Functional Description; Source Select Switches Block; Loudspeaker Channel; Effect Controls - Daewoo DDT-21H9ZDF(21") Service Manual

4-3-6- FUNCTIONAL DESCRIPTION

The TDA9859 consists of the following functions:
- Source select switching block
- Loudspeaker channel with effect controls
- Two port outputs for general purpose
2
- I C-bus control.
- Two general purpose logic output ports
2
- I C-bus control of all functions.

4-3-7- Source select switches block

The TDA9859 selects and switches the input signals from three stereo or six mono sources MAIN,AUX
and SCART (seeFIG.1)to the outputs SCART and loudspeaker(crossbar-switching;Table 4). The
main channel(LINE 0utputs) is looped outside the circuit(from pins 9 and 24 to pins 10 and 23), so signals
can as LINE output or a surround sound decoder can inserted.

4-3-8- Loudspeaker channel

Volume control is divided into volume control common and volume control left/right. The common part
(-40 to +15 dB) controls the left and right channels simultaneously;the left/right part(-23 to 0 dB) controls
the volume of left and right channels independently. treble control provides a control range from -12 to +12
dB and bass control from -12 to +15 dB. Extended bass control can be provded an external T-network(see Fig.1)
from -15 to +19 dB (2 dB steps).

4-3-9- Effect controls

'Linear stereo', 'stereo with spatial effect(30% or 52% anti-phase crosstalk)' and 'forced mono with or without
pseudo-stereo effect' are controlled by three bits. A muting of 85 dB is provided.
2
4-3-10- I

C-bus conrol

All settings of control of control and in subaddress registers. Data transmission is simplified by auto-
incrementing the subaddresses. The on-chip Power-on reset the mute bit to active, both SCART and the
loudspeaker outputs and muted.
The muting can be switched off by writing a '0'(non-muted) into the control bits.
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Service Manual CP-099/FS