Sony CXA1742Q Datasheet

CXA1742Q

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IF Amplifier for Analog Cellular Communications

Description

The CXA1742Q is an analog cellular(AMPS) FM IF

IC which include an IF filter.

Features

• Include a ceramic filter function, which is normally

mounted externally.

• Quadrature detection discriminator function.

• This IC has almost all IF functions and is ideal for

reduction in set size because of few external parts required.

• Channel filter conforming to the AMPS standard.

• Wide operating voltage range (2.7 V to 3.6 V) and

low current consumption (Icc=10 mA (typ.) when Vcc= 3 V).

• Wide range and excellent temperature characteristics for the RSSI (receiving signal strength indicator).

Absolute Maximum Ratings (Ta = 25°C)

• Supply voltage VCC 5V

•Operating temperature Topr –35 to +85 °C

• Storage temperature Tstg –65 to +150 °C

• Allowable power dissipation

Operating Conditions

Supply voltage VCC 2.7 to 3.6 V

40 pin QFP (Plastic)

PD 500 mW

Applications

Ideally suited for cellular phones, particularly handheld sets.

Structure

Bipolar silicon monolithic IC

Sony reserves the right to change products and specifications without prior notice. This information does not convey any license by any implication or otherwise under any patents or other right. Application circuits shown, if any, are typical examples illustrating the operation of the devices. Sony cannot assume responsibility for any problems arising out of the use of these circuits.

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E95119-TE

Block Diagram and Pin Configuration

CXA1742Q

(Top View)

T4

T5

CC1

V

GND1

T6

FADJ1

FADJ2

SGND

BPFPS1

31

32

33

34

35

36

37

38

39

T3

BIAS

MIXADJ1

PSN

BPF0

BPF1

MIXADJ2

MIXPS

MIXIN

MIXER

1/

2

LIM DET

RSSI

GND

AGC

CC

V

IFPS

23 22 212425262730 2829

RF AMP

OSC

IFIN

GND

20

19

18

17

16

15

14

13

12

XTALIN

XTALOUT

AGCPS

VREF

RSSIPS

T2

RSDETPS

T1

GND2

BPFPS2

40

1 2 3 4 5 6 7 8 9

NC

SW

BPFO

LIMIN

AUDIO

RSSI

10

IF2

LIMPS

GADJ(RSSI)

11

CC2

V

Note) Pins 21 and 25 are connected via the IC internal wiring.

Pins 12, 21 and Pins 25, 34 are connected via IC internal resistors. When designing a PCB, ensure that all GND pins of IC are connected to the GND on PCB with its connection wiring distance minimized.

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CXA1742Q

Pin No. Symbol

1SW

2NC 3 BPFO 1.83V

Pin voltage I/O

DC AC

resistance

31

34

Equivalent circuit Description

Used at the GND potential.

20µA

50k

1

50k

VREF

GND

Not intemally connected. BPF output. Connect to Pins 4,5.

33

147

3

4 LIMIN Open 5 Base

6 AUDIO 1.85V

B.P.F N.F.B Network

LIM

RSSI

1k

147

11

34

Input of BPF output. The DC bias is applied from pin3 when the output of BPF is connected to

4

them.

5

Outputs an AUDIO signal which is FM-detected.

6

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12

CXA1742Q

Pin No. Symbol

7 RSSI 1.1 V

8 GADJ 0.2 V

Pin voltage I/O

DC AC

resistance

Equivalent circuit Description

RSSI output. Outputs a

11

DC voltage in accordance with the signal input to the RF amplifier.

147

7

12

Adjusts the RSSI amplifier gain.

8

147

7

9 IF2 1.07 V

10 LIMPS 1.82 V

147

11

12

Limiter operation monitor. Not used normally.

9

Connects a limiter

11

integrating capacitor.

10

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12

CXA1742Q

Pin No. Symbol

11 VCC2 3.0 V

12 GND2 0 V 13 T1

14 RSDETPS 1.35 V

15 T2

Pin voltage I/O DC AC

resistance

Equivalent circuit Description

Power supply. Supplies current to the LIM, DET, and RSSI circuits. Ground. IC operation check.

Connects an RSSI detector integrating capacitor.

11

147

14

12

IC operation check.

16 RSSIPS 1.83 V

17 VREF 1.25 V

reference voltage used in the internal circuit

11

16

12

Connects an RSSI integrating capacitor.

Monitor for the reference

33

voltage used in the internal circuit.

17

When connected to an external capacitor, this pin also functions to lower the reference voltage dynamic impedance.

34

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CXA1742Q

Pin No. Symbol

18 AGCPS 0.233 V

19 XTALOUT

20 XTALIN 2.96 V

Pin voltage I/O

DC AC

resistance

VREF

20

Equivalent circuit Description

Connects an AGC

33

integrating capacitor.

18

34

15

Connect a crystal oscillator to form a Colpitts-type

24

147

10k

15p

10k

oscillator circuit. When an external oscillator is used, its signal

19

must be connected to Pin

20.

21 GND 0 V 22 IFIN 1.25 V

23 IFPS 1.25 V

24 VCC 3.0 V

25 GND 0 V

25

22

VREF

21

Ground. RF amplifier input. The relationship between IFIN

24

(Pin 22) and IFPS (Pin 23) is designed so that the IC internal stray capacitance

23

1.5k1.5k

is small. Therefore, if Pins 22 and 23 are used for balance input, the common-mode

2521

rejection deteriorates.

Power supply. Supplies current to the RF AMP, MIXER, OSC, and 1/2 DIVIDER circuits. Ground.

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