Circuit Description Of Digital Amp. Section - Pioneer XV-DV232 Service Manual

5

7.1.11 CIRCUIT DESCRIPTION OF DIGITAL AMP. SECTION

TAS5508APAG
Filter
PCM Signal and
Volume
From
DVD or ADC
PWM Processor section
PWM Processor section
The PCM signals output from the DVD decoder or AD converter are input to this section, and their volume and sound
quality are digitally adjusted. At the output stage, after conversion from PCM to PWM, the signals are output to the Power
stage.
Power Stage section
In this section, timing is controlled so that the MOSFETs on the high and low sides will not be turned on simultaneously.
The voltage of the PWM signals are raised to drive the gates of the MOSFET, and the PWM signals to drive the speakers
are output from the MOSFET at the output stage. Detection and protection functions against short-circuiting of the output
signals and temperature exceeding the standard value are also provided.
Output LPF section
The carrier elements, high-frequency signals that are unnecessary for these speakers, are eliminated. The signals passed
through the LPF will become sine-wave signals, as shown in the figure above.
Attention
As a signal to drive the BTL is output from the negative speaker terminal, DO NOT short-circuit between the
negative speaker terminal and ground, such as the chassis.
5
6
To UCOM
XSD
XOTW
PCM → PWM
LINE 2
R
FRONT
IN OUT
L L
R R
R
SURROUND
AUDIO WIRELESS
Negative Speaker Terminal
Do not short-circuit
Ground (Chassis)
6
7
3.3V
0V
TAS5122DCA
Gate
Drive
Timing
Control
Gate
Drive
Protection
Power Stage section
L
CENTER
SUB
L
WOOFER
SPEAKERS
XV-DV232
7
8
20V
0V
Output LPF section
AC IN
8
A
0V
B
0V
C
D
E
F
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