| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a class-D amplifier capable of performing dynamic range compression with a simple configuration without requiring an external circuit such as a variable resistor. <P>SOLUTION: An error integrator 110 integrates an error between an input signal and a feedback signal and outputs an integral value signal indicating an integral value. A pulse-width modulating circuit 130 outputs a digital signal having pulse width corresponding to the level of the integral value signal. An output buffer 150 drives a load based upon a digital signal output from the pulse-width modulating circuit 130. An output signal of the output buffer 150 is fed back to the error integrator 110. A compression characteristic control section 330 generates a compression characteristic control signal generated by multiplying a peak of Vin by a gain corresponding to a specified compression ratio, and adding a specified threshold. An attenuation instruction generating section 380 outputs an attenuation instruction pulse SW once the level of the output signal of the output buffer 150 exceeds the level of the compression characteristic control signal. <P>COPYRIGHT: (C)2011,JPO&INPIT |
