TEA0679 NXP Semiconductors, TEA0679 Datasheet - Page 2

• Manufacturer Part Number: TEA0679
• Description: I2c-bus Controlled dual Dolby* B-type Noise Reduction Circuit for Playback Applications
• Manufacturer: NXP Semiconductors

Philips Semiconductors
FEATURES
GENERAL DESCRIPTION
The TEA0679T 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. The device also includes electronically
switchable inputs for tape drivers with reverse heads.
This device 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).
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.
1998 Nov 12
V
I
TEA0679T
S
------------- -
CC
Dual Noise Reduction (NR) channels
Head preamplifiers
Reverse head switching
Automatic Music Search (AMS)
Blank skip
Mute position
Equalization with electronically switched time constants
Switch functions and level adjustment controlled via
I
Optional switch inputs TTL compatible
Dolby reference level = 387.5 mV
Contained in a 32-pin small outline package
Improved EMC behaviour.
CC
NUMBER
I
reduction circuit for playback applications
SYMBOL
2
N
+
2
C-bus
TYPE
C-bus controlled dual Dolby* B-type noise
N
supply voltage
supply current
signal plus noise-to-noise ratio
NAME
SO32
plastic small outline package; 32 leads; body width 7.5 mm
PARAMETER
DESCRIPTION
2
For both modes the delay time can be fixed by using an
external resistor. In the blank skip mode the IC can detect
pauses of music during playback and allows a
microcontroller to react on this situation.
The equalization amplifier gain adjustment, the output
offset adjustment and all switching functions are I
controlled. Head switching and equalization time constant
switching can be controlled via separate pins (optional).
The device operates with power supplies from 7.6 to 12 V.
The output overload level increases with increases in
supply voltage.
Current drain varies with the following variables:
Because of this current drain variation it is advisable to use
a regulated power supply or a supply with a long time
constant.
PACKAGE
Supply voltage
Noise reduction on/off
AMS on/off.
7.6
78
MIN.
35
84
TYP.
Product specification
TEA0679T
12
40
MAX.
SOT287-1
VERSION
V
mA
dB
2
C-bus
UNIT