Demodulation filter

Details Demodulation filter Demodulation filter

2001-05-24

2002-07-02

Pascal, Robert (Department: 2817)

Amplifiers

Modulator-demodulator-type amplifier

C330S20700P

Reexamination Certificate

active

06414544

ABSTRACT:

FIELD OF THE INVENTION
The invention relates to a push-pull amplifier as described in the pre-amble of claim
1
. The invention further relates to a demodulation filter for use in a push-pull amplifier.
From European Patent application EP-A-0776088 an amplifier output stage is known having a demodulation filter. Herein a demodulation filter comprises inductances and capacitances to demodulate the signal before supplying to a load, for example a loudspeaker.
Further from a publication “A review and Comparison of Pulse Width Modulation (PWM) Methods For Analog and Digital Switching Power Amplifiers” of K. Nielsen 102 AES Convention, Munich March 1997, Preprint 4446 also a demodulation filter is known.
A disadvantage of such an amplifier and demodulation filter is that the described demodulation filter operates for common mode signals as an oscillating loop, and has a peaking in the common mode operation.
SUMMARY OF THE INVENTION
It is an object of the invention to provide a push-pull amplifier not having these disadvantages. To this end a push-pull amplifier according to the invention comprises the features of claim
1
.
The demodulation filter according to the invention overcomes these disadvantages by introducing a common mode damping without influencing the differential mode.
The invention further relates to a demodulation filter for use in such a push-pull amplifier.
Further embodiments of the invention are described in the dependent claims.
Herewith a cross-reference is made to the following co-pending applications of the same applicant and of the same date:
“Carrousel handshake” applicant's ref. Nr. ID603908, Application No. 0 201 818.2
“Level shifter” applicant's ref. Nr. ID604680, Application No. 0 201 826.5
“Silent start” applicant's ref. Nr. ID604681, Application No. 0 201 827.3
“PWM limiter” applicant's ref. Nr. ID604682, Application No. 0 201 828.1.


REFERENCES:
patent: 4724396 (1988-02-01), Taylor, Jr. et al.
patent: 6016075 (2000-01-01), Hamo
patent: 6300825 (2001-10-01), Dijkmans et al.
patent: 0776088 (1997-05-01), None

Affiliated with

Also associated with

Rating

Demodulation filter does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Demodulation filter, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Demodulation filter will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2891097