High-speed analogueߝdigital convertor

The conversion time of fast analogue-digital convertors which use the successive-approximation conversion method is usually limited by the time the discriminator takes to respond with the required accuracy. The ratio of discriminator overload to required accuracy for any particular operation can be improved by the use of an error-correction system. This improvement has been exploited to obtain a faster response time from the discriminator, and a 7-bit convertor has been constructed which achieves a sampling rate of 9 Mc/s. The convertor speed is twice that which could be obtained from its Goto-pair tunnel-diode discriminator in a less complex successive-approximation system.