| US 7,551,031 B2 | ||
| Amplifier | ||
| Masayuki Iwamatsu, Hamamatsu (Japan) | ||
| Assigned to Yamaha Corporation, Hamamatsu-shi (Japan) | ||
| Filed on May 28, 2008, as Appl. No. 12/154,944. | ||
| Claims priority of application No. 2007-143177 (JP), filed on May 30, 2007. | ||
| Prior Publication US 2008/0297257 A1, Dec. 04, 2008 | ||
| Int. Cl. H03G 3/12 (2006.01) | ||
| U.S. Cl. 330—282 [330/279] | 5 Claims |
| 1. An amplifier comprising:
a variable gain unit that adjusts amplitude of an input signal and outputs an output signal;
a negative feedback amplifying unit that includes an operational amplifier for amplifying the output signal of the variable
gain unit; and
a controller that compares a potential difference between a positive phase input terminal and a negative phase input terminal
of the operational amplifier with a reference potential and detects presence of clipping in the output signal of the negative
feedback amplifying unit-based on the result of the comparison to control the variable gain unit, thereby controlling the
clipping.
|