| 摘要 |
PURPOSE:To reproduce economically an original signal with fidelity independently of a large or a small signal by using a D/A converter processing a bit number less than that of the original signal. CONSTITUTION:High-order plural bits including the most significant code bit of a digital signal S1 are used, decision circuit 4 decides the number of shift, gives a shift signal S6 to a selection circuit 2 and an amplification signal S7 to a variable amplifier 5. The selection circuit 2 to which a numeral part bit of the digital signal S1 is inputted used the shift signal S6 to shift the bit arrangement and build the numeral part of a selected digital signal S2 having a bit number less than that of the digital signal S1 thereby giving the result to a D/A converter. The sign bit of the digital signal S1 is fed to the most significant input of the D/A converter 3 as it is. The D/A converter 3 D/A- converts the selected digital signal S2 matching the sign bit, gives a linear analog signal S3 to the variable amplifier 5, amplifies the linear analog signal S3 in response to the amplification factor signal S7 to form an output analog signal S$ close to the original signal and sends the result from a speaker 7 as sound.
|
