| US 7,508,873 B2 | ||
| Digital amplifier, pulse width modulator thereof and method for reducing pop noise for the same | ||
| Tae Ho Kim, Seongnam-si (Korea, Republic of); and Jong Hoon Oh, Seoul (Korea, Republic of) | ||
| Assigned to Pulsus Technologies, Seoul (Korea, Republic of) | ||
| Filed on Jul. 28, 2005, as Appl. No. 11/192,293. | ||
| Claims priority of application No. 10-2005-0041101 (KR), filed on May 17, 2005. | ||
| Prior Publication US 2006/0262843 A1, Nov. 23, 2006 | ||
| Int. Cl. H03K 7/08 (2006.01); H03K 9/08 (2006.01) | ||
| U.S. Cl. 375—238 [327/31; 327/172; 327/173; 327/174; 329/312; 370/205; 370/212] | 15 Claims |
| 1. A pulse width modulator for use in a digital amplifier, comprising:
a pop noise reducer for reducing pop noise by controlling a width and a phase of a pulse of a pulse width modulation (PWM)
signal output from the pulse width modulator,
wherein the pop noise reducer includes:
a PWM pulse register for storing a width and a phase values of a pulse of the PWM signal; and
a pulse generator for outputting the PWM signal according to the values stored in the PWM pulse register
wherein a PWM amplifier of one of a PN half bridge type and a PN full bridge type using both a P channel MOSFET and an N channel
MOSFET is connected to an output port of the pulse width modulator and the pop noise reducer gradually increases the pulse
width of the PWM signal over at least two pulses when power is applied to the digital amplifier.
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