

MOTOROLA WIRELESS SEMICONDUCTOR

15

SOLUTIONS – RF AND IF DEVICE DATA

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