SANYO LA1845N Datasheet

Ordering number : ENN7185

91002RM (OT) No. 5888-1/10

Overview

The LA1845N/1845NM is designed for use in mini
systems and is a single-chip tuner IC that provides
electronic tuning functions using SD/IF-count technigue.
It incorporates a pilot canceler and an adjustment-free
MUX VCO circuit, thus allows additional parts to be
reduced.

Functions

• AM: RF amplifier, mixer, oscillator, IF amplifier,
detector, AGC, SD, oscillator buffer, IF buffer,
stereo IF output, AGC time constant switch

• FM IF: IF amplifier, quadrature detector, S-meter, SD
(signal detection), S-curve detection, IF buffer
output

• MPX: PLL stereo decoder, stereo display, forced
monaural, VCO stop, audio muting, adjacent
channel interference rejection function, pilot
canceler

Features

• Integrated MPX VCO (ceramic resonators are no longer

required.)

• Built-in adjacent channel interference rejection function

(114 kHz, 190 kHz)

• Supports both SD and IF-count techniques

• Both FM SD sensitivity and bandwidth can be set

• Pilot canceler built in.

Package Dimensions

unit: mm

3067A-DIP24S

unit: mm

3112A-MFP24S

112

24

13

12.5

(0.75)

1.0

0.15

0.35

5.4

7.6

0.63

1.7max

1.5

0.1

SANYO: MFP24S

[LA1845NM]

0.48

(3.25)

3.3

3.9max

0.51min

21.0

(0.71)

1.78

0.25

7.62

6.4

1

12

24

13

0.95

0.9

SANYO: DIP24S

[LA1845N]

LA1845N, 1845NM

SANYO Electric Co.,Ltd. Semiconductor Company

TOKYO OFFICE Tokyo Bldg., 1-10, 1 Chome, Ueno, Taito-ku, TOKYO, 110-8534 JAPAN

Single-Chip Home Stereo IC

Monolithic linear IC

Any and all SANYO products described or contained herein do not have specifications that can handle
applications that require extremely high levels of reliability, such as life-support systems, aircraft’s
control systems, or other applications whose failure can be reasonably expected to result in serious
physical and/or material damage. Consult with your SANYO representative nearest you before using
any SANYO products described or contained herein in such applications.

SANYO assumes no responsibility for equipment failures that result from using products at values that
exceed, even momentarily, rated values (such as maximum ratings, operating condition ranges, or other
parameters) listed in products specifications of any and all SANYO products described or contained
herein.

Specifications

Maximum Ratings at Ta = 25°C

Operating Conditions at Ta = 25°C

Operating Characteristics at Ta = 25°C, VCC= 8 V, in the specified test circuit.

No. 5888-2/10

LA1845N, 1845NM

Parameter Symbol Conditions Ratings Unit

Maximum supply voltage V

CC

max 9 V

Pd max Ta ≤ 45°C 400 mW

Allowable power dissipation Pd max Ta = 80°C (DIP) 400 mW

Pd max Ta = 80°C (MFP) 260 mw
Operating temperature Topr –20 to +80 °C
Storage temperature Tstg –40 to +125 °C

Parameter Symbol Conditions Ratings Unit

Recommended supply voltage V

CC

8 V

Operating supply voltage range VCCop Ta = 80°C 4.3 to 8.5 V

Parameter Symbol Conditions

Ratings

Unit

min typ max
[FM Mono Characteristics] fc = 10.7 MHz, Vi = 100 dBµ, fm = 1 kHz, Mod = 75 kHz
Current drain I

CCO-FM

With no input signal 20 30 40 mA

Demodulator output V

OFM

100 dBµ, 100% modulation, fm = 1 kHz 230 360 460 mVrms

Total harmonic distortion THD

FM

100 dBµ, 100% modulation, fm = 1 kHz 0.35 1.5 %

Signal-to-noise ratio S/N

FM

100 dBµ, 100% modulation, fm = 1 kHz 73 80 dB
AM rejection ratio AMR 100 dBµ, AM 30% modulation, fm = 1 kHz 47 65 dB
3 dB sensitivity 100 dBµ, 100% modulation, fm = 1 kHz, -3 dB input 32 40 dBµ
SD sensitivity 0% modulation 38 47 56 dBµ
IF counter buffer output V

IFBuff-FM

100 dBµ, the pin 13 output 80 120 160 mVrms
Mute attenuation Mute-Att 100 dBµ, 100% modulation, fm = 1 kHz 75 85 dB
[FM Stereo Characteristics] fc = 10.7 MHz, Vi = 100 dBµ, fm = 1 kHz, L + R = 90%, Pilot = 10%
Separation SepLLeft channel modulated. The pin 16 output/the pin 17 output 30 42 dB
Stereo on level ST

ON

The pilot modulation such that V7 falls under 0.7 V 1.5 3.5 5.5 %
Total harmonic distortion THD-main Left + right modulation. The pin 16 output. 0.45 1.5 %

fs = 113 kHz, Vs = 90%, pilot = 10%

Adjacent channel rejection ratio 1 Brej-3rd

The left - right modulation, demodulated output

36

dB

fs = 189 kHz, Vs = 90%, pilot = 10%

Adjacent channel rejection ratio 2 Brej-5th

The left - right modulation, demodulated output

41

dB

Carrier leak L + R = 90%, pilot = 10% reference, pilot = 10% output 38 44

dB
[AM Characteristics] fc = 1000 kHz, Vi = 80 dBµ, fm = 1 kHz, Mod = 30%
Current drain I

CCO-AM

With no input signal 13 27 39 mA

Detector output 1 V

OAM1

23 dBµ, 30% modulation, fm = 1 kHz 40 80 160 mVrms

Detector output 2 V

OAM2

80 dBµ, 30% modulation, fm = 1 kHz 90 160 230 mVrms

Signal-to-noise ratio 1 S/N

AM1

23 dBµ, 30% modulation, fm = 1 kHz 17 23 dB

Signal-to-noise ratio 2 S/N

AM2

80 dBµ, 30% modulation, fm = 1 kHz 46 52 dB

Total harmonic distortion 1 THD

AM1

80 dBµ, 30% modulation, fm = 1 kHz 0.4 1.1 %

Total harmonic distortion 2 THD

AM2

107 dBµ, 30% modulation, fm = 1 kHz 0.5 1.3 %
SD sensitivity 0% modulation 11 20 29 dBµ
Local oscillator buffer output V

OSC-AM

With no input signal 100 140 200 mVrms
IF counter buffer output V

IFBuff-AM

23 dBµ 140 285 400 mVrms

Block Diagram

AC Test Circuit

No. 5888-3/10

LA1845N, 1845NM

(8.0 to 9.0 V)

24 23 22

21

20 19

18

17 16 15

14 13

1 2

3

4 5

6

7 8 9

10 11 12

LA1845N/1845NM

OSC

BUFF

1000pF

6.8kΩ

5.6kΩ

39pF

20pF

AM-IN

(1MHz)

39MH

3.3µF

50Ω

22µ F

0.047µF

20k Ω

10µ F

20k Ω

4.7µF

1000pF

0.1µF

65k Ω

A

LPF

LPF

L

OUT

R

OUT

0dB

0.0047µF

0.015µF

50kΩ

50kΩ

0.01µF

0.047µF

300Ω

75Ω

FM-IN

(10.7MHz)

33µ F 0.047µF

HW6215

V-SD

V-ST

TU-LED

ST-LED

AM IF

10kΩ

FM

AM

SEEK V

CC

8.0V

MONO

1µF

1µF

3kΩ

AM/FM

IF-BUFF

1000pF

HW50425

A

0.047µF

600BEAS-10471

detector coil

Top view

0.015µF

1000pF

20pF

NORMAL

0.47

µF