Kenwood KAC-PS650D Service Manual page 4

KAC-PS650D/X650D
Q301
UP-
GATE
DOWN-
GATE
Q301-304 convert voltage of up-gate and down-gate to current.
R379,380 convert the current to voltage, and Q308-311 drive MOS-FETs Q313,314.
Swung PWM wave form is output to ±B on line 6 , and the swung PWM wave form
is converted to analogue signal by LC filter.
4
CIRCUIT DESCRIPTION
Class-D Amplifier
Q308
Q306
Q307
Q309
Q303 Q304
Q302
Q305
R361
1K
R392
Q310
47
Q311
R380
820
1/2W
R499
Q439
1.5K
Q313
Q314
Q440
R500
1.5K
Q441
6
L301 L302
70uH 70uH
Q442