| 摘要 |
PURPOSE:To obtain a binary code digital signal where the number of output bits is increased by quantizing a voltage subtracting a minimum value voltage of the 1st quantizer corresponding to an input analog signal level from an input analog signal at the 2nd quantizer. CONSTITUTION:An A/D converting circuit 10 converts the input analog signal into a digital signal of, e.g., binary 4-bit, a reference voltage generating circuit 20 outputs a maximum value voltage of quantized level of the circuit corresponding to the output and a reference voltage generating circuit 30 outputs a minimum value voltage of the quantized level of the circuit. Further, a binary 3-bit A/D converting circuit 40 to which a voltage formed by subtracting the minimum voltage outputted from the circuit 30 from the input signal level of the circuit 10 is applied as an input signal and which quantizes a voltage in a voltage range of difference between the maximum and minimum value voltage from the corresponding circuits 20, 30, is provided. A 7-bit binary code digital signal is obtained from the circuits 10 and 40 and high quantization is attained. |
