SANYO LA1837 Datasheet

Overview

The LA1837 is a single-chip AM/FM IF and MPX IC that supports electronic tuning and was developed for use in home stereo systems. It is optimal for use in automatic station selection systems that use the SD and IF counting techniques.

Functions

AM: RF amplifier, mixer, oscillator, IF amplifier,

detector AGC, oscillator buffer, S-meter, narrowband SD, IF buffer

FM IF: IF amplifier, quadrature detector, S-meter, S-

curve detector, IF buffer output

MPX: PLL stereo decoder, stereo display, forced mono,

VCO stop, post amplifier, audio muting, adjacent channel interference rejection function

Features

• On-chip MPX VCO (no external components required)

• Adjacent channel interference rejection function (third and fifth order)

• Supports both the SD and the IF counting techniques.

•

The AM and FM SD sensitivities can be set independently.

•

The AM and FM output levels can be set independently.

•

Improved AM practical sensitivity and high-input distortion characteristics

Package Dimensions

unit: mm

3061-DIP30S

Monolithic Linear IC

Ordering number : EN5688

82097HA(OT) No. 5688-1/9

SANYO: DIP30S

[LA1837]

SANYO Electric Co.,Ltd. Semiconductor Bussiness Headquarters

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

Single-Chip Home Stereo IC with

Electronic Tuning Support

LA1837

Parameter Symbol Conditions Ratings Unit

Maximum supply voltage V

max 12 V Allowable power dissipation Pd max Ta ≤ 70°C 550 mW Operating temperature Topr –20 to + 70 °C Storage temperature Tstg –40 to +125 °C

Specifications

Maximum Ratings at Ta = 25°C

Parameter Symbol Conditions Ratings Unit

Recommended supply voltage V

Operating voltage range V

op 7 to 11 V

Operating Conditions at Ta = 25°C

No. 5688-2/9

LA1837

Parameter Symbol Conditions

Ratings

Unit

min typ max

[FM Mono Characteristics] fc = 10.7 MHz, fm = 1 kHz, with the coil adjusted so that V

AFC

– V

REG

= 0 V

Current drain I

CCO

-FM

With no input 18 31 44 mA

Demodulation output V

100 dBµ, 100% mod. The pin 16 output 730 1100 1460 mVrms Channel balance C.B-mono 100 dBµ, 100% mod. The pin 16 output/pin 17 output –1.5 0 +1.5 dB Total harmonic distortion (mono) THD

FM(1)

100 dBµ, 100% mod. The pin 16 output 0.3 1.3 % Total harmonic distortion (mono) THD

FM(2)

100 dBµ, 200% mod. The pin 16 output 1.0 5 % Signal-to-noise ratio S/N

100 dBµ, 100% mod. The pin 16 output 72 80 dB AM rejection ratio AMR 100 dBµ, AM 30 % mod. The pin 16 output 45 65 dB

Limiting input voltage –3 dBL.S.

100 dBµ, 100% mod. Referenced to the output.

26 32 38 dBµ

The input such that the output is down –3 dB. LED sensitivity SD

On-FM

51 60 69 dBµ

LED bandwidth SD

100 dBµ 85 120 170 kHz IF count buffer output V

IFBuff-FM

100 dBµ. The pin 13 output 80 120 160 mVrms

S-meter output

SM-FM(1)

0 dBµ. The pin 11 output 0 0.1 0.5 V

SM-FM(2)

100 dBµ. The pin 11 output 3.6 4.3 5.0 V Muting attenuation Mute-Att 100 dBµ, 100% mod. The pin 16 output 75 85 dB [FM Stereo Characteristics] fc = 10.7 MHz, 100 dBµ, fm = 1 kHz, L + R = 90%, Pilot = 10% Separation (left) Sep

L mod. The pin 16 output/pin 17 output 30 45 dB Separation (right) Sep

R mod. The pin 17 output/pin 16 output 30 45 dB Stereo on level ST

The pilot modulation such that V7 is under 0.7 V. 1.3 2.7 5 % Stereo off level ST

OFF

The pilot modulation such that V7 is over 4.5 V. 1.5 % Total harmonic distortion (main) THD-main L+R mod. The pin 16 output 0.3 1.3 %

Brej-3rd

fs = 113 kHz, Vs = 90 %, Pilot = 10 %, The pin

40 dB

Adjacent channel interference

16 output vs. the L-R mod. 1 kHz demodulated output rejection ratio

Brej-5th

fs = 189 kHz, Vs = 90 %, Pilot = 10 %, The pin

40 dB

16 output vs. the L-R mod. 1 kHz demodulated output [AM Characteristics] fc = 1000 kHz, fm = 1 kHz

Current drain I

CCO-AM

With no input 15 25 35 mA

Detector output

OAM(1)

23 dBµ, 30% mod. The pin 16 output 100 180 360 mVrms

OAM(2)

80 dBµ, 30% mod. The pin 16 output 200 320 500 mVrms

Signal-to-noise ratio

S/N

AM(1)

23 dBµ, 30% mod. The pin 16 output 18 22 dB

S/N

AM(2)

80 dBµ, 30% mod. The pin 16 output 49 55 dB

Total harmonic distortion (mono)

THD

AM(1)

80 dBµ, 30% mod. The pin 16 output 0.4 1.2 %

THD

AM(2)

80 dBµ, 80% mod. The pin 16 output 1.0 4.0 % LED sensitivity SD

On-AM

17 27 37 dBµ

Local oscillator buffer output V

OSC-AM

With no input. The pin 30 output 110 160 220 mVrms IF counter buffer output V

IFBuff-AM

80 dBµ, no modulation. The pin 13 output 160 220 300 mVrms ST-IF output V

STIF-AM

80 dBµ, no modulation. The pin 7 output 16 34 48 mVrms S-meter output V

SM-AM

0 dBµ, no modulation. 0 0 0.2 V

Electrical Characteristics at Ta = 25°C, VCC= 9 V, in the specified Test Circuit

Allowable power dissipation, Pd max – mW

Ambient temperature, Ta – °C

Pd max – Ta

Block Diagram

No. 5688-3/9

LA1837

Test Circuit Diagram

FM SD

ADJ

3 rd 5 th

DECODER

ANTI-BIRDIE

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