LA1805

Ordering number : EN2887B

AM/FM-IF/MPX Tuner System

for Radio-Casette Recorders, Music Centers

Monolithic Linear IC

SANYO Electric Co.,Ltd. Semiconductor Bussiness Headquarters

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

12798HA (KT)/D0994JN/4030MO/N148YT, TS No.2887-1/13

Overview

The LA1805 is a characteristics-improved version of the

LA1810, with the same pin assignment and package as

those of the LA1810. Improvements are made on the

following point :

· Separation (35dB

48dB) and its dependence on free-

running frequency (Sep f

Characteristic on page 4).

· FM main distortion (0.8%

0.45%).

· AM detection output (approximately 5dB increased).

The constants on five external parts are changed as shown

on page 10.

Functions

· FM-IF : IF amp, quadrature detector, soft muting, tuning

indicator.

· MPX : PLL stereo decoder, stereo indicator, forced

monaural, VCO stop.

· AM : RF amp, MIX, OSC (with ALC), IF amp, detector,

AGC, tuning indicator.

Features

· FM/AM/MPX functions contained on a single chip.

· Minimum number of external parts required.

· On-chip FM muting function.

· High sensitivity.

· Less carrier leak of MPX.

Specifications
Maximum Ratings

at Ta=25°C, See specified Test Circuit.

Parameter

Symbol

Conditions

Ratings

Unit

Maximum supply voltage

max

Pins 3, 7, 8, 11, 20, 21

Maximum supply current

max

Pins 3+20+21

Flow-in current

LED

Pins 7, 8

(Indicator drive current)

Flow-out current

Pin 23

0.1

Allowable power dissipation

Pd max

70°C

500

Operating temperature

Topr

20 to +70

°C

Storage temperature

Tstg

40 to +125

°C

Package Dimensions

unit : mm

3067-DIP24S

[LA1805]

SANYO : DIP24S

0.48

3.25

3.3

3.9max

0.51min

21.2

0.81

1.78

0.25

7.62

6.4

0.95

LA1805

No.2887-2/13

Operating Conditions

at Ta=25°C

Parameter

Symbol

Conditions

Ratings

Unit

Recommended operating voltage V

4.5

Operating voltage range

3.0 to 8.0

Note : The FM output level forms an N curve (LA1805) and an S curve (LA1806).

LA1805 : N curve (for US band)
LA1806 : S curve (for Japanese band). Your desired output level can be set by varying the output resistance.

Operating Characteristics

at Ta=25°C, V

=4.5V, See Test Circuit

Parameter

Symbol

Conditions

Ratings

min

typ

max

Unit

[FM characteristics (Mono) : f

=10.7MHz, f

=1kHz]

Quiescent current

Icco

No input

3dB sensitivity

3dBL.S.

Referenced to V

=100dBµ,

dBµ

100%, down 3dB

Demodulation output

=100dBµ, 100% mod.

140

205

280

Channel balance

C.B.

=100dBµ, 100% mod.

1.5

Total harmonic distortion

THD

=100dBµ, 100% mod.

0.45

1.2

Signal to noise ratio

S/N

=100dBµ, 100% mod.

LED ON sensitivity

LED

=1mA

dBµ

[FM characteristics (Stereo) : f

=10.7MHz, f

=1kHz, L+R=90%, pilot=10%, V

=100dBµ]

Separation

Sep

Stereo distortion

THD (Main)

0.45

1.2

LED ON level

LED

-on

2.4

3.9

5.4

LED OFF level

LED

-off

2.7

[AM characteristics : f

=1000kHz, f

=1kHz]

Quiescent current

Icco

No input

9.5

14.5

Demodulation output

=23dBµ, 30% mod.

=80dBµ, 30% mod.

113

173

Signal to noise ratio

S/N1

=23dBµ, 30% mod.

S/N2

=80dBµ, 30% mod.

Total harmonic distortion

THD1

=80dBµ, 30% mod.

0.45

1.2

THD2

=100dBµ, 30% mod.

0.6

1.5

LED on sensitivity

LED

=1mA

dBµ

Note : Be fully careful of dielectric breakdown.

Equivalent Circuit Block Diagram

LA1805

No.2887-3/13

Test Circuit

Polystyrene film capacitor
Differs from the application circuit
where a front end is used.
(See Sample Application Circuit
on page 10.)

How to use the LA1805

1. Forced monaural mode.

Figures 1 and 2 show how to cause the forced monaural mode to be entered.

(1) Connect pin 14 to V

through a resistor of 100k

. (Turn ON the SW1 in Figure 1.)

(2) Connect pin 15 to GND through a resistor of 47k

. (Turn ON the SW2 in Figure 2.)

Figure 1 Forced Monaural Mode Setting Method

Figure 2 Forced Monaural Mode Setting Method

Unit (resistance :

, capacitance : F)

Either above-mentioned (1) or (2) causes the forced

monaural mode to be entered. In this case, the VCO

does not stop operating. If the resistance of R1 and

R2 are decreased, internal bias will vary when the S1

or S2 is turned ON. This data is shown in Figure 3.

Forced Monaural Mode Setting Resistance Free-
Running Frequency

Free-running frequency kHz

Figure 3

LA1805

No.2887-4/13

2. VCO Stop

The VCO is so designed as to stop automatically at the

AM mode.

(when pin 11 and pin 21 are at the same potential)

There is no pin available for stopping the VCO at the

FM mode. However, the method shown right can be

used to stop the VCO at the FM mode, causing the

forced monaural mode to be entered.

3. Free-running frequency measurement and adjustment

Either of the following two methods is used to measure the

free-running frequency.

(1) Connect pin 13 to a frequency counter through the high

input impedance amplifier.

(2) Connect the connection point of the semifixed resistor

connected to pin 13 and the fixed resistor to a frequency

counter through the resistor of 240k

or greater.

Make the wiring as
short as possible.

Figure 4

Figure 5

Figure 6

How the error changes with the resistor value is

shown in Figure 7.

Resistor value, R

Measured error,

f %

Free-running frequency, f

kHz

IF input 100dBµ
Nonmodulation

· When setting the free-running frequency, the following must be noted.

Apply a 10.7MHz 100dBµ nonmodulation carrier as IF input signal and set to 76kHz±50Hz with the tuning indicator

lighted.

4. Separation setting capacitor Cs

The separation characteristic for the LA1805 alone

(IF input) differs from that for the antenna input

with a front end. This difference is caused by the

characteristics of the front end and ceramic filter.

Shown right is how the separation characteristic

changes with the separation setting capacitor value

when the LA1186N is used as front end. Referring

to this separation characteristic, choose the

optimum separation for your set model.

Figure 7

Figure 8

Separation, Sep dB

LA1805

No.2887-5/13

5. FM muting pin

The external resistor connected to pin 12 can be used to vary the muting level (Figure 9). The abnormal sound at the

time of side peak reception at the FM mode can be reduced by weak signal muting.

Input dBµ

LA1186N+LA1805 Muting Characteristics

Noise, Output dBm

Detuning frequency, f kHz

LA1186N+LA1805 Attenuation Detuning Frequency

Attenuation dB

Noise

6. The following method can be used to change the LED ON sensitivity at the FM mode (Figure 11). The data on the

LED ON sensitivity setting resistance and LED ON sensitivity is shown in Figure 12.

7. AM-FM selection

The FM mode is entered with pin 11 open as shown in

Figure 13. When pin 11 and pin 21 are made to be at

the same potential in terms of DC, the AM mode is

entered. It should be noted that the dynamic range is

narrowed whether the potential at pin 11 is lower or

higher than that at pin 21.

8. If a noise appears in the detection output when the tuning LED goes ON at the AM mode, connect a capacitor across

pin 8 and GND to eliminate the noise.

Resistance, R

LED ON Sensitivity R

LED ON sensitivity dB

Reference (R=Open)

Figure 11 Method to Change the LED ON

Sensitivity at the FM Mode

Unit (capacitance : F)

Figure 13

Figure 9

Figure 10

Figure 12

LA1805

No.2887-6/13

FM Characteristics

Input dBµ

Input dB/m

Detuning frequency,

f kHz

Total harmonic distortion, THD %

Noise, AM output, Demodulation output dBm

Attenuation dB

Modulation frequency Hz

Response dB

Total harmonic distortion, THD %

Whistle Characteristic

Fidelity Characteristics

Selectivity Characteristic

Noise, Detection output dBm

AM Characteristics

Noise

Output 20mV const.

input const.

Tracking at each frequency

Input dB/m

Detection output, Whistle output dBm

MW Reception Characteristic

Receiving frequency kHz

Sensitivity dB/m, Interference ratio dB

Detection output (1kHz-30% mod)

Max. whistle (2f1)

Demodulation output

AM output

Noise

Detection output

IF interference

Image frequency

interference

Usable sensitivity

Max. sensitivity (1kHz-30% mod, output=20mV)

LA1805

No.2887-7/13

FM V

Characteristics

Supply voltage, V

Ambient temperature, Ta °C

Capture range %

Supply voltage, V

Ambient temperature, Ta °C

Detection output dBm

Sensitivity dB

FM Temperature Characteristics

Sensitivity dB

AM V

Characteristics

Supply voltage, V

Detection output dBm

Sensitivity dB/m

Temperature Characteristics

Lamp ON Sensitivity V

Sensitivity dB

S/N dB

Total harmonic distortion, THD %

Output dBm

Total harmonic distortion, THD %

Detection output (100% mod)

Demodulation output

Max. sensitivity
(output=20mV, 30% mod)

Output 20mV sensitivity, 1kHz-30% mod

LED ON sensitivity

Demodulation output, input=100dB

LED ON sensitivity

THD (100% mod)

LED ON sensitivity

S/N, input=100dB

THD, input=100dBµ

Detection output, input=60dBµ

THD, input=100dB

µ, 1kHz-30% mod

Input

S/N, input=60dBµ

S/N=20dB sensitivity, 1kHz-30% mod

LED sensitivity

Pilot level mV

ON level

Supply voltage, V

Pilot modulation %

OFF level

Supply voltage, V

Separation, Sep dB

IF input 100dBµ

IF input
Nonmodulation

LA1805

No.2887-8/13

Supply voltage, V

Total harmonic distortion, THD %

IF input 100dBµ (10.7MHz)

Frequency, f Hz

Total harmonic distortion, THD %

IF input 100dBµ

Supply voltage, V

Carrier leak dB

IF input 100dBµ
0dB : mono output level

Modulation, Dev. kHz

Total harmonic distortion, THD %

IF input 100dBµ

Frequency, f Hz

Separation, Sep dB

IF input 100dBµ

without de-emphasis

carrier leak

Stereo (pilot modulation)
with de-emphasis

Carrier Leak V

IEC input dBµ

Pin4 voltage, V4 V

Total harmonic distortion, THD %

Adjust so that THD

is minimized.

SW2 Characteristics

IEC input dBµ

Noise voltage, Detection output dBm

SW2 Characteristics

Ambient temperature, Ta °C

Free-running frequency drift,

f %

IF input 100dBµ
Nonmodulation

Free-Running Frequency Drift Characteristic

Detection output (30% mod)

Noise

LA1805

No.2887-9/13

Receiving frequency, f

MHz

Oscillation voltage, V

OSC

Pin 24 voltage

SW2 Characteristic

ANT input dB/m

Noise output, Detection output dBm

Demodulation output

LW Characteristics

ANT input dB/m

Pin 4 voltage, V4 V

Total harmonic distortion, THD %

Receiving frequency, f

kHz

Oscillation voltage, V

OSC

LW Characteristics

Sensitivity dB/m Interference ratio dB

LW Characteristics

Receiving frequency, f

MHz

Interference ratio dB Sensitivity dB

Usable sensitivity

SW2 Characteristics

Max. sensitivity

Image frequency

interference

SW Band Test Circuit

T1 : YT-30117 (Mitsumi), 2158-4095-319A (Sumida)
T2 : HW-40184 (Mitsumi), 0237-1500 (Sumida)

Unit (capacitance : F)

Noise

Usable

sensitivity

Max. sensitivity

Image frequency

interference

LW Band Test Circuit

Unit (capacitance : F)

(Mitsumi)
(Mitsumi)

LA1805

No.2887-11/13

Sample Printed Circuit Pattern

(See Sample Application Circuit.)

Unit (resistance :

, capacitance : F)

ANT input voltage dBµ

Detection output, Noise voltage dBm

Detection output

LA1186N + LA1805 Over Characteristics

ANT input voltage dBµ

Total harmonic distortion, THD %

LA1186N + LA1805 Over Characteristics

AM output

Noise voltage

Differences between LA1805 and LA1806

(1) Same pin assignment
(2) The internal circuit of the MPX OUT (pin 9, pin 10) is different as shown below.

The FM S curve at pin 17 is in the opposite direction and the circuit in which AFC is provided is the same for the
US band and Japanese band.

(Cu-foiled area)

The LA1805 contains the output load resistors
(Output load resistance=6.8k

)

For the LA1806, output load resistors R

, R

are connected-

xternally. The graph of demodulation output vs. R

) is

shown below.

LA1805

No.2887-12/13

Coil Specifications

· MW bar antenna

TN-10896 (Mitsumi)

· AM IFT

HW-6215 (Mitsumi)

· SW2 OSC

HW-40184 (Mitsumi)

0237-1500 (Mitsumi)

· SW2 ANT

YT-30117 (Mitsumi)

2158-4095-319A (Sumida)

· MW OSC

HW-6193 (Mitsumi)

· FM quadrature

YT-30103 (Mitsumi)

HW-6194
SFU-450B

External load resistance, R

Demodulation output mVrms

LA1806 FM Characteristic

· LW bar antenna

HH-50161 (Mitsumi)

· LW OSC

MA-7014 (Mitsumi)

LA1805

No.2887-13/13

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 responsibilty 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 guarant-

eed 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 January, 1998. Specifications and information herein are subject

to change without notice.

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