| 摘要 |
For the dynamic compensation of the offset voltage in such converters each non-inverting comparator input (+) is connected via a first transfer transistor (T11, T12, T1p) to the signal input (SE) and via a second transfer transistor (T21, T22, T2p) to the associated voltage divider tap of the voltage divider as applied to the reference voltage (Ur). Moreover, each inverting comparator input (-), via a capacitor (C1, C2, Cp) is applied to the associated voltage divider tap and, via a third transfer transistor (T31, T32, T3p) and across a resistor (R'1, R'2, R'p) arranged in series therewith, to the associated comparator output. The second and third transfer transistors are rendered conductive during short intervals (T) between conversions by the clock signal (F), and the first transfer transistors are rendered non-conductive via the inverter (IV), and during the conversion time (t) the first transfer transistors are rendered conductive, and the second and third transfer transistors are rendered non-conductive. In television receivers, such MOS parallel A/D converters are suitable for processing the video signal, in which case the line sweep period serves as the conversion time (t), and the line fly-back period serves as the interval (T) between conversions.
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