Bastelbruder: dachte ich auch, dass man die Gegenkopplung amAusgang der Filterung anschliessen soll, doch ich hab vorher nach Application Notes über das Thema gesucht, und in der AN1042/D von ONSemi steht:
The negative feedback loop is closed before the filter to
prevent instabilities. Feedback cannot be taken from the
speaker because of the phase shift of the output filter, which
varies from 0° at dc to nearly 360° at 120 kHz. Since the
filter is linear, feedback may be taken from the filter input,
which has no phase shift. Unfortunately, this point is a high
frequency square wave which must be integrated to
determine its average voltage. The input is mixed with the
square wave output by resistors R4 and R5 shown in Figure
2. The resultant signal is integrated, which accurately
simulates the effect of the output filter. The output of the
integrator will be zero only if the filter input is an accurate
inverted reproduction of the amplifier input.
Der IR2104S hat folgende
Features
• Floating channel designed for bootstrap operation
Fully operational to +600V
Tolerant to negative transient voltage
dV/dt immune
• Gate drive supply range from 10 to 20V
• Undervoltage lockout
•3.3V, 5V and 15V input logic compatible
•Cross-conduction prevention logic
• Internally set deadtime
• High side output in phase with input
• Shut down input turns off both channels
• Matched propagation delay for both channels
