Boss Audio Systems CCR612

Philips Semiconductors

User Manual of High-End RDS/EON

Car Radio System CCR612 (V0.3) Application Note

96029

Isolator ( Differential Line Receiver, TDA8579T)

Dual common-mode rejection differential line receiver with 0 dB gain and low distortion. This device is

intendedto be used to receive line inputs in audio applications that require a high level ofcommon-mode

rejection. The device is encapsulated in an 8-pin SO or DIL package. In this set the isolator is used

between the external input and source selector input. Both the external input plug circuit and the

CD-changer input circuit are equipped with an isolator.

PACS - Sub Board (TEA6850)

PACScontrols the I.F. Selectivity / Bandwidth to avoid receiving problems due to near adjacent channels

(especiallyfor Europe, spacing of 100 kHz is not an exception). In order to show theimprovements of the

selectivityand dynamic behaviour of the radio by the use of PACS an ON/OFF switch has been used on

the front panel.

Acomplete circuit diagram of the PACS board is shown on page 94 and for description of the functions,

alignment and performance see Ref.5.

2.1.2 Main Board Part 1b (Optional Power Ampliﬁer,2 x TDA8561Q)

Page82 shows the previous circuit diagram (paragraph 2.1.1 Basic AM/FM stereo Radio Part) equipped

with circuits for 4 x 24W (4 ohm) audio output power.

Power Amplifier (2 x TDA8561Q)

Single circuit configuration 2 x 24W (4 ohm) bridge amplifiers, package SIL 17 pins Quil.

2.1.3 Main Board Part 1c (Optional Source Sel. & Audio Contr.

HEF4052B/TDA1526)

Page83 shows the circuit diagram from paragraph 2.1.1 (Basic AM/FM stereo Radio Part) equipped with

the DC controlled audio pre-amplifier (TDA1526) and a source selector circuit (HEF4052B).This set-up

is used in case potentiometer control for volume and tone is desired.

Audio Pre-Amplifier and DC Control (TDA1526).

An active stereo,tone/volume control for car radios. It includes functions for bass and treble, control,

volumecontrol with built in contour (can be switched off) and balance.All these functions can be controlled

direct by DC voltages or via single linear potentiometers.

Source selector circuit (HEF4052B).

TheHEF4052B isadual 4channelanalogue multiplexer/demultiplexerwithcommon channelselectlogic.

In this case used for four stereo inputs: radio, cassette and external input.