SANYO LA3242 Datasheet

Ordering number: EN 2620C

Monolithic Linear IC

LA3242

Preamplifier for Compact Cassette Recorder

Recording-only Use

Overview

The LA3242 is a preamp IC for compact cassette recorder
recording-only use. The distinctive feature of the LA3242 is
that it contains mechanical switches which have been so far
connected externally as peripheral parts.

Features

.

On-chip electronic select switches permitting selection of
normal/higher speed recording and metal(chrome)/normal
tape recording mode by using the dedicated control pins.

.

Two ALC output pins making it easy to make up a Dolby
recording system.

.

The control voltage from a microcomputer, etc. can be used
to turn ON/OFF the ALC and to set the ALC control voltage
to the initial value.

.

On-chip microphone amplifier making it easy to provide
microphone mixing.

.

Wide operating voltage range (VCC= 4.5 to 14.0 V).

.

Can be used in conjunction with playback-only preamp
LA3246 to make up a double-cassette dubbing system.

Functions

Package Dimensions

unit : mm

3067-DIP24S

[LA3242]

SANYO : DIP24S

.

Recording preamplifier ×2

.

Microphone amplifier ×1

.

ALC output ×2

.

Electronic switch ×6

Specifications

Maximum Ratings at Ta = 25°C

Parameter Symbol Conditions Ratings Unit
Maximum supply voltage V
Allowable power dissipation Pd max 720 mW
Operating temperature Topr –20 to +75 °C
Storage temperature Tstg –40 to +125 °C

Operating Conditions at Ta = 25°C

Parameter Symbol Conditions Ratings Unit
Recommended supply voltage V
Operating voltage range V

max 16 V

CC

CC

op 4.5 to 14.0 V

CC

6V

SANYO Electric Co.,Ltd. Semiconductor Bussiness Headquarters

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

D3097HA(II)/N257TA/7027TA,TS No.2620-1/12

LA3242

Operating Characteristics at Ta = 25°C, VCC= 6.0 V, RL=10kΩ,f=1kHz, 0 dB = 0.775 V

Parameter Symbol Conditions min typ max Unit
Quiescent current I
Quiescent current I

CCO
CCS

[REC Amp]

Voltage gain (Open) VG
Voltage gain (Closed) VG1 V
Total harmonic distortion THD 1 V
Maximum output voltage V
Equivalent input noise

voltage
Input resistance R

Crosstalk
Channel balance V

max THD = 1% 0.7 1.0 V

O

V

NI

I

CT1 Between REC amps 50 60 dB
CT2 REC amp→Microphone amp 50 75 dB

BL

[Microphone Amp]

Voltage gain (Open) VG
Voltage gain (Closed) VG2 V
Total harmonic distortion THD2 V
Maximum output voltage V
Equivalent input noise

voltage
Input resistance R

max THD = 1% 0.8 1.1 V

O

V

NI

I

Crosstalk CT3 Microphone amp→REC amp 45 60 dB

[ALC]

ALC range ALC
ALC balance ALC

ALC distortion ALC
ALC output voltage ALC
Crosstalk CT4 Between REC amps 45 60 dB
Crosstalk CT5 REC amp→Microphone amp 50 70 dB
ALC ON-state voltage ALCon Voltage on pin 17 1.0 V
ALC OFF-state voltage ALCoff Voltage on pin 17 1.5 V

[Switch]

ON-state resistance R
DC feedback resistance R

ON
F

Me/Nor, Nor/High SW OFF 5 7.5 12 mA
Me/Nor, Nor/High SW ON 12 16 20 mA

17585dB

O

= 0 dBm 42.5 44.5 46.0 dB

O

= 0.4 V 0.1 0.7 %

O

1 Rg = 2.2 kΩ, B.P.F = 20 Hz to 20 kHz 1.1 1.7 µV

1 405060kΩ

VIN= –50 dBm 0 2 dB

26070dB

O

= 0 dBm 23 25 27 dB

O

= 0.4 V 0.05 0.5 V

O

2 Rg = 2.2 kΩ, B.P.F = 20 Hz to 20 kHz 1.1 1.7 µV

2 405060kΩ

Input range when output distortion becomes 1%

W

after ALC begins to the applied.
Output difference between CH1 and CH2 0 2 dB

B

THDVIN

VO

= –40 dBm 0.15 0.8 %

VIN= –40 dBm 0.33 0.42 0.53 V

40 45 dB

30 70 Ω

1 405060kΩ

Allowable power dissipation, Pd max – mW

Pd max – Ta

Ambient temperature, Ta – °C

No.2620-2/12

Equivalent Circuit Block Diagram

LA3242

Equivalent Circuit

Top view

No.2620-3/12

Sample Application Circuit

LA3242

Note:

1. The electronic select switching level is approximately (V

2. REC amplifier NF parameters Z1 through Z3 should be selected to accommodate the recording level and frequency response
that will be required in metal/normal tape and normal/higher speed modes.

3. Z1 through Z3 may be configured with coil ‘‘L’’, capacitor ‘‘C’’, and resistor ‘‘R’’.

4. When electronic control pins 9 and 16 are at the GND level, each electronic switch is turned ON.

5. When ALC ON/OFF control pin 17 is at 1 V or less/1.5 V or greater, the ALC is turned ON/OFF, respectively (Ta = 25°C).

6. The ALC width depends on external resistor R

.

A

CC

– 0.9)/2.

No.2620-4/12