Philips LX3600D Service Manual

AMPLIFIER BOARD
TABLE OF CONTENTS
Class-D Amplifier circuit description ................................................. 8-1
Exploded view + mechanical parts ................................................... 8-2
Amplifier circuit ..................................................................................8-3
Clock Generator & connector - circuit ............................................... 8-4
Bottom view .......................................................................................8-5
Top view ............................................................................................. 8-6
Bottom view Part A ............................................................................ 8-7
Bottom view Part B ............................................................................ 8-8
Top view Part C ................................................................................. 8-9
Top view Part D ............................................................................... 8-10
Electrical parts list - Amplifier board ............................................... 8-11
8-1
8-1
6-channel class-D amplifier
Basic operation of a class-D amplifier
Basically, the output stage of a class-D amplifier outputs a continuous square wave swinging between positive and negative power supplies
with a fixed frequency (“clock” frequency) far beyond the audible range. The duty cycle of this square wave is modulated with the audio signal.
The output is followed by a low-pass filter which eliminates the clock frequency and allows only the audio signal going to the speaker. See
simplified drawing below.
Compared to a conventional power amplifier the benefits of the Class-D amplifier are:
• higher effiency
• lower power dissipation
• smaller heatsink required
• smaller mains transformer required
The main disadvantage of this concept is:
• The amplifier is operating with a high-frequency square wave at high amplitude and currents. This requires special precautions to prevent
excessive electromagnetic ratiation (EMC).

Philips LX3600D Specifications

Picture/Display

aspect ratio	4:3, 16:9

Sound

D/A converter	24 bit, 96 kHz
frequency response	30-20000 Hz
output power (RMS)	6 x 50 W

Loudspeakers

satellite speaker freq range	120-20000 Hz
satellite speaker impedance	4 ohm
subwoofer freq range	30-120 Hz

Video Playback

number of discs	1
video disc playback system	NTSC, PAL
video enhancement	Progressive Scan

Audio Playback

compression format	Dolby Digital, DTS, MP3, PCM
MP3 bit rates	32-256 kbps and VBR
playback media	CD, CD-R, CD-RW, MP3-CD

Tuner/Reception/Transmission

auto digital tuning	Yes
number of preset channels	20
tuner bands	FM Stereo, MW

Power

power supply	110-240V, 50/60 Hz
standby power consumption	< 2 W
total sound power (RMS)	300 W

Dimensions

center speaker dimensions (W x H x D)	234 x 96 x 70 mm
set dimensions (W x H x D)	360 x 54 x 316 mm
subwoofer dimensions (W x H x D)	220 x 230 x 360 mm