| 摘要 |
PURPOSE:To transmit a quantized error voltage to an A/D converter at the post stage uniformly over the entire band, by compensating a frequency characteristic in the process generating a quantized analog voltage through a D/A converter from the prestage A/D converter. CONSTITUTION:An input signal applied to an input terminal 1 is roughly quantized at a prestage A/D converter 3, enters a coding circuit 7, becomes an analog signal through a D/A converter 4, the difference between an input signal and a signal delaying the input signal with an analog delay circuit 9 is picked up, fine quantization is made at a post atage A/D converter 6 and enters a coding circuit 7 and a digital output is picked up from a terminal 8. A compensation circuit 10 having a frequency characteristic to increase the gain at high frequency is inserted between the D/A converter 4 and the differential amplifier 5 to make the frequency characteristic almost constant. |
