AM Tuner System for

Car Radios and Home Stereos

Overview

The LA1135 is a high-performance AM electronic tuner IC that
is greatly improved in cross modulation characteristics. It is
especially suited for use in car radio and home stereo (antenna:
loop) applications.

Functions

MIX

OSC (with ALC)

IF amplifier

Detector

AGC (normal)

RF wide-band AGC

Auto search stop signal (signal meter output)

Local oscillation buffer output

Others

Features

Excellent cross modulation characteristics: Meets the
requirements for preventing not only adjacent-channel
interference but also interference caused by all channels
within broadcast band.

Narrow-band signal meter output: Usable as auto search stop
signal. Has linearity up to 80 dBµ.

Local oscillation buffer output: Facilitates designing of
electronic tuner system, frequency display, etc.

OSC (with ALC): Improves tracking error because
oscillation output is stabilized at a low level (380 mVrms)
for varactor diode.

MIX: Double-balanced differential MIX meeting the
requirements for preventing spurious interference, IF
interference.

Good characteristics at high input: 130 dBµ input
f

= 400 Hz 80% mod THD = 0.4% typ

Low noise: Good S/N at medium input (56 dB typ)

Usable sensitivity: (S/N = 20 dB input): 25 dBµ (2SK315
I

DSS

= 11mA)

variation compensation: Less variation in gain,

distortion: 8 to 12 V

Reduced pop noise: Capable of reducing pop noise at the
time of V

ON, mode select by adjusting AGC time

constant.

Package Dimensions

unit : mm

3021B-DIP20S

[LA1135]

SANYO : DIP20S

unit : mm

3036B-MFP20

[LA1135M]

SANYO: MFP20

Ordering number: EN1272E

Monolithic Linear IC

LA1135, 1135M

SANYO Electric Co.,Ltd. Semiconductor Bussiness Headquarters

TOKYO OFFICE Tokyo Bldg., 1-10, 1 Chome, Ueno, Taito-ku, TOKYO, 110 JAPAN

93097HA(II)/D0994JN/O217KI/4034KI.TS(KOTO) No.1272-1/18

Specifications

Maximum Ratings

at Ta = 25°C

Parameter

Symbol

Conditions

Ratings

Unit

Maximum supply voltage

max

Pins 8, 14

Output voltage

Pins 7, 10

Input voltage

Pin 6

5.6

Current drain

Pins 7 + 8 + 10 + 14

Flow-out current

Pin 18

Pin 20

Allowable power
dissipation

Pd max

LA1135

730

LA1135M Ta

60°C, with PCB

660

Operating temperature

Topr

LA1135

20 to +70

°C

LA1135M

40 to +80

°C

Storage temperature

Tstg

40 to +125

°C

Operating Conditions

at Ta = 25°C

Parameter

Symbol

Conditions

Ratings

Unit

Recommended supply
voltage

Operating supply voltage
range

7.5 to 12

Operating Characteristics

at Ta = 25°C, V

= 8 V, f

= 1 MHz, f

= 400 Hz, See specified Test

Circuit.

Parameter

Symbol

Conditions

min

typ

max

Unit

Current drain

Quiescent

13.5

22.5

32.5

130 dBµ input

20.0

30.0

41.0

Detection output

16 dBµ input, 30% mod

29.0

25.0

21.0

dBm

74 dBµ input, 30% mod

15.0

12.0

9.0

dBm

Signal-to-noise ratio

S/N

74 dBµ input, 30% mod

51.0

56.0

Total harmonic distortion

THD1

74 dBµ input, 30% mod

0.3

1.0

THD2

74 dBµ input, 80% mod

0.3

1.0

THD3

130 dBµ input, 80% mod

0.4

2.0

Signal meter output

Quiescent

0.3

130 dBµ input

3.5

5.0

7.5

Input at signal meter output 1 V

= 1 V

18.0

24.0

30.0

dBµ

Local oscillation buffer output

OSC

BUF

320

380

mVrms

LA1135, 1135M

No. 1272-2/18

Reference Characteristics

Parameter

Symbol

Conditions

typ

Unit

Usable sensitivity

Q.S.

Input at S/N = 20 dB
(2SK315 I

DDS

= 11 mA)

25.0

dBµ

Wide-band AGC
ON-state input

Reception 1.0 MHz quiescent
Interference 1.4 MHz non-mod
at input for AMT.D. ON

82.0

dBµ

Detection output variation

Input 74 dBµ

130 dBµ

0.2

Local oscillation variation
within broadcast band

OSC

L V

OSC

mVrms

Signal meter band

SM-BW1

74 dBµ input, frequency at
which output is reduced to 1/2

1.5

kHz

SM-BW2

74 dBµ input, frequency at
which output is reduced to 1/10

4.5/+7

kHz

Selectivity

30 % mod

10 kHz

IF interference

IF. R.

= 600 kHz

77.5

Image frequency
interference

IM. R.

= 1400 kHz

52.0

(63.0)

Note:

*: Wide-band AGC OFF
( ): See circuit on page 7.

Equivalent Circuit Block Diagram

Allowable

power

dissipation,

max

Ambient temperature, Ta °C

with 54

1.7 mm

PCB

Pd max Ta

LA1135, 1135M

No. 1272-3/18

Test Circuit 1

= 8 V, f

= 1 MHz, f

= 400 Hz

Sample Printed Circuit Pattern

DC voltmeter

Distortion

meter

Valve

voltmeter

HF valve voltmeter

Varactor diode

SVC321

(Sanyo)

Narrow-band filter

BFU450CN

(Murata)

Coil

YT-30020

(Mitsumi)

YT-30018

(Mitsumi)

CFMA-027

(Toko)

YT-30007

(Mitsumi)

YT-30008

(Mitsumi)

Unit (resistance:

, capacitance: F)

Cu-foiled area 105

120 mm

LA1135, 1135M

No. 1272-4/18

Proper cares in using IC

Bias condition: RF V

% IF V

Avoid coupling between the antenna tuning circuit and the local oscillation.

Connect detection capacitor C15 across pins 13 (output) and 14 (V

) so that no leakage of the IF signal to the GND line

occurs. (If connected to GND, the tweet and the usable sensitivity may get worse.) Radiation from C15 may cause harmonics
in the IF signal to return to the RF stage, thereby leading to more tweet interference. So, connect C15 as close to pins 13, 14
as possible. Consider the direction of the capacitor and separate it from the ANT circuit.

For R9, use a semifixed resistor with V

considered.

When designing the coils, consider the following conditions.
Shown below is the input level at each pin at which the detection output at f

= 400 Hz 30% mod becomes 25 dB.

ANT

MIX

Det

16.0

28.0

45.0

61.0

(dBµ)

How to apply input to each stage

ANT damping
To make the ANT damping constant within the receiving band, change the application circuit as shown below.

Measures

Replace R1 with C

(2000 pF to 3000 pF or thereabouts)

Relocate L2.

Damping (600 kHz to 1400 kHz)

Old circuit 15 dB
New circuit 4 dB

ANT stage

MIX stage

ANT input

IF stage

Det stage

Unit (resistance:

, capacitance: F)

Old circuit

New circuit

Double tuning

LA1135, 1135M

No. 1272-6/18

Meaning of L2
If the RF stage is double-tunned, the difference in sensitivity within the RF band almost disappears, but an antireasonance
point of approximately 20 MHz appears, thereby leading to worse spurious characteristics. So, L2 is used to remove the SW
band.

Wide-band AGC
This IC contains 2-channel wide-band AGC. Pin 6 detects an undesired signal within the RF band and wide-band AGC is
applied. This detection sensitivity is determined inside the IC. Pin 2 detects an undesired signal outside the RF band. This
detection sensitivity is determined by R3. When 1 mVrms (f = 1 MHz) signal is applied to pin 2, AGC operates.

Measures against suppression of sensitivity
In the AGC circuit of the test circuit the presence of an undesired signal of high strength within the receiving band may cause
the desired signal to be suppressed when the desired signal is low or medium in strength. Shown below is the circuit
configuration where the necessary measures are taken against this suppression.

10. Transient response of S meter output at search, stop mode

The circuit configuration shown below is available to stabilize the transient response of the S meter output at the search, stop
mode.

11. When using LW (approximately 50°C or greater), additionally connect a resistor of 27 k

across pins 18 and 19 against

increase in local oscillation level. When using MW, no additional resistor is required.

12. Improvement in image frequency interference

Change the RF double-tuning coil as follows, and the image frequency interference becomes 63 dB at f

= 1400 kHz.

(Q of the tuning circuit must not be decreased with resistor 100 k

Continued on next page.

S meter output

Wide-band

AGC input

Wide-band

AGC

circuit

Circuit added

Sample constants

= 4.3 k

= 3.0 k

-130 = 5.0 V)

ANT

damping

driver circuit

ANT

damping pin

Signal during searching from PLL

Unit (resistance:

)

LA1135, 1135M

No. 1272-7/18

Continued from preceding page.

Unit (resistance:

, capacitance: F)

Specification for coil

YT-30202(Mitsumi)

1-3

84T

4-6

17T

13. The variations (especially in case of small coupling coefficient) in the oscilation coil may cause a parasitic oscillation of

approximately 100 MHz to occur at the local oscillation buffer output (pin 20) at low temperatures. In this case, connect a
capacitor of 30 pF or greater across pin 20 and GND. (When the oscillation coil is used with no tap, no problem arises.)

14. The recommended double-tuning circuit has a loose coupling at 2T. Therefore, the change in the total number of turns may

affect the coupling coefficient subtly, causing a tight coupling and making the selectivity characteristic double-humped.
Especially for a receiving band of 1400 kHz or more, the tracking method may affect the band characteristic of sensitivity
and the cross modulation characteristic considerably. When making a design, check to see if critical coupling occurs or not.

15. Sensitivity difference at 600 kHz or less

In the application circuit configuration shown below, the bypass capacitor in the position where the tuning voltage is applied
and coupling L for double-tuning may cause an antiresonance point of 400 kHz to 600 kHz depending on the variations in
the coil, varactor diode, etc. The value of the bypass must be 0.047 µF or greater. The recommended value is 0.1 µF.

Usable

sensitivity

Maximum

sensitivity

dBµ

Image

frequency

interference

Wide-band AGC OFF

Tracking at
each point

Usable sensitivity S/N 20 dB

Maximum sensitivity at 25 dB output

Receiving frequency, f

kHz

2157-2239-649 (Sumida)
7BRS-9286A (Toko)

Unit (resistance:

, capacitance: F)

LA1135, 1135M

No. 1272-8/18

16. Measure against suppression of sensitivity in the presence of an undesired signal of high strength

(Sample application where two PIN diodes are used in the antenna damping circuit)
The LA1135 contains the wide-band AGC circuit (wide-band AGC with pin 2 input) against cross modulation which occurs
because an undesired signal of high strength distorts the FET input. The AGC = ON level depends on the value of external
resistor R3 as shown below.

When a nonlinear element, such as transistor, is used for antenna damping, cross modulation which occurs when the transistor is
turned ON is as shown below.

The dynamic range of the FET input covers up to approximately 110 dBµ of antenna input, but the AGC-ON level must be set
lower because of the bad effect shown above.
Therefore, there are some cases where it is difficult to receive a desired signal of low strength in the presence of an an undesired
signal of high strength. To solve this problem, a sample application circuit where two PIN diodes with good linearity are used for
antenna damping and its cross modulation characteristic are shown below.

Sample Application Circuit where two PIN diodes are used for ANT damping

.B.AGC-ON

level

dBµ

Test conditions

Double-tuning

ANT input level
at which ANTD is turned ON when
f

= 1.4 MHz is inputed at f

= 1 MHz

Resistor value, R

Cross modulation characteristic which is caused
by the ANT Tr when the
LA1135 wide-band
AGC-ON level (with
pin 2 input) is varied

Unit (resistence:

, capacitance: F)

Output

Cross Modulation Characteristics

Desired:1.0 MHz 400 Hz 30% mod 74 dBµ
Undesired: 1.4 MHz non-mod

Wide-band AGC (pin 2 input)75

Desired: 1.0 MHz 400 Hz

non-mod 74 dBµ

Undesired: 1.4 MHz 1 kHz

80% mod

Cross modulation which occurs when the
transistor for ANT damping is turned ON

Undesired input dBµ

Double-
tuning

Equivalent capacitance available
(Capacitance is desirable because
of a slight change in ANT damping
in the band)

(Approximately 3000 pF)

Unit (resistance:

, capacitance: F)

Double-
tuning

LA1135, 1135M

No. 1272-9/18

17. For details of the LA1135 wide-band AGC, refer to Technical Data No.79.

External Parts

(1) RF double-tuning coil

Primary

YT-30020 (Mitsumi)

2157-2239-518A (Sumida)

7BRS-8934A (Toko)

37T

40T

35T

82T

90T

75T

Secondary

YT-30018 (Mitsumi)

2157-2239-517A (Sumida)

7BRS-8932A (Toko)

15T

16T

14T

82T

90T

75T

(2) OSC coil

YT-30008 (Mitsumi)

2157-2239-516 (Sumida)

7BR-5941Y (Toko)

29T

34T

29T

35T

29T

(3) IFT (I)

Output

Cross Modulation Characteristics

Desired: 1.0 MHz fm = 400 Hz 30% mod

Undesired: 1.4 MHz non-mod

Application where two PIN diodes are used for ANT damping

Desired: 1.0 MHz non-mod

Undesired: 1.4 MHz f

m = 1 kHz 80% mod

Pin 2 input W.B.AGC
External pickup R3 = 5

Undesired input dBµ

CFMA-027 (Toko)

69T

77T

14T

Center frequency 450 kHz
Qu = 115

20%

Tuning capacitance 180 pF

YT-30042 (Mitsumi)

+SFP450H (Murata)

49T

27T

103T

Center frequency 450 kHz
Qu = 45

20%

Tuning capacitance 180 pF

High selectivity type

LA1135, 1135M

No. 1272-10/18

(4) IFT (II)

YT-30007 (Mitsumi)

4140-1289-164 (Sumida)

7MC-6272N (Toko)

115T

111T

110T

37T

36T

Center frequency 455 kHz,
Qu = 110%
Tuning capacitance 180 pF

Center frequency 455 kHz
Qu = 110%
Tuning capacitance 180 pF

Center frequency 455 kHz,
Qu = 110%
Tuning capacitance 180 pF

(5) Varactor diode: SVC321

(6) FET at RF stage:

2SK315 F, G
2SK427 T, U

(7) Transistor for AGC

FET AGC: 2SC536 F, G
ANT damping: 2SC930 E

(8) Narrow-band resonator BFU450CN Murata

Band Characteristics

Tracking at each point

IF interference

Wide-band AGC cutoff

Image frequency
interference

Input at 20 dB S/N

Input at 25 dBm output

Receiving frequency, f

kHz

T
otal

harmonic

distortion,

THD

interference,

image

frequency

interference,

S/N

Output

dBm

Overall Characteristics

Detection output at 30% mod

Input voltage dBµ

M.S.,

Q.S.

dBµ

Output

dBµ

Tweet Input Characteristics

Signal characteristic
f

= 900 kHz f

= 400 Hz 30% mod

Complete tuning
(Beat max. at
900 kHz tuning)

Complete tuning
(Zero beat)

ANT input dBµ

LA1135, 1135M

No. 1272-11/18

Detection

output,

O-74

dBm

Detuning Characteristics

Vary V

so that

tweet output is
maximized at each
point.

Frequency deviation,

f kHz

Output

dBµ

Spurious Characteristics

Difference in input at 25 dBm output

Receiving frequency, f

otal

harmonic

distortion,

THD

Detection output 30% mod

Output

dBµ

Output

rms

Detection Output, THD Modulation Characteristics

Input: 74 dBµ

Detection output

Distortion

Modulation %

THD f

Selectivity

Selectivity Characteristics

W.B.AGC
operation

Difference in
input at 25 dBm
output

Frequency deviation,

f kHz

Output

dBm

Detuning Characteristics

Detection output 30% mod

Noise

Frequency deviation,

f kHz

meter

output,

Detuning Characteristics

Using narrow-band filter

Frequency deviation,

f kHz

LA1135, 1135M

No. 1272-12/18

Output,

dBm

Detection output-Input: 74 dBµ

Detection output

Supply voltage, V

otal

harmonic

distortion,

THD

meter

output,

Input: 130 dBµ

Using narrow-band filter

Supply voltage, V

, THD V

 V

Current

drain,

Quiescent

Supply voltage, V

Frequency

deviation,

kHz

OSC coil 1/2 tap

Supply voltage, V

 V

f V

OSC coil 1/2 tap

Supply voltage, V

OSC

 V

OSC

LA1135, 1135M

No. 1272-13/18

Cross Modulation Characteristics Testing Method

Current

drain,

ANT

input

dBµ

.B.AGC

input

dBµ

meter

output,

SM-130

SM-47

Temperature Characteristics

= 1 V

input

Ambient temperature, Ta °C

input

dBµ

otal

harmonic

distortion,

THD

Usable

sensitivity

Q.S.

dBµ

Temperature Characteristics

Usable sensitivity (Input at 20 dB S/N)

Ambient temperature, Ta °C

Maximum

sensitivity

dBµ

O-74

dBm

S/N

OSC

rms

AGC-0

2-signal pad JIS Dummy ANT

Unit (resistance:

, capacitance: F)

Output

Desired signal ANT input

Solid line ---- Interference
Dotted line ---- No interference

A: Desired signal 80 dBµ 400 Hz 30% mod.

The strength of an undesired signal
(non-mod) causes the desired signal to
be suppressed.

B: Desired signal 80 dBµ non-mod.

The strength of an undesired signal (400
Hz 80% mod) causes interference to
occur.

LA1135, 1135M

No. 1272-14/18

Output

dBµ

Cross Modulation Characteristics

Desired 1.0 MHz

400 Hz
30% mod

Undesired 1.4 MHz

non mod

Desired input 80 dBµ

Desired

input

dBµ

Desired 1.0 MHz

non mod

Undesired

1.4 MHz
400 Hz
80% mod

Undesired input dBµ

Output

dBµ

Cross Modulation Characteristics

Desired 1.4 MHz

400 Hz
30% mod

Undesired 1.44 MHz

non mod

Desired input 90 dBµ

Desired input 40 dBµ

Desired 1.4 MHz

non mod

Undesired

1.44 MHz
400 Hz
80% mod

Undesired input dBµ

LA1135, 1135M

No. 1272-15/18

Specification for LA1135 loop ANT

(1) Features of specification for LA1135 loop ANT

1) Excellent high-input characteristic

The antena damping circuit prevents the antena circuit from being magnetic-saturated, which results in worsened
characteristic, at a high input.

2) Excellent cross modulation characteristic

(2) Application circuit

(3) Circuit configuration and connection

3-1 Circuit configuration

3-2 Connection (bottom view)

DC voltmeter

Distortion meter

Valve voltmeter

HF valve voltmeter

Unit (resistance:

, capacitance: F)

Unit (resistance:

, capacitance: F)

LA1135, 1135M

No. 1272-16/18

3-3 Pin name

Pin No.

Pin Name

Loop ANT

RF AMP GND side

Pin No.

Pin Name

Local OSC

RF output

Tuning voltage

Local OSC

(4) Specification

Receiving frequency band

MW BAND

Tuning voltage

1 to 9 V

Loop ANT

42579719100 (LA-1500), 4257976000 (LA-100A) (Korin)

LA1135

Output

dBµ

Overall Characteristics

Detection output at 30% mod

Input voltage dBµ

Output

dBµ

Band Characteristics

IF interference

Image frequency interference

S/N 20 dB sensitivity

Input at V

= 25 dBm

Receiving frequency kHz

Output

Detection Output, THD Modulation Degree

Detection output V

Modulation degree %

OSC

Input 74 dBµ

LA1135, 1135M

No. 1272-17/18

No products described or contained herein are intended for use in surgical implants, life-support systems,
aerospace equipment, nuclear power control systems, vehicles, disaster/crime-prevention equipment and the like,
the failure of which may directly or indirectly cause injury, death or property loss.

Anyone purchasing any products described or contained herein for an above-mentioned use shall:

Accept full responsibility and indemnify and defend SANYO ELECTRIC CO., LTD., its affiliates, subsidiaries and
distributors and all their officers and employees, jointly and severally, against any and all claims and litigation
and all damages, cost and expenses associated with such use:

Not impose any responsibility for any fault or negligence which may be cited in any such claim or litigation on
SANYO ELECTRIC CO., LTD., its affiliates, subsidiaries and distributors or any of their officers and employees
jointly or severally.

Information (including circuit diagrams and circuit parameters) herein is for example only; it is not guaranteed for
volume production. SANYO believes information herein is accurate and reliable, but no guarantees are made or
implied regarding its use or any infringements of intellectual property rights or other rights of third parties.

This catalog provides information as of September, 1997. Specifications and information herein are subject to change without notice.

Output

dBµ

Detuning Characteristics

Detection output

Input

dBµ

Input

dBµ

Frequency deviation kHz

Selectivity

Selectivity Characteristics

Frequency deviation kHz

Supply voltage, V

OSC

OSC

 V

Frequency

deviation,

kHz

Supply voltage, V

f V

LA1135, 1135M

No. 1272-18/18

Ð­Ð»ÐµÐºÑ‚Ñ€Ð¾Ð½Ð½Ñ‹Ð¹ ÐºÐ¾Ð¼Ð¿Ð¾Ð½ÐµÐ½Ñ‚: LA1135M

ÐÐ»ÐµÐºÑ‚Ñ€Ð¾Ð½Ð½Ñ‹Ð¹ ÐºÐ¾Ð¼Ð¿Ð¾Ð½ÐµÐ½Ñ‚: LA1135M