1996 Jun 07

2

Philips Semiconductors

Preliminary specification

Dual Dolby* B-type noise reduction circuit

for playback applications

TEA0675

FEATURES

• Dual noise reduction (NR) channels

• Head pre-amplifiers

• Reverse head switching

• Automatic Music Search (AMS)

• Music scan

• Equalization with electronically switched time constants

• Dolby reference level = 387.5 mV

• 24 pins

• Improved EMC behaviour.

GENERAL DESCRIPTION

The TEA0675 is a bipolar integrated circuit that provides

two channels of Dolby B noise reduction for playback

applications in car radios. It includes head and

equalization amplifiers with electronically switchable time

constants. Furthermore it includes electronically

switchable inputs for tape drivers with reverse heads.

This device also detects pauses of music in the Automatic

Music Search (AMS) scan mode, for applications with an

intelligent controlled tape driver, or AMS-latch mode, for

applications with a simple controlled tape driver. For both

modes, the delay time can be fixed externally by a resistor.

The device operates with power supplies in the range of

7.6 to 12 V, output overload level increasing with increase

in supply voltage.

Current drain varies with the following variables:

supply voltage

noise reduction on/off

AMS on/off.

Because of this current drain variation it is advisable to use

a regulated power supply or a supply with a long time

constant.

QUICK REFERENCE DATA

ORDERING INFORMATION

Remark Dolby*: Available only to licensees of Dolby Laboratories Licensing Corporation, San Francisco, CA94111,

USA, from whom licensing and application information must be obtained. Dolby is a registered trade-mark of Dolby

Laboratories Licensing Corporation.

SYMBOL

PARAMETER

MIN.

TYP.

MAX.

UNIT

supply voltage

7.6

−

12

V

supply current

−

26

31

mA

signal plus noise-to-noise ratio

78

84

−

dB

TYPE

NUMBER

PACKAGE

NAME

DESCRIPTION

VERSION

TEA0675

SDIP24

plastic shrink dual in-line package; 24 leads (400 mil)

SOT234-1

TEA0675T

SO24

plastic small outline package; 24 leads; body width 7.5 mm

SOT137-1

SN

+

N

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