Quiet power up and power down of a digital audio amplifier

Details Quiet power up and power down of a digital audio amplifier Quiet power up and power down of a digital audio amplifier

2007-12-25

2007-12-25

Choe, Henry (Department: 2817)

Amplifiers

Modulator-demodulator-type amplifier

C330S251000

Reexamination Certificate

active

11314203

ABSTRACT:
A closed loop audio amplifier system and method of powering up/down the system without producing audible artifacts are provided. During power up, a prebias voltage is provided to each output connected to a speaker to increase the voltage to a nominal output level. High impedance switches are then driven at a 50% duty cycle. Feedback from the output is supplied to a servo, which is enabled to fine tune the output voltage. Low impedance switches are then driven at a 50% duty cycle at a quarter cycle timing. The order of the feedback loop depends on which of the high or low impedance switches are driven. The prebias voltage is then removed before audio signals to be amplified are supplied to the system. Timing of driving of the switches is programmable. To power down, essentially the reverse sequence is provided.

REFERENCES:
patent: 6016075 (2000-01-01), Hamo
patent: 6300825 (2001-10-01), Dijkmans et al.
patent: 6476672 (2002-11-01), Berkhout
patent: 6504427 (2003-01-01), Midya et al.
patent: 6538590 (2003-03-01), Gaboriau et al.
patent: 6556159 (2003-04-01), Fei et al.
patent: 6593806 (2003-07-01), Melanson
patent: 6720825 (2004-04-01), Hansen et al.
patent: 6853325 (2005-02-01), Arizumi et al.
patent: 7161421 (2007-01-01), Honda
patent: 2005/0083115 (2005-04-01), Risbo

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