| 摘要 |
1465225 Analogue - to - digital conversion ROCKWELL INTERNATIONAL CORP 30 Sept 1975 [18 Nov 1974] 40005/75 Heading H3H In an A-to-D converter a reference current Ip is switched to a summing point, to be summed with input current I A the sum being integrated, or is dumped by a switching circuit 49 dependent on a clocked flip-flop 51 receiving an up/ down signal from comparator 77 where the integrated voltage is compared with a triangle waveform. In the embodiment, for a bipolar input, input I A , bias I B and reference I P are summed and integrated through an inverting input of amplifier 57. Comparator 77 takes V O and a triangle waveform and gives an up signal when V O is greater. On the next clock pulse after a signal change outputs Q, Q of flip-flop 51 copy and F.E.T.'s 45, 47 dump the reference if Q is up. Q also passes to clocked AND gates where complementary bursts of pulses are passed to a counter or computing device. In a modification (Fig. 4, not shown) the AND gates are replaced by a flip-flop receiving a first clock pulse to copy flip-flop 51 and a second asynchronous pulse to produce output pulses. |
