NEC UPC2533GS-02, UPC2533GS-01 Datasheet

DATA SHEET

BIPOLAR ANALOG INTEGRATED CIRCUIT

µ

PC2533

AM TUNER FOR ELECTRONIC TUNING CAR RADIOS

The µPC2533 is an IC developed as an AM tuner for car stereos and car radios. It employs an up-conversion type double super-heterodyne configuration (IF1 = 10.71 MHz, IF2 = 450 kHz).

The internal configuration consists of the MIX1 block (MIX1, OSC1, Buff1), MIX2 block (MIX2, OSC2, Buff2), IF amplifier, detection circuit, AGC circuit, signal meter circuit, SD (station detector) circuit, and Lo/DX (short range/long range) circuit.

Features

• Possible to select stations using only one varactor diode with narrow variable capacitance range

• Tracking adjustment unnecessary

• Coil switching between LW (long wave) and MW (middle wave) unnecessary

• Less sensitivity deviation due to tracking error

• High S/N: 60 dB

• Signal meter output with good linearity

• Signal meter output voltage inclination setting possible by external resistor.

• Can be used with IF (intermediate frequency) counter turning system or high/low tuning system.

Type Number

µ

PC2533GS-01 Set by pin No. 7 Set by pin No. 9 Depends on SD SD sensitivity of IF counter

µ

PC2533GS-02 Set by pin No. 7 Set by pin No. 9 Tilt of the signal meter

•LO/DX function on-chip

• Since IFT (intermediate frequency transformer) turn ratio is free from limitation for matching of ceramic filter

impedance, it is easy to design MIX gain with IFT.

IF Counter Output High/Low Output

SD Sensitivity Setting

Signal Meter Voltage Inclination Setting

sensitivity setting system and high/low system

can be set independently.

voltage can be set without regard to SD sensitivity.

Remarks

The information in this document is subject to change without notice.

Document No. S11989EJ4V0DS00 (4th edition) Date Published August 1998 N CP(K) Printed in Japan

The mark shows major revised points.

©

1993

Ordering Information

Part Number Package

µ

PC2533GS-01 36-pin plastic shrink SOP (300 mil)

µ

PC2533GS-02 36-pin plastic shrink SOP (300 mil)

Block Diagram

RF AGC1

RF AGC2

RF AGC T.C.

MIX1IN

MIX1OUT

MIX1BYP

Buff1IN

35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 20 1936

GND

Buff1OUT

MIX2BYP

MIX2OUT

MIX2IN

Buff2IN

Buff2OUT

IF AGC T.C.

IF2IN

µ

PC2533

RF AGC driver

L

OSC

OSC 1

Buff

2345671 8 9101112131415161718

1

ref

ALC

V

OSC1 Buff

MIX 1 Buff 1 MIX 2 Buff 2

RF AGC detector

AGC comparator

O

/DX

Station detector

SD ACOUT

SD ACadj [SDadj]

SD IFIN

/DX

O

L

SEEK

Remarks 1. Bold lines indicate flow of audio signal.

2.µPC2533GS-02 pin names are in parentheses. Pins not in parentheses are used in both the

µ

PC2533GS-01 and µPC2533GS-02.

Signal meter

OSC 2 Detector

OSC2 (B)

SD DCOUT

SD DCadj [SMOUT]

OSC2 (E)

MIX 2 AGC

Time constant selector switch

2

ref

V

MIX2AGC T.C.

(AF)

O

V

GND

IF amplifier

IF AGC

CC

V

IF2OUT

2

Pin Configuration (Top View)

36-pin plastic shrink SOP (300 mil)

•µPC2533GS-01

•µPC2533GS-02

µ

PC2533

OSC1 Buff

ALC V

ref

L

O

/DX

SEEK

SD ACOUT

SD ACadj [SDadj]

SD IFIN

SD DCadj [SMOUT]

SD DCOUT

OSC2 (B) OSC2 (E)

V

ref

MIX2AGC T.C.

O

(AF)

V

GND

V

IF2OUT

1 2 3

1

4 5 6 7 8

9 10 11 12 13

2

14 15 16 17

CC

18

RF AGC1

36 35

RF AGC2

34

RF AGC T.C.

33

MIX1IN

32

MIX1OUT

31

MIX1OUT

30

MIX1BYP

29

Buff1IN

28

GND

27

Buff1OUT

26

MIX2BYP

25

MIX2OUT

24

MIX2OUT

23

MIX2IN Buff2IN

22 21

Buff2OUT

20

IF AGC T.C.

19

IF2IN

RemarkµPC2533GS-02 pin names are in parentheses. Pins not in parentheses are used in both the

µ

PC2533GS-01 and µPC2533GS-02.

3

1. Pin Description

V

ref

5 kΩ

5

60 kΩ

Names and symbols in parentheses indicate pin names for µPC2533GS-02. Names and symbols not in

parentheses are pin names used in both the µPC2533GS-01 and µPC2533GS-02.

Pin No. Symbol Name Equivalent Circuit

1 OSC1 Buff OSC1 Buff output

2 ALC OSC1 ALC

ZO = 30 Ω ±20 %

V

CC

1

VCC

2

µ

PC2533

(1/7)

3Vref1 Reference voltage Reference voltage (5.3 V) 4LO/DX LO/DX control

4

5 SEEK Seek request

4

V

CC

Pin No. Symbol Name Equivalent Circuit

V

CC

7

5 kΩ

( PC2533GS-01)

µ

6 SD ACOUT SD AC output

O

= 20.5 kΩ ±20 %

R

500 Ω

6

20 kΩ

7 SD ACadj SD AC sensitivity setting

(and signal meter ouput)

µ

PC2533

(2/7)

[SDadj] [SD AC sensitivity and SD DC

sensitivity setting]

8 SD IFIN SD IF input

µ

( PC2533GS-02)

V

CC

5 kΩ

7

Vref

60 kΩ

500 Ω

5.2 V

8

5

Pin No. Symbol Name Equivalent Circuit

V

CC

9

5 kΩ

( PC2533GS-01)

µ

9 SD DCadj SD DC sensitivity setting

(and signal meter output)

µ

PC2533

(3/7)

[SMOUT] [Signal meter output]

10 SD DCOUT SD DC output (Active high)

11 OSC2 (B) OSC2 (base) 12 OSC2 (E) OSC2 (emitter)

µ

( PC2533GS-02)

V

5 kΩ

9

10

Z

IN

V

ref

CC

5.2 V

= 5 kΩ ±20 % 11

V

CC

6

ZO = 240 Ω ±20 %

12

13 Vref2 Reference voltage Reference voltage (6.0 V)

Pin No. Symbol Name Equivalent Circuit

18

14 MIX2AGC T.C. MIX2 AGC smoothing

ref

V

14

T

= 1 kΩ ±20 %

R

T

µ

PC2533

(4/7)

15 VO(AF) Audio output

16 GND Ground GND (low frequency) 17 VCC Power supply voltage VCC 18 IF2OUT IF amplifier output

19 IF2IN IF amplifier input

V

CC

ZO = 300 Ω ±20 %

20

15

19

20 IF AGC T.C. IF AGC input

VCC

15

T

R

20

RT = 100 kΩ ±20 %

7

Pin No. Symbol Name Equivalent Circuit

21

Z

O

= 2 kΩ ±20 %

22

V

ref

ZIN = 30 kΩ ±20 %

21 Buff2OUT 2nd IF burffer output

22 Buff2IN 2nd IF buffer input

23 MIX2IN MIX2 input

µ

PC2533

(5/7)

24 MIX2OUT MIX2 output 25 MIX2OUT MIX2 output

26 MIX2BYP MIX2 bypass

27 Buff1OUT 1st IF buffer output

23

Z

IN

25 24

26

Z

IN

= 330 Ω ±20 %

26

= 330 Ω ±20 %

8

27

Z

O

= 330 Ω ±20 %

Pin No. Symbol Name Equivalent Circuit

ZIN = 1.2 kΩ ±20 %

33 30

34

Z

O

= 12 kΩ ±20 %

28 GND Ground GND (high frequency) 29 Buff1IN 1st IF buffer input

V

ref

29

Z

IN = 15 kΩ ±20 %

30 MIX1BYP MIX1 bypass

33 30

µ

PC2533

(6/7)

31 MIX1OUT MIX1 output 32 MIX1OUT MIX1 output

33 MIX1IN MIX1 input

34 RF AGC T.C. RF AGC smoothing

ZIN = 1.2 kΩ ±20 %

31 32

V

ref

9

Pin No. Symbol Name Equivalent Circuit

35 RF AGC2 RF AGC output (cascade base)

Vref

O = 11 kΩ ±20 %

Z

35

36 RF AGC1 RF AGC output (PIN diode)

µ

PC2533

(7/7)

36

O

= 22 kΩ ±20 %

Z

10

2. Operation of Each Block

2.1 FR Amplifier Circuit Block

VCC

R1

L3

R2

L1

Q1

Q2

L2

C1

+

C9

C8

Fig. 2-1 RF Ampliier Circuit

LPF

L4 L5

C3 C4 C5

C6

33

30

C7

35

36

MIX1

From MIX2

RF AGC L

O/DX

µ

PC2533

Note

C2

34

+

4

Note LO : 3 V or higher

DX : 1 V or lower

In the AM band, the capacitance of a car radio antenna depends on its length, diameter, cable length, etc. Therefore,

µ

J-FET is used in the

PC2533 to raise RF input impedance.

Since the µPC2533 raises the first IF (intermediate frequency) to 10.71 MHz, there is no need for a tuning circuit between the RF amplifier circuit and MIX1. Instead, it employs an LPF (about 6 MHz) consisting of L4, L5 and C3 to C5 between the RF amplifier circuit and MIX1 in order to cut image frequency (21.4 MHz or higher). Because this allows a wide-band RF amplifier circuit to be configured without using a tuning circuit, frequency sensitivity deviation can be minimized to a high degree.

The AGC circuit consists of RF AGC1 by the PIN diode connected to the FET gate and RF AGC2 by the cascade transistor Q1. Use a low-noise transistor even with low current for the cascade transistor Q1 (if a high-noise one is used, the S/N ratio deteriorates).

Remark Set bias voltage for cascade transistor Q1 to V

C > VB.

11