Sharp LC-32LE511E, Service Manual

Page: 27 / 156

27
LC-32LE511
LC-40LE511
LC-40LE531
LC-32LE511
LC-40LE511
LC-40LE531
10
d. Pin Functions
C. SUBWOOFER AMPLIFIER STAGE (TPA3112)
a. General Description
The TPA3112D1 is a 25-W efficient, Class-D audio power amplifier for driving a bridge tied
speaker. Advanced EMI Suppression Technology enables the use of inexpensive ferrite bead
filters at the outputs while meeting EMC requirements. SpeakerGuard speaker protection
system includes an adjustable power limiter and a DC detection circuit. The adjustable power
limiter allows the user to set a "virtual" voltage rail lower than the chip supply to limit the
amount of current through the speaker. The DC detect circuit measures the frequency and
amplitude of the PWM signal and shuts off the output stage if the input capacitors are
damaged or shorts exist on the inputs. The TPA3112D1 can drive a mono speaker as low as
4����������������������������������������������� eliminates the need for an external heat
sink when playing music. The outputs are fully protected against shorts to GND, VCC, and
output-to-output. The short-circuit protection and thermal protection includes an auto-
recovery feature.
b. Features
• 25-W into an 8-���������������������������������������
• 20-W into an 4-�������at 10% THD+N From a12-V Supply
• 94% Efficient Class-D Operation into 8-������������������������������������
• Wide Supply Voltage Range Allows Operationfrom 8 to 26 V
• Filter-Free Operation
• SpeakerGuard™ Speaker Protection IncludesAdjustable Power Limiter plus DC Protection
• Flow Through Pin Out Facilitates Easy BoardLayout
• Robust Pin-to-Pin Short Circuit Protection andThermal Protection with Auto-Recovery
Option
• Excellent THD+N/ Pop Free Performance
• Four Selectable, Fixed Gain Settings
• Differential Inputs