SONY CXA1538M

CXA1538M/N/S
FM Stereo/AM Radio
For the availability of this product, please contact the sales office.
Description
The CXA1538M/N/S is high performance one-chip
bipolar ICs designed for FM stereo/AM radios.
These include an FM/AM front end, FM/AM IF
amplifier, FM/AM detection output and FM stereo
demodulator output.
CXA1538M
30 pin SOP (Plastic)
Features
• Low current consumption
(In FM mode ID=11.0 mA, in AM mode 8.5 mA,
VCC=6.0 V)
• Built-in LED drive circuit for tuning
• Built-in LED drive circuit for stereo indicator
• Built-in muting circuit for the FM band
• Few external parts
CXA1538S
30 pin SDIP (Plastic)
CXA1538N
30 pin SSOP (Plastic)
Absolute Maximum Ratings (Ta=25 °C)
• Supply voltage
VCC
14
V
• Operating temperature Topr
–10 to +60
°C
• Storage temperature
Tstg –55 to +150 °C
• Junction temperature
Tjmax
125
°C
• Allowable power dissipation
PD CXA1538M
500
mW
CXA1538N
410
mW
CXA1538S
1050
mW
Recommended Operating Conditions
Supply voltage
VCC
2 to 9
V
Structure
Bipolar silicon monolithic IC
Block Diagram
GND
PLL
LPF 2
MPX
REG
VCO
30
29
28
27
FM
DISCRI MUTE
26
25
AM
OSC
AFC
FM
OSC
REG
FM
RF
24
23
22
21
20
MULTIPLEX
REGULATOR
VCO
FM/AM
FE
GND FE OUT
AM RF FM RF
IN
IN
19
18
17
16
14
15
FM FE
REGULATOR
AM FE
PD 1
MUTING
1/2 COUNTER
DC
AMP
PD 2
FM IF/
DISCRI
AUTO
BLEND
BU
AMP
BU
AMP
DECODE AMP
M/ST
SW
AM IF/DET
RIPPLE FILTER
ST
IND
1
2
3
4
5
6
7
PLL
LPF1
PILOT
DET
LPF2
PILOT
DET
LPF2
ST
IND
Rch
OUT
Lch
OUT
VCC
DETUNE
MUTING
CONTROL
DC
AMP
8
9
RIPPLE AGC
FILTER AFC 1
VCO
CHECK
TUNING IND
10
11
12
13
AGC
AFC 2
GND
TUNE
IND
FM IF
IN
PD : PHASE DETECTOR
BU : BUFFER
FE : FRONT END
AM IF BAND
IN
SELECT
DET : DETECTOR
IND : INDICATOR
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.
—1—
E93313D8X
CXA1538M/N/S
Pin Description and Equivalent Circuit
No.
1
Symbol
Pin Voltage (V)
VCC=3 V VCC=6 V
FM AM FM AM
Equivalent circuit
Description
MPX REG
PLL LPF1
26k
26k
0.97 0.97 0.97 0.97
29
PLL LPF2
2
PILOT
DET LPF1
LPF for PLL
29
1
0.95 0.95 0.95 0.95
LPF’s C (1µF) for PILOT DET
inserted between pins 2 and 3
3
3
PILOT
DET LPF2
2
0.95 0.95 0.95 0.95
MPX REG
4
ST IND
VCO CHECK
Stereo indicator drive circuit
and output for VCO check
4
6k
1.6 1.6 4.5 4.5
VCO
5
Rch OUT
0.66 0.66 1.5 1.5
Stereo Rch output pin
5
6
6
Lch OUT
0.66 0.66 1.5 1.5
Stereo Lch output pin
7
VCC
3.0 3.0 6.0 6.0
Supply pin
8
Ripple
FILTER
17k
2.7 2.7 4.0 4.0
17k
8
140k
Ripple filter
33k
9
AGC/AFC1
1.32 1.15 1.32 1.15
9
22k
50k
3.25k
10
AGC/AFC2
1.15 1.47 1.15 1.47
25k
—2—
10
AFC pin in J band, determines time
constant of AGC in AM (depending on
external capacitor).
AFC pin in W band, determines time
constant of AGC in AM (depending
on external capacitor).
CXA1538M/N/S
No.
Symbol
Pin Voltage (V)
VCC=3 V VCC=6 V
FM AM FM AM
11
GND
0
0
0
25
MUTE
0.05 0.01 0.05 0.01
12
TUNE IND
1.6 1.6 4.5 4.5
13
FM IF IN
Equivalent circuit
0
Description
25
Time constant for muting
provided
11
12
15
FM/AM tuning indicator drive
circuit
FM IF input pin
33C
1.35
0
1.35
15
0
GND of FM/AM IF and DET
stage
13
3k
BAND
SELECT
FM/AM band switching pin :
AM at GND and FM at OPEN
1k
14
AM IF IN
16
FM/AM
FE OUIT
0
0
0
14
0
AM IF input pin
2k
AM Block
FM Block
0.57 0.2 0.8 0.2
16
AM/FM IF output pin to
connect with IF filter
220
17
FE GND
0
0
0
0
GND of FM/AM front end
3p
20
18
FM RF IN
0.3
0
0.3
0
20
FM RF
1.25 1.25 1.25 1.25
FM RF amplifier circuit for FM
RF input
FM RF amplifier circuit to
connect to RF tank circuit
18
1k
17
FE REG
19
AM RF IN
1.25 1.25 1.25 1.25
AM RF input to connect to bar
antenna
19
GND
—3—
CXA1538M/N/S
No.
21
Symbol
Pin Voltage (V)
VCC=3 V VCC=6 V
FM AM FM AM
Equivalent circuit
Description
REG
Regulator output
21
1.25 1.25 1.25 1.25
1.25V
REG
23
23
AFC
Variable capacitance for AFC
22
22
FM OSC
REG
1.25 1.25 1.25 1.25
FM local oscillation circuit
24
24
AM OSC
REG
1.25 1.25 1.25 1.25
AM local oscillation circuit
26
26
FM DISCRI
27
VCO
2.30 2.70 3.60 4.00
Phase shift circuit to connect
to ceramic discriminator
1k
28
28
MPX REG
30
GND
VCO control pin for stereo
demodulation
27
1.65 1.65 1.65 1.65
0
0
0
MPX REG
Regulator for MPX
0
30
—4—
GND of MPX block
CXA1538M/N/S
Electrical Characteristics
Item
Symbol
(Ta=25 °C, VCC=6 V)
Test
Output waveform
Point
and Test method
Circuit current (1)
ID1
ID
AM no signal
Circuit current (2)
ID2
ID
FM no signal
V1 to
V5 input
short
SW condition
SEP
VD
50 dBµV, 10.7 MHz, 1 kHz,
Max.
Unit
5.0
8.5
12.0
mA
7.0
11.0
15.0
mA
30
40
—
dB
16
23
30
dB
1.8
3.0
5.0
mA
A
28
35
42
dB
B
35.0
77.5
138
mVrms
—
25
31
dBµV
—
0.1
2.0
%
0.1
2.0
%
–50
0
+50
kHz
1.8
3.5
7.0
mA
43
48
dBµV
41
46
dBµV
1
10
41
dB
19
24
28
dB
15
21
29
dBµV
35.0
77.5
138
mVrms
1.3
3.0
7.0
mA
—
0.6
2.0
%
2
3
4
5
6
8
9
10
A
A
A
B
A
B
OFF
A
OFF
A
Separation when VIN3=
Separation
Typ.
1
A
B
/
B
B
22.5 kHz dev input
ON
Attenuation of noise level
FM MUTE
A1
VD
When VIN3=no signal,
A
A
/
OFF
S8 ON/OFF
STEREO
indicator output
FM front end
voltage gain (1)
Is
Is
GV1
VA
VD1
VD
(MONO/STEREO)
output level L, R
FM-IF
knee level
FM-IF distortion
L, R (MONO)
VIN3=60 dBµV, 10.7 MHz CW
OFF
Pilot ON
VIN1=40 dBµV, 100 MHz CW
VA=10.7 MHz CW
VIN3=90 dBµV, 10.7 MHz
FM detection
Min.
A
1 kHz 22.5 kHz dev
/
VD=1 kHz sine wave
B
VIN3=90 dBµV, 10.7 MHz
VD2
VIN3
Input level at –3 dB of 1 kHz
A
22.5 kHz dev output
A
THD1
VD
VIN3=90 dBµV, 10.7 MHz
1 kHz 75 kHz dev
/
B
VD=1 kHz sine wave
FM-IF distortion
L, R (STEREO)
FM-IF center
frequency
∆F1
VF
VIN3=90 dBµV, 10.7 MHz CW
IB1
IB
VIN3=60 dBµV, 10.7 MHz CW
A
deviation
FM meter
current (1)
M→ST
M/ST switching
level by IF input
VI1
Is
38
VIN3=10.7 MHz
ST→M
35
Auto blend
AM front end
voltage gain (2)
AM-IF
voltage gain (4)
AM detection
output level (L, R)
AM meter
current (2)
VI2
VIN3
GV2
VB
GV3
VIN4
VD3
VD
IB2
IB
THD2
VD
(L, R)
B
VB=455 kHz CW
VIN4 level at output of
B
15.5 mVrms
VIN4=85 dBµV 455 kHz
AM detection
output distortion
VIN2=60 dBµV, 1660 kHz CW
B
A
A
A
(1 kHz 30 % MOD)
/
VD=1 kHz sine wave
B
VIN4=85 dBµV, 455 kHz CW
A
VIN2=95 dBµV, 1660 kHz
A
(1 kHz 30 % MOD)
VD=1 kHz sine wave
0 dBµV=1 µV
—5—
—6—
4.7µ
2.2k
0.47µ
PILOT
DET
LPF1
2
PLL
LPF
1
29
PLL
LPF
30
GND
VF
28
MPX
REG
5k
10µ
1µ
3
VM
30k
S1
B
4
IS
0.01µ
A
2k
CF1
S2
25
6
Lch
OUT
MUTE
B
VD
S10
20p
15kHz LPF
19kHz
notch
filter
ID
0.01µ
7
VCC
8
33µ
RIPPLE
FILTER
9
1µ
AGC/
AFC 1
FM
OSC
22
10p
15p
AFC
23
100k
100µ
AM
OSC
24
3.3µ
10p
S8
7.5k 7.5k
A
7.5k
5
Rch
OUT
FM
DISCRI
26
B 100
S9
VCO
27
A
PILOT ST IND
DET
VCO
LPF2 CHECK
VO
Electrical Characteristics Test Circuit
10
AGC/
AFC 2
REG
21
11
GND
FM
RF
20
10p
4.7µ
30p
VH
19
18
13
17
16
FM/AM
FE OUT
S3
14
VIN 4
AM 455kHz
A
S4
15
0.01µ
2k
0.01µF
AM IF
BAND
IN
SELECT
FE
GND
10p
B
0.01µ
FM IF
IN
VIN 3
FM 10.7MHz
IB
12
TUNE
IND
25
18p
FM RF
IN
2200p
150µH
VIN 1
FM 100MHz
0.01µ
AM RF
IN
10p
43p
150
100
VIN 2
AM 1660kHz
330
S6
A
2k
B
S5
30p
VA
VS
CXA1538M/N/S
—7—
1
PLL
LPF
28
R3
10k
27
VCO
26
C12
1µ
∗C13
0.022µ
2
R5
2.2k
∗C14
0.022µ
3
4
25
C8
3.3µ
R9
100
24
C1
7p
L1
∗R6
3.3k
5
VCC=3V
∗R7
3.3k
6
Lch
OUT
AFC
23
C7
3p
FM
OSC
22
C2
2.0p
L2
21
REG
C3
18p
20
FM
RF
L3
19
18
17
BPF
16
AM RF FM RF GND FM/AM
IN
IN
FE OUT
L4
C4
4PF
7
C15
100µ
8
C16
33µ
9
C17
1µ
10
C18
4.7µ
11
R8
2.2k
C19
0.01µ
12
C20
0.01µ
CF2
R10
330
14
15
BPF
CF1
CF2
CF3
IFT
R1
100k
CF1
: FM BAND PASS FILTER
: AM 455kHz CF
: FM 10.7MHz CF
: FM DISCRIMINATOR
: AM 455kHz IFT
IFT
Application circuits shown are typical examples illustrating the operation of the devices. Sony cannot assume responsibility for
any problems arising out of the use of these circuits or for any infringement of third party patent and other right due to same.
13
S1
R2
2.2k
RIPPLE AGC/ AGC/
TUNE FM IF AM IF BAND
IN
IN SELECT
VCC FILTER AFC 1 AFC 2 GND IND
FM MUTE AM
DISCRI
OSC
RV
22k
CF3
PILOT PILOT ST IND/
DET DET VCO Rch
LPF1 LPF2 CHECK OUT
MPX
REG
Capacitor unit : F
L ch OUT
R ch OUT
C10
0.47µ
29
PLL
LPF
30
GND
C9
10µ
C5
C6
0.001µ 10µ
Note) This circuit is an application example and is not guaranteed for all applications.
For C, R (C13, C14, R6, R7) marked∗, refer to “2. MPX circuit” of “Notes on Usage.”
C11
4.7µ
R4
2.2k
Application Circuit
CXA1538M/N/S
CXA1538M/N/S
FM I/O characteristics
0
SIGNAL (MONO)
SIGNAL (STEREO)
Separation/response (dB)
–10
VCC
FREO
MODE
DEV
–20
3V
98MHz
400Hz
22.5kHz
–40
L→R
R→L
SEPARATION
Distortion THD1 (%)
–30
5
4
–50
3
NOISE(MONO)
–60
NOISE(STEREO) (WITH LPF)
2
1
DISTORTION(MONO)
10
20
30
40
50
60
70
80
90
100
110
Input signal level (dBµV)
AM I/O characteristics
0
SIGNAL
VCC
3V
FREO 1000kHz
MOD 400Hz, 30%
–20
–30
–40
5
NOISE
4
–50
3
2
DISTORTION
1
–60
10
20
30
40
50
60
70
80
Input signal level (dBm)
90
100
Distortion THD2 (%)
Response (dB)
–10
110
79
VCO - free-running frequency (kHz)
Separation (dB)
45
40
Vin3=90dBµV 10.7MHz
Vin3=90dBµV 10.7MHz CW
78
77
76
75
fmod = 1kHz 22.5kHz dev
Pilot ON
73
74
75
76
77
78
79
0
VCO - free-running frequency (kHz)
20
40
60
Ta - Ambient temperarure (°C)
—8—
80
CXA1538M/N/S
Coil data
AM OSC
S
Core diameter ø 0.06 mm 2 UEW
3
4
2
5
f (kHz)
1
6
796
L (µH)
1 to 3
270
QO
1 to 3
125
Number of widings (t)
1 to 3
4 to 6
107
29
Equivalent to L-5K7H5 R12-1684X, Mitsumi Electric Co., Ltd. or
7TRS-8441 TOKO Co., Ltd.
FM RF
φ 5mm
φ 6mm3.5t
AM IFT
3
S
Core diameter ø 0.07 mm UEW
4
2
5
1
6
CO (pF)
1 to 3
180
QO
1 to 3
90
Number of widings (t)
1 to 2
2 to 3
4 to 6
111
35
7
Equivalent to 21K7H5 R12-8558A, Mitsumi Electric Co., Ltd. or
7MC-7789N TOKO Co., Ltd.
FM OSC
φ 4mm
φ 0.6mm3.5t
FM Discriminator
Core diameter ø 0.1 mm 2 UEW
3
4
2
5
1
6
CO (pF)
1 to 3
82
QO
1 to 3
95
Number of widings (t)
1 to 3
111
Equivalent to 119ASC-12200Z, TOKO Co., Ltd.
AM Bar Antenna
f (kHz)
796
PRIMARY
L (µH)
650
Primary
91 t
Secondary
20 t
SECONDARY
BPF
CF1
CF2
CF3
VC
VC (Rear Mount)
PFWE8
(88 to 108 MHz)
Soshin Electric Co., Ltd.
SFU-455B
SFE10.7MA5
CDA10.7MG1
PVC2LXT16L
HU22124N700
PVC2LXT16B
Murata Mfg. Co., Ltd. or BFCFL-455
Murata Mfg. Co., Ltd.
Murata Mfg. Co., Ltd.
Mitsumi Electric Co., Ltd.
TOKO Co., Ltd.
Mitsumi Electric Co., Ltd.
—9—
TOKO Co., Ltd.
CXA1538M/N/S
Notes on Usage
1. VCO free run frequency adjustment method
As this IC has built-in oscillation capacitance, the oscillation frequency can be controlled with an external
resistor.
27
28
10k
Capacitor for decoupling
22k
1) VCO Adjustment Method
Pin 4 is the stereo indicator and VCO check pin. Therefore, in stereo mode (when stereo indicator drive
Tr Q2 is switched on), pin 4 voltage lowers down, Q1 is cut off and VCO oscillation waveform can not be
seen. In AM mode as well, the oscillation waveform can not be seen as VCO turns off.
Adjust the free run frequency at 76 kHz ±50 Hz.
VCC
33k
4
Q1
about 180mVp-p
Q2
In this IC, tuner and MPX sections are directly connected. Therefore, free run frequency is not stable, being
affected by noise except in reception mode. For free run adjustment, input signals from either RF or IF.
(Input signal should be RF [Tuning frequency] or fo of the discriminator using IF (10.7 MHz) and input
more than 60 dBµ.)
2) How to Deal with pin 4 After Adjustment.
With the use of a stereo indicator.
When VCC is 3 V or more, insert a bypass resistance
R to prevent LED malfunction.
VCC=3V
2.2k
2.2k
4
4
R
Without the use of a stereo indicator.
4
VCC>3V
OPEN
Turn pin 4 to open or connect to GND.
4
3) Control Resistor of VCO Oscillation Frequency
For the VCO control resistor of this iC, a carbon film resistor suffices.
For easier adjustment of temperature characteristics and VCO free run frequency, the following
combination is recommended.
27
28
10k
22k
—10—
CXA1538M/N/S
2. MPX circuit
1) MPX load resistance
When power supply voltage is over 3 V, change the MPX load resistor R6, R7 from 3.3 kΩ to 6.8 kΩ.
In this case, the output level is increased by about 6 dB.
2) Time constant of de-emphasis
Refer to the following table as the time constant is determined at C13, C14, R6 and R7.
3.3 kΩ
0.015 µF
0.022 µF
50 µs
75 µs
6.8 kΩ
0.0082 µF
0.012 µF
R6, R7
C13, C14
3. AFC circuit
1) This IC has a built-in variable capacitances.
Change to the following circuit when designing J band, because the standard circuit is for W band.
3pF
23
22
9
10
150k
4.7µ
1µ
1µ
2) AFC pull-in range is expanded by increasing the capacitance of standard circuit C7 3 pF.
Adjust the value of capacitance according to the set specification.
4. Auto blend circuit
This IC has a built-in auto blend circuit and a MONO switch is not required as a rule. This circuit controls
the separation in proportion to the signal level and reduces noise automatically for stereo reception below
the mid electric field when the electric field strength reaches lower than about 40 dBµ. When the electric
field strength turns below 10 to 15 dBµ, MONO operation is automatically activated.
To switch MONO mode on externally, ground pin 3 with 33 kΩ.
2
3
33k
MONO
SW
—11—
CXA1538M/N/S
5. FM discriminator
For FM detection, the quadrature detection system is adopted. As a phase shifter, a ceramic resonator (CF
3 discriminator) applies to achieve adjustment-free detection. Though the sensitivity and selectability will be
slightly affected, the discriminator can be replaced by a coil as shown below. Combining CF2 (FMIF) and
CF3 (PM discriminator) poses problems with the distortion factor when deviation with the IF band central
frequency fo occurs. To this effect, use pairs of the same rank as indicated in the chart.
A
B
C
D
E
Red
Blue
Orange
Black
White
fO of CF2 and CF3
10.70 MHz
10.67 MHz
10.73 MHz
10.64 MHz
10.76 MHz
26
22pF
DISCRI
COIL
6. FM muting circuit
This IC has a built-in soft muting circuit.
As shown in the following I/O characteristics diagram, 23 dB (Typ.) muting is applied and noise level
reduced during weak electric field and out of tune instances.
RESPONSE (dB)
Conventional IC
3
S+N
IC with built-in soft MUTE
–23
N
INPUT LEVEL (dBµ)
7. Notes on patterns
1) Positions of FM ANT and OSC coils
Locate those at right angles to each others to avoid inductance M through coupling. Further, insert a pin
21 pattern between patterns of pins 22, 20 and coils.
2) Tuning circuit
As the capacitances C1 to C4, L2 and L3 are the constants on the standard circuit board, check the
constants when a new circuit board is used.
3) Grounding pins
Pin 17 is a grounding pin for AM, FM and FE ; pin 11 for IF ; and pin 30 for MPX. Use as thick as
possible a pattern since the grounding between ANT IN, BPF and pin 17 significantly stability, NF and
characteristics affects.
BPF
18
17
ANT
IN
16
4) Ground bypass capacitors C5 (0.001 µF) and C6 (10 µF) connected to pin 21 as close as possible to pin
17.
—12—
CXA1538M/N/S
CXA1538M
CXA1538S
—13—
CXA1538M/N/S
Package Outline
Unit : mm
CXA1538M
30PIN SOP(PLASTIC)
+ 0.4
2.3 – 0.15
+ 0.4
18.8 – 0.1
0.1
30
+ 0.2
0.1 – 0.05
(9.3)
A
0.5 ± 0.2
10.3 ± 0.4
+ 0.3
7.6 – 0.1
16
15
1
+ 0.1
0.2 – 0.05
1.27
0.45 ± 0.1
0.2
M
0° to 10°
DETAIL A
PACKAGE STRUCTURE
PACKAGE MATERIAL
EPOXY RESIN
SONY CODE
SOP-30P-L03
LEAD TREATMENT
SOLDER PLATING
EIAJ CODE
SOP030-P-0375
LEAD MATERIAL
COPPER ALLOY
PACKAGE MASS
0.7g
JEDEC CODE
CXA1538N
30PIN SSOP (PLASTIC)
+ 0.2
1.25 – 0.1
∗9.7 ± 0.1
1
+ 0.1
0.22 – 0.05
7.6 ± 0.2
16
∗5.6 ± 0.1
30
0.10
A
15
+ 0.05
0.15 – 0.02
0.65
0.13 M
0.5 ± 0.2
0.1 ± 0.1
0° to 10°
NOTE: Dimension “∗” does not include mold protrusion.
DETAIL A
PACKAGE STRUCTURE
PACKAGE MATERIAL
EPOXY RESIN
SONY CODE
SSOP-30P-L01
LEAD TREATMENT
SOLDER/PALLADIUM
PLATING
EIAJ CODE
SSOP030-P-0056
LEAD MATERIAL
42/COPPER ALLOY
PACKAGE MASS
0.1g
JEDEC CODE
NOTE : PALLADIUM PLATING
This product uses S-PdPPF (Sony Spec.-Palladium Pre-Plated Lead Frame).
—14—
CXA1538M/N/S
CXA1538S
+ 0.1
05
0.25 – 0.
30PIN SDIP (PLASTIC)
+ 0.4
26.9 – 0.1
30
+ 0.3
8.5 – 0.1
10.16
16
0° to 15°
15
1
+ 0.4
3.7 – 0.1
0.5 MIN
1.778
0.5 ± 0.1
3.0 MIN
Two kinds of package surface:
1.All mat surface type.
2.All mirror surface type.
0.9 ± 0.15
PACKAGE STRUCTURE
MOLDING COMPOUND
EPOXY RESIN
SONY CODE
SDIP-30P-01
LEAD TREATMENT
SOLDER/PALLADIUM
PLATING
EIAJ CODE
SDIP030-P-0400
LEAD MATERIAL
COPPER ALLOY
PACKAGE MASS
1.8g
JEDEC CODE
NOTE : PALLADIUM PLATING
This product uses S-PdPPF (Sony Spec.-Palladium Pre-Plated Lead Frame).
—15—